CN108028406B

CN108028406B - Solid ionically conductive polymer material

Info

Publication number: CN108028406B
Application number: CN201680040454.9A
Authority: CN
Inventors: M·A·齐莫尔曼
Original assignee: Ionic Materials Inc
Current assignee: Ionic Materials Inc
Priority date: 2015-05-08
Filing date: 2016-05-06
Publication date: 2022-01-18
Anticipated expiration: 2036-05-06
Also published as: CN108028406A; WO2016182884A1; KR20180039581A; EP3295503A4; EP3295503A1; SG10201811815VA; KR102594870B1; JP2021141074A; JP2018522083A; JP7510240B2

Abstract

The present invention relates to a solid ionically conductive polymer material having: a crystallinity of greater than 30%; a glassy state; and at least one cationic diffusing ion and at least one anionic diffusing ion, wherein each diffusing ion is mobile in the glassy state.

Description

Solid ionically conductive polymer material

Statement regarding federally sponsored research or development (not applicable)

Technical Field

The present invention relates generally to polymer chemistry, and in particular to solid polymer electrolytes and methods for their synthesis.

Background

The history of batteries is a history of slow progress and gradual improvement. Historically, battery performance, cost, and safety have been conflicting goals, requiring tradeoffs that limit the feasibility of end-use applications such as grid-level storage (grid-level storage) and mobile power supplies (mobile power). The demand for conversion batteries has reached the level of national interest, driving great efforts to provide safe electrochemical energy storage with higher energy density and lower cost.

Alessandro Volta invented the first real cell that became known as the "voltaic stack". It consists of pairs of zinc and copper disks stacked on top of each other, separated by a layer of cloth or cardboard immersed in brine as electrolyte. This finding, while not feasible, has led to an understanding of the role of electrochemical cells and electrolytes.

Since Volta, the inventors have made improvements to liquid electrolytes based on porous membranes filled with concentrated solutions of salts, bases or acids in water or organic solvents. These liquid electrolytes are often corrosive and/or flammable and, in many cases, thermodynamically unstable with the electrode material, leading to performance limitations and safety concerns. These challenges make solid-state electrolytes very attractive in battery development. Solid electrolytes can provide significant benefits such as no leakage of electrolyte, more flexible geometry, higher energy density electrodes, and improved safety.

Ceramics and glasses were the first solid materials discovered and developed to have ionic conductivity. There are other materials in the following, but all of them have the feature that sufficiently high ionic conductivity is only obtainable at very high temperatures. For example, Japanese Toyota has announced development work to adopt a new "crystalline super-ionic crystal", which is a glassy ceramic Li₁₀GeP₂S₁₂. However, this material has high conductivity only above 140 ℃, while ceramics have common problems of manufacturability and brittleness. The manufacturing challenges of ceramics can be particularly prohibitive for incorporating materials into battery electrodes.

Initial interest in polymer electrolytes was caused by the following findings in 1975 by professor Peter v.wright, which discovered that complexes of polyethylene oxide (PEO) can conduct metal ions. Soon, professor Michel Armand recognized the potential use of PEO lithium salt complexes in battery applications. The combination of PEO and lithium salt has been developed for many years. Examples of such materials are P (EO)_nLiBETI complexes. Over the past three decades, there have been many attempts to improve polyethylene oxide (PEO) - (CH)₂CH₂O)_n-electrical conductivity of the substrate. In these PEO-based materials, cation mobility is dominated by polymer segmental motion. This for PEOThe seed chain motion is actually a liquid-like mechanism, but chain entanglement and partial crystallization may give the electrolyte some solid bulk property (bulk property). However, segmental motion is essential for PEO to be ion-conductive.

Plasticized polymer-salt complexes were prepared by adding liquid plasticizers to PEO in such a way that there was a compromise between solid polymer and liquid electrolyte. The value of the room temperature conductivity is greatly increased due to the increased segmental motion, but this is at the expense of a deterioration of the mechanical integrity of the membrane and the presence of an increased corrosion reactivity of the polymer electrolyte to the metal electrodes.

Gel electrolytes are obtained by incorporating large amounts of liquid solvent/liquid plasticizer into a polymer matrix capable of forming a gel having a polymeric host structure. The liquid solvent remains in the matrix of the polymer and forms a liquid conductive path through the otherwise non-conductive solid polymer. Gel electrolytes can provide high room temperature conductivity, but suffer from similar disadvantages as mentioned for plasticized polymer electrolytes.

The rubbery electrolyte is actually a "polymer-in-salt" system; unlike "salt-in-polymer" systems, in which a large amount of salt is mixed with a small amount of polymer (i.e., polyethylene oxide (PEO), polypropylene oxide (PPO), etc.). The glass transition temperature of these materials can be low to maintain a rubbery or viscoelastic state at room temperature, which in turn provides high electrical conductivity through enhanced segmental motion. However, the complexed/dissolved salts may have a tendency to crystallize, thus preventing their use in practical electrochemical devices.

Composite polymer electrolytes are simply prepared by dispersing a small fraction of micro/nano-sized inorganic (ceramic)/organic filler particles into a conventional polymer host. The polymer acts as a first phase and the filler material is dispersed in a second phase. As a result of the dispersion, the ionic conductivity, mechanical stability and interfacial activity can be improved. The ionic conductivity is attributed to a decrease in the level of crystallinity of the polymer in the presence of the filler and a corresponding increase in segmental motion.

Polyelectrolytes comprise charged groups covalently bonded to the polymer backbone, which makes the oppositely charged ions very mobile. The charged groups are flexible through segmental motion, which is required for cation diffusivity.

Other polymer electrolytes include Rod-Coil Block polyimide (NASA research) and various polymer/liquid blends (ionic liquid/PVDF-HFP). Unfortunately, low conductivity at room temperature excludes all of these known polymer electrolytes from practical use because they require segmental motion to achieve ionic conductivity. Since the ionic conductivity of a typical polymer electrolyte depends on the temperature above the glass transition temperature (T) of the material_g) All attempts to make useful solid polymer electrolytes have therefore focused on inhibiting crystalline phases and/or reducing the temperature at which the glassy state transitions to a state capable of segmental motion (i.e., a viscoelastic state or a rubbery state).

In polymer-salt complexes where both crystalline and amorphous phases are present, ion transport occurs in the amorphous phase. The Vogel-Tamman-Fulcher (VTF) equation describes the behavior of ions diffusing through a polymer. The VTF equation is based on the assumption that ions are transported by semi-random motion of short polymer segments. The onset of this segmental motion is as a function of the temperature rise above the glass transition temperature T_gAnd occurs and becomes faster as the temperature increases in the viscoelastic state. Segmental motion is believed to facilitate ionic motion by disrupting the solvation of the ionic opposing (relative) multiple coordination sites on the polymer and providing space or free volume into which ions may diffuse. The fact that polymer segmental motion is essential for ion transport generally requires that such complexes be concentrated on amorphous materials with low glass transition temperatures.

Disclosure of Invention

According to one aspect, there is provided a solid ion conducting (ionicly conductive) polymeric material having a crystallinity of greater than 30%; a melting temperature; a glassy state; and at least one cationic and anionic diffusing ion(s), wherein each diffusing ion is mobile in the glassy state. The material may further comprise a plurality of (a plurality of) charge transfer complexes, and

a plurality of (a plurality of) monomers, wherein each charge transfer complex is located on a monomer.

The material may also have a surface roughness of less than 1.0X10 at room temperature⁵Ω·cm²Area specific resistance (area specific resistance).

In one aspect, there is provided a solid semi-crystalline ionically conductive polymer material having: a plurality of monomers; a plurality of charge transfer complexes, wherein each charge transfer complex is located on a monomer; and wherein the area specific resistance of the material is less than 1.0x10 at room temperature⁵Ω·cm². The material may have a crystallinity of greater than 30%; a glassy state that exists at a temperature below the melting temperature of the material; and a cationic diffusing ion and an anionic diffusing ion, whereby each diffusing ion is mobile in the glassy state.

According to other aspects of the solid ionically conductive polymer material, other aspects of the material may include one or more of the following features:

the charge transfer complex is formed by the reaction of a polymer and an electron acceptor;

the material having a glassy state and comprising at least one cationic and at least one anionic diffusing ion, wherein each diffusing ion is mobile in the glassy state;

the material comprises at least three diffusing ions;

the material comprises more than one anionic diffusing ion;

the melting temperature of the material is greater than 250 ℃;

the material has an ionic conductivity greater than 1.0x10 at room temperature^-5S/cm；

The material comprises a single cationic diffusing ion, wherein the diffusivity of said cationic diffusing ion is greater than 1.0x10 at room temperature^-12m²/s；

The material comprises a single anionic diffusing ion, wherein the diffusivity of said anionic diffusing ion is greater than 1.0x10 at room temperature^-12m²/s；

The material, wherein the at least one cationic diffusing ion comprises an alkali metal, an alkaline earth metal, a transition metal, or a post transition metal;

the material comprises at least one anionic diffusing ion/monomer;

the material comprises at least one cationic diffusing ion/monomer;

the material comprises at least 1 mole of cation diffusing ions per liter of material;

a charge transfer complex of the material is formed by reaction of a polymer, an electron acceptor and an ionic compound, wherein each cationic and anionic diffusing ion is a reaction product of the ionic compound;

the material is formed from at least one ionic compound, wherein the ionic compound comprises each of a cationic diffusing ion and an anionic diffusing ion;

the material is thermoplastic;

the cation diffusing ions of the material include lithium;

at least one cationic and at least one anionic diffusing ion of the material has a diffusivity, wherein the cationic diffusivity is greater than the anionic diffusivity;

the cation transference number of the material is more than 0.5 and less than 1.0;

the cation diffusing ion concentration of the material is greater than 3 moles of cations per liter of the material;

the cation diffusing ions of the material include lithium;

the diffusing cations of the material are monovalent;

the valence number of the diffusing cation is more than 1;

the material comprises more than 1 diffusing anion per monomer;

the diffusing anion of the material is hydroxide ion;

the diffusing anion of the material is monovalent;

the diffusing anion and diffusing cation of the material are monovalent;

at least one cationic diffusing ion and at least one anionic diffusing ion of the material have a diffusivity, wherein the anionic diffusivity is greater than the cationic diffusivity;

the cation transference number of the material is equal to or less than 0.5 and greater than zero;

the material has a diffusivity of at least one cationic diffusing ion greater than 1.0x10^-12m²/s；

The material has a diffusivity for at least one anionic diffusing ion greater than 1.0x10^-12m²/s；

The material has a diffusivity greater than 1.0x10 for at least one anionic diffusing ion and at least one cationic diffusing ion^-12m²/s；

Each monomer of the material comprises an aromatic or heterocyclic ring structure located in the backbone of the monomer;

the material further comprises a heteroatom incorporated into the ring structure or located on the backbone adjacent to the ring structure;

the material comprises heteroatoms selected from sulfur, oxygen or nitrogen;

the heteroatom of the material is located on the backbone of the monomer adjacent to the ring structure;

the heteroatom of the material is sulfur.

The material is pi-conjugated;

at least one anionic diffusing ion/monomer of the material, and wherein at least one monomer comprises lithium ions;

the material comprises a plurality of monomers, wherein the monomers have a molecular weight greater than 100 grams/mole;

the material is hydrophilic;

the ionic conductivity of the material is isotropic;

the material has an ionic conductivity greater than 1x10 at room temperature^-4S/cm；

The ionic conductivity of the material at 80 ℃ is more than 1x10^-3S/cm；

The ionic conductivity of the material at-40 ℃ is more than 1x10^-5S/cm；

The cation diffusing ions of the material comprise lithium, and wherein the diffusivity of the lithium ions is greater than 1.0x10 at room temperature^-13m²/s；

The material is non-flammable;

the material is unreactive when mixed with a second material, wherein the second material is selected from the group consisting of electrochemically active materials, electrically conductive materials, rheology modifying materials, and stabilizing materials;

the material is in a film shape;

the Young modulus of the material is equal to or more than 3.0 MPa;

the material becomes ionically conductive after being doped with an electron acceptor;

the material becomes ionically conductive upon doping with an electron acceptor in the presence of an ionic compound comprising a cationic and anionic diffusing ion, or is convertible to a cationic and anionic diffusing ion by oxidation of the electron acceptor;

the material is formed from the reaction product of a base polymer, an electron acceptor, and an ionic compound;

the base polymer of the material is a conjugated polymer;

the base polymer of the material is PPS or a liquid crystal polymer;

the ionic compound reactant of the material is an oxide, chloride, hydroxide or salt;

the charge transfer complex of the material is formed by the reaction of an electron acceptor and a polymer; and

the reactant electron acceptor of the material is a quinone or oxygen.

In one aspect, solid ionically conductive macromolecules and materials comprising the macromolecules are provided comprising:

a plurality of monomers, wherein each monomer comprises an aromatic ring structure or a heterocyclic ring structure;

a heteroatom incorporated into or positioned adjacent to the ring structure;

a cationic diffusing ion and an anionic diffusing ion, wherein both the cationic diffusing ion and the anionic diffusing ion are incorporated into the structure of the macromolecule;

wherein both the cationic and anionic diffusing ions can diffuse along the macromolecule;

wherein there is no segmental motion in the polymeric material as the cationic or anionic diffusing ions diffuse along the macromolecule.

Further, this aspect may include one or more of the following features:

the ionic conductivity of the material is more than 1x10^-4S/cm；

The molecular weight of each monomer is greater than 100 g/mol;

the at least one cationic diffusing ion of the material comprises an alkali metal, an alkaline earth metal, a transition metal, or a post-transition metal.

One aspect is a method of making a solid ionically conductive polymer material comprising the steps of: mixing a base polymer comprising a plurality of monomers, an electron acceptor, and an ionic compound to produce a first mixture; heating the first mixture to produce the solid ionically conductive polymer material.

Another aspect is a method of making a solid ionically conductive polymer material comprising the steps of: mixing a polymer comprising a plurality of monomers and a compound comprising an ion to produce a first mixture; doping the first mixture with an electron acceptor to produce a second mixture; and heating the second mixture.

Another aspect is a method of making a solid ionically conductive polymer material comprising the steps of: mixing a polymer comprising a plurality of monomers and an electron acceptor to produce a first mixture; heating the first mixture to produce an intermediate material comprising a charge transfer complex; mixing the intermediate material with an ion-containing compound to produce the solid ionically conductive polymer material.

Other aspects of the method of making a solid ionically conductive polymer material may include one or more of the following features:

an annealing step, wherein the crystallinity of the base polymer increases in said annealing step;

the base polymer comprises a plurality of monomers, and wherein the molar ratio of monomers to electron acceptors is equal to or greater than 1: 1;

the base polymer has a glass transition temperature, and wherein the glass transition temperature of the base polymer is greater than 80 ℃;

the weight ratio of the base polymer to the ionic compound in the mixing step is less than 5: 1;

applying a positive pressure to the mixture during the heating step;

the mixture undergoes a color change during the heating step;

forming a charge transfer complex in the heating step;

a further mixing step of mixing the solid ionically conductive polymer material with a second material;

an extrusion step, wherein the solid ionically conductive polymer material is extruded; and

an ion conducting step, wherein the solid ionically conductive polymer material transports at least one ion.

Additional aspects include: an electrochemically active material composite comprising the material of the preceding aspect and an electrochemically active material;

an electrode comprising the material of the foregoing aspect;

a battery comprising the material of the foregoing aspect;

a fuel cell comprising the material of the preceding aspect;

an electrolyte comprising the material of the preceding aspect;

a device for conducting ions comprising the material of the preceding aspect;

a method for conducting ions comprising the material of the preceding aspect; and

a method for separating ions comprising the material of the preceding aspect;

in another aspect, a new ion conduction mechanism is provided that is capable of conducting ions in both the crystalline and amorphous glassy states of a polymer, which can result in a solid polymer material having the electrical conductivity of a liquid at room temperature;

composite anodes and cathodes capable of being produced comprising the polymer and electrochemically active compounds to improve capacity and cycle life;

active materials with abundant sources and low cost can be used; and is

New cell fabrication methods using low cost, high volume extrusion and other plastic processing techniques can be implemented.

These and other aspects, features, advantages and objects will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.

Drawings

In the drawings:

fig. 1 is a graph of cycle testing of a lithium ion battery using an LCO cathode comprising a solid ionically conductive polymer material;

FIG. 2 is a graph of the discharge curve of example 6;

FIGS. 3A, 3B and 3C are X-ray diffraction patterns as described in example 9;

FIG. 4 is a DSC curve as described in example 10;

FIG. 5 is a graph of measured conductivity versus temperature as described in comparative example 13;

FIG. 6 is a graph of measured conductivity versus temperature as described in comparative example 13;

FIG. 7 is a graph of measured conductivity for a sample of the material described in example 14;

FIG. 8 is a plot of measured diffusivity versus temperature for a sample of the material described in example 16;

FIG. 9 is a NMR diffusivity profile for the comparative material described in example 17;

FIG. 10 is an NMR spectrum of the base polymer reactant described in example 18.

FIG. 11 is an NMR spectrum of the material described in example 18.

FIG. 12 is an NMR spectrum of the material described in example 18.

FIG. 13 is an NMR spectrum of the electron acceptor described in example 18.

FIG. 14A is an NMR spectrum of the material described in example 18.

FIG. 14B is an NMR spectrum of the material described in example 18.

FIG. 15 is an NMR spectrum of the material described in example 19.

Fig. 16 is an illustration of a battery using the material as described in example 19.

Fig. 17 is a discharge curve of three cells described in example 20.

Fig. 18 is a discharge curve of the battery described in example 21.

Fig. 19 is a discharge curve of the battery described in example 22.

Detailed Description

This patent application claims priority from U.S. provisional patent application No.62/158,841 filed on day 5, 8, 2015, the entire disclosure of which is incorporated herein by reference.

The following explanations of terms are provided to better describe in detail the aspects, embodiments, and objects that will be set forth in this section. Unless otherwise explained or defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. To facilitate reading of the various embodiments of the present disclosure, the following explanation of specific terms is provided:

depolarizers are synonyms for electrochemically active substances, i.e. substances which change their oxidation state during the electrochemical reaction and charge transfer step of the electrochemically active substance, or which participate in the formation or cleavage of chemical bonds. When the electrodes have more than one electroactive species, they may be referred to as co-depolarizers (codeprolizers).

Thermoplastics are a characteristic of a plastic material or polymer that becomes pliable or moldable above a certain temperature (often near or at its melting temperature) and solidifies upon cooling.

Solid electrolytes include solvent-free polymers and ceramic compounds (crystalline and glassy).

"solid" is characterized by its ability to retain its shape for an indefinite period of time, and is distinguished and distinct from liquid-phase materials. The atomic structure of a solid may be crystalline or amorphous. The solids may be mixed with or be a component of the composite structure. However, for the purposes of this application and its claims, a solid material requires that the material be ionically conductive through a solid rather than through any solvent, gel, or liquid phase, unless otherwise specified. For the purposes of this application and its claims, gel (or wet) polymers and other materials that rely on liquids to achieve ionic conductivity are defined as not solid electrolytes because they rely on liquid phases to achieve their ionic conductivity.

Polymers are typically organic and are composed of carbon-based macromolecules, where each of the carbon-based macromolecules has one or more repeat units or monomers. Polymers are lightweight, ductile, generally non-conductive, and melt at relatively low temperatures. The polymers may be formed into products by injection molding processes, blow molding processes and other forming processes, extrusion, pressing, stamping, three-dimensional printing, machining and other plastic processes. The polymers generally have a glassy state at temperatures below the glass transition temperature Tg. This glass transition temperature is a function of chain flexibility; and when there is sufficient vibrational (thermal) energy in the system, this glass transition temperature occurs to create sufficient free volume so that the sequence of segments of the polymer macromolecule can move together as a unit. However, in the glassy state of the polymer, there is no segmental motion of the polymer.

The polymer is different from the ceramic defined as an inorganic non-metallic material; which are generally brittle, strong, and non-conductive compounds composed of metals covalently bonded to oxygen, nitrogen, or carbon.

The glass transition that occurs in some polymers is the mid-point temperature between the supercooled liquid and glassy states upon cooling of the polymeric material. Thermodynamic measurements of glass transition are accomplished by measuring the physical properties (e.g., volume, enthalpy or entropy, and other derivative properties) of the polymer as a function of temperature. The glass transition temperature is observed on such curves as a disruption of the selected property (volume of enthalpy) or by a change in slope (heat capacity or coefficient of thermal expansion) at the transition temperature. Upon cooling the polymer from above Tg to below Tg, the migration speed of the polymer molecules slows down until the polymer reaches its glassy state.

Since a polymer may comprise both amorphous and crystalline phases, the polymer crystallinity is the amount of this crystalline phase relative to the amount of polymer and is expressed as a percentage. The percent crystallinity can be calculated by analyzing the relative areas of the amorphous and crystalline phases via X-ray diffraction of the polymer.

Polymer films are generally described as thin portions of polymer, but should be understood to be equal to or less than 300 microns thick.

It is important to note that ionic conductivity is not the same as electrical conductivity. The ionic conductivity depends on the ionic diffusivity, which are related by the Nerst Einstein equation. Both ion conductivity and ion diffusivity are measures of ion mobility. Ions are mobile in a material if their diffusivity in the material is positive (greater than zero), or it contributes to positive conductivity. All of these ion mobility measurements were performed at room temperature (about 21 ℃) unless otherwise noted. Since ion mobility is affected by temperature, it may be difficult to detect at low temperatures. The device detection limit may be a factor in determining the amount of small mobility. Mobility is understood to mean an ion diffusivity of at least 1x10^-14m²S, preferably at least 1x10^-13m²Both of which make the ions mobile in the material.

Solid polymeric ionically conductive materials are solids that contain polymers and conduct ions, as described further below.

One aspect of the present invention includes a method of synthesizing a solid ionically conductive polymer material from at least three different components: polymers, dopants, and ionic compounds. The components and methods of synthesis are selected for the particular application of the material. The choice of polymer, dopant and ionic compound may also vary based on the desired properties of the material. For example, the desired composition and method of synthesis may be determined by optimizing the desired physical properties (e.g., ionic conductivity).

Synthesizing:

the method of synthesis may also vary depending on the specific components and the desired form of the final material (e.g., film, particles, etc.). However, the method comprises the following basic steps: the method includes the steps of first mixing at least two of the components, adding a third component in an optional second mixing step, and heating the components/reactants to synthesize a solid ionically conductive polymer material in the heating step. In one aspect of the invention, the resulting mixture may optionally be formed into a film of desired dimensions. If no dopant is present in the mixture resulting from the first step, it may then be added to the mixture while heating and optionally applying pressure (positive pressure or vacuum). All three components may be present and mixed and heated to complete the synthesis of the solid ionically conductive polymer material in one step. However, this heating step may be done in a separate step from any mixing, or may be done while mixing is taking place. The heating step may be performed independently of the form of the mixture (e.g., film, granules, etc.). In one aspect of the synthetic method, all three components are mixed and then extruded into a film. The film was heated to complete the synthesis.

When synthesizing a solid ionically conductive polymer material, a visually observable color change occurs because the reactant color is a relatively light color, while the solid ionically conductive polymer material is a relatively dark color or black. It is believed that this color change occurs when a charge transfer complex is being formed; and this color change may occur gradually or rapidly depending on the synthesis method.

One aspect of the synthesis method is to mix the base polymer, ionic compound and dopant together and to heat the mixture in a second step. Since the dopant may be in the gas phase, the heating step may be carried out in the presence of the dopant. The mixing step may be carried out in an extruder, blender, mill or other equipment typical of plastic processing. The heating step may last for several hours (e.g., twenty-four (24) hours), and the color change is a reliable indication that the synthesis is complete or partially complete. Additional heating after synthesis does not appear to have a negative effect on the material.

In one aspect of the synthetic method, the base polymer and the ionic compound can be first mixed. The dopant is then mixed with the polymer-ionic compound mixture and heated. The mixture may be heated during the second mixing step or after the mixing step.

In another aspect of the synthetic method, the base polymer and dopant are first mixed and then heated. This heating step may be applied after or during mixing and produces a color change indicating the formation of the charge transfer complex and the reaction between the dopant and the base polymer. An ionic compound is then mixed into the reacted polymer dopant material to complete the formation of the solid ionically conductive polymer material.

Typical methods of adding dopants are known to those skilled in the art and may include gas phase doping (vapor doping) of thin films containing polymers and ionic compounds, as well as other doping methods known to those skilled in the art. Upon doping, the solid polymeric material becomes ionically conductive; it is believed that the doping acts to activate the ionic component of the solid polymeric material, which is thus a diffusing ion.

Other non-reactive components may be added to the mixture during the initial mixing step, the second mixing step, or the mixing step after heating. Such other components include, but are not limited to: depolarizers or electrochemically active materials such as anode or cathode active materials, conductive materials such as carbon, rheological agents such as binders or extrusion aids (e.g., ethylene propylene diene monomer "EPDM"), catalysts, and other components that can be used to achieve desired physical properties of the mixture.

Polymers useful as reactants in the synthesis of solid ionically conductive polymer materials are electron donors or polymers that can be oxidized by an electron acceptor. Semi-crystalline polymers with crystallinity indices greater than 30% and greater than 50% are suitable reactant polymers. Fully crystalline polymeric materials such as liquid crystal polymers ("LCPs") may also be used as reactant polymers. The LCP is completely crystalline, and therefore its crystallinity index is defined as 100%. Undoped conjugated polymers and polymers such as polyphenylene sulfide ("PPS") are also suitable polymer reactants.

The polymer is generally non-conductive. For example, native PPS has a value of 10^-20S cm^-1The electrical conductivity of (1). Non-conductive polymers are suitable reactant polymers.

In one aspect, the polymers useful as reactants may have an aromatic or heterocyclic component in the backbone of each repeating monomer group and a heteroatom incorporated into or located adjacent to the aromatic ring along the backbone. The heteroatoms may be directly on the backbone or bonded to carbon atoms directly on the backbone. In both cases where the heteroatom is located on the backbone or is bonded to a carbon atom located on the backbone, the backbone atoms are located on the backbone adjacent to the aromatic ring. Non-limiting examples of polymers for use in this aspect of the invention may be selected from PPS, polyphenylene oxide ("PPO"), LCP, polyetheretherketone ("PEEK"), polyphthalamide ("PPA"), polypyrrole, polyaniline, and polysulfone. Copolymers of monomers including the listed polymers and mixtures of these polymers may also be used. For example, copolymers of p-hydroxybenzoic acid can be suitable liquid crystal polymer base polymers. Table 1 details non-limiting examples of reactant polymers useful in the present invention, as well as monomer structure and some physical property information, which should be considered non-limiting, as the polymer may take a variety of forms that can affect its physical properties.

TABLE 1

In solid ion conductivityDopants that can be used as reactants in the synthesis of polymeric materials are electron acceptors or oxidants. It is believed that the dopant acts to release ions for ion transport and mobility, and is believed to act to generate sites similar to charge transfer complexes or sites within the polymer that allow ionic conductivity. Non-limiting examples of useful dopants are: quinones, for example 2, 3-dicyano-5, 6-dichlorodicyanoquinone (C), also known as "DDQ₈Cl₂N₂O₂) And tetrachloro-1, 4-benzoquinone (C), also known as chloranil₆Cl₄O₂) (ii) a Tetracyanoethylene (C) also known as TCNE₆N₄) (ii) a Sulfur trioxide (' SO)₃"); ozone (ozone or O)₃) (ii) a Oxygen (O)₂Including air); transition metal oxides (including manganese dioxide ("MnO"))₂")); or any suitable electron acceptor, etc.; and combinations thereof. Those dopants that are temperature stable at the temperature of the synthesis heating step are useful, and temperature stable quinones and other dopants and strong oxidant quinones are most useful. Table 2 provides a non-limiting list of dopants and their chemical diagrams.

TABLE 2

Ionic compounds useful as reactants in the synthesis of solid ionically conductive polymer materials are compounds that release the desired ion during the synthesis of the solid ionically conductive polymer material. Ionic compounds differ from dopants in that both ionic compounds and dopants are required. Non-limiting examples include Li₂O、LiOH、ZnO、TiO₂、Al₃O₂、NaOH、KOH、LiNO₃、Na₂O、MgO、CaCl₂、MgCl₂、AlCl₃LiTFSI (lithium bistrifluoromethanesulfonimide), LiFSI (lithium bis (fluorosulfonyl) imide), and lithium bis (oxalato) borate (LiB (C)₂O₄)₂"LiBOB") and other lithium salts and combinations thereof. Hydrated forms of these compoundsThe formula (e.g. monohydrate) can be used to simplify handling of the compound. Inorganic oxides, chlorides, and hydroxides are suitable ionic compounds because they dissociate during synthesis to produce at least one anionic and cationic diffusing ion. Any such ionic compound that dissociates to produce at least one anionic and cationic diffusing ion is also suitable. A variety of ionic compounds may also be useful, resulting in a variety of anionic and cationic diffusing ions may be preferred. The specific ionic compounds included in the synthesis depend on the desired use of the material. For example, in applications where it is desired to have lithium cations, lithium hydroxide or lithium oxide that can be converted to lithium ions and hydroxide ions would be suitable. Any lithium-containing compound that releases a lithium cathode and diffuses anions during synthesis would also be suitable. Non-limiting examples of such lithium ion compounds include those used as lithium salts in organic solvents. Similarly, in those systems where aluminum or other specific cations are desired, the aluminum or other specific ionic compounds react during synthesis to release the specific desired ion and diffuse anion. As will be further demonstrated, ionic compounds comprising alkali metals, alkaline earth metals, transition metals, and post-transition metals in a form that can produce the desired cationic and anionic diffusing species are suitable as the synthesis reactant ionic compounds.

The purity of the material is potentially important to prevent any undesirable side reactions and to maximize the effectiveness of the synthesis reaction to produce a high conductivity material. Substantially pure reactants of the dopant, base polymer and ionic compound having a generally high purity are preferred, and more preferably a purity greater than 98%, most preferably even higher purity, such as LiOH: 99.6%, DDQ: > 98%, chloranil: 99 percent.

To further describe the utility of the solid ionically conductive polymer material and the versatility of the above-described method of synthesizing the solid ionically conductive polymer material of the present invention, several classes of solid ionically conductive polymer materials are described that can be used in and distinguished by multiple electrochemical applications:

lithium ion battery

In this aspect, the reaction or base polymer is characterized as semi-crystalline or fully crystalline and has a crystallinity value of 30% to 100%, preferably 50% to 100%. The base polymer has a glass transition temperature of greater than 80 ℃, preferably greater than 120 ℃, more preferably greater than 150 ℃, and most preferably greater than 200 ℃. The melting temperature of the base polymer is higher than 250 ℃, preferably higher than 280 ℃, more preferably higher than 320 ℃. The molecular weight of the monomer units of the base polymer of the present invention is in the range of 100 to 200gm/mol and can be greater than 200 gm/mol. Typical materials that can be used for the base polymer include liquid crystal polymers and polyphenylene sulfide, also known as PPS, or semi-crystalline polymers with a crystallinity index greater than 30%, preferably greater than 50%.

In this aspect, the dopant is an electron acceptor, such as DDQ, TCNE, chloranil, and sulfur trioxide (SO)₃). The electron acceptor may be "pre-mixed" with all other ingredients and extruded without post-processing, or a doping procedure such as gas phase doping may be used to add the electron acceptor to the composition after the other ingredients are mixed (e.g., in an extruder) and formed into a film.

Typical compounds for use in this aspect of the invention that include an ion source or "ionic compound" include, but are not limited to, Li₂O、LiOH、ZnO、TiO₂、Al₃O₂LiTFSI and other lithium ion compounds and combinations thereof. The ionic compound contains a suitable stable form of ions that are modified to release ions during synthesis of the solid ionically conductive polymer material.

Example 1

PPS and chloranil powders were mixed at a molar ratio of 4.2:1 (base polymer monomer to dopant ratio greater than 1: 1). The mixture is then heated in argon or air at elevated temperature (up to 350 ℃) and atmospheric pressure for 24 hours. A color change was observed confirming the generation of a charge transfer complex in the polymer-dopant reaction mixture. The reaction mixture is then reground to a small average particle size of 1-40 microns. LiTFSI is then mixed with the reaction mixture to produce a synthetic solid ionically conductive polymer material.

Example 2

Preparation of lithium cobaltate (LiCoO) containing the synthetic material from example 1₂) ("LCO") cathode. The cathode uses a high loading of 70 wt% LCO mixed with a solid ionically conductive polymer material and conductive carbon. Using lithium metal anodes, porous polypropylene separators and lithium ion power filters made from LiPF₆Standard Li-ion liquid electrolyte composed of salt and carbonate based solvent the cell was prepared. The cells were assembled in a dry glove box and tested cyclically.

The capacity of the LCO used in these cells by weight in grams is shown in fig. 1. It can be seen that the capacity is stable when charged to 4.3V and is consistent with the target of 0.5 equivalents of Li removed from the cathode during charging. The cell was also cycled to a higher charge voltage of 4.5V, which utilized a higher percentage of lithium from the cathode; and high capacity >140mAh/g was obtained. The slight decrease in capacity with cycle number observed in the 4.5V charge test is consistent with decomposition (i.e., instability) of the liquid electrolyte at this high voltage. Overall, the performance of LCO cathodes containing the material of the invention is advantageously comparable to slurry coated LCO cathodes.

Alkaline battery

The base polymer of the solid ionically conductive polymer material having hydroxide ion mobility is preferably a crystalline or semi-crystalline polymer, typically having a crystallinity value above 30% and up to and including 100%, preferably 50% to 100%. The base polymer of this aspect of the invention has a glass transition temperature of greater than 80 ℃, preferably greater than 120 ℃, more preferably greater than 150 ℃, and most preferably greater than 200 ℃. The melting temperature of the base polymer is higher than 250 ℃, preferably higher than 280 ℃, more preferably higher than 300 ℃.

The dopant of the solid ionically conductive polymer material having hydroxide ion mobility is an electron acceptor or an oxidant. Typical dopants used in this aspect of the invention are DDQ, chloranil, TCNE, SO₃Oxygen (including air), MnO₂And other metal oxides, and the like.

Involving migration of hydroxyl ionsCompounds of the ion source of the solid ionically conductive polymer material include salts, hydroxides, oxides, or other materials containing hydroxide ions or convertible into such materials, including but not limited to LiOH, NaOH, KOH, Li₂O、LiNO₃And the like.

Example 3

PPS polymer was mixed with the ionic compound LiOH monohydrate in a ratio of 67 to 33 wt%, respectively, and mixed using jet milling. DDQ dopant was added to the resulting mixture by gas phase doping in an amount of 1 mole DDQ/4.2 moles PPS monomer. The mixture is heat treated at 190-200 ℃ for 30 minutes under medium pressure (500-1000 PSI).

Composite MnO₂Cathode electrode

In the preparation of solid ionically conductive polymer materials-MnO₂In this aspect of the invention of the composite cathode, the base polymer may be a semi-crystalline or fully crystalline polymer having a crystallinity index greater than 30%, and may be selected from conjugated polymers or polymers that can be readily oxidized with the selected dopant. Non-limiting examples of base polymers useful in this aspect of the invention include PPS, PPO, PEEK, PPA, and the like.

In this aspect, the dopant is an electron acceptor or an oxidizing agent. Non-limiting examples of dopants are DDQ, chloranil, tetracyanoethylene (also known as TCNE), SO₃Ozone, oxygen, air, transition metal oxides (including MnO)₂) Or any suitable electron acceptor, etc.

In this aspect, the compound comprising the ion source is a salt, hydroxide, oxide, or other material containing hydroxide ions or convertible to such materials, including but not limited to LiOH, NaOH, KOH, Li₂O、LiNO₃And the like.

Example 4

PPS polymer and LiOH monohydrate were added together in a ratio of 67% to 33% by weight, respectively, and mixed using jet milling. Additional alkaline battery cathode components were additionally mixed: MnO₂、Bi₂O₃And conductive carbon. MnO₂50 to 80 wt% of Bi₂O₃0 to 30 wt%, a carbon black content of 3 to 25 wt%, and a polymer/LiOH content of 10 to 30 wt%.

The mixture is heated to synthesize an alkaline cell cathode comprising a solid ionically conductive polymer material that can be used in conventional zinc-manganese dioxide alkaline cells.

Example 5

An alkaline zinc-manganese dioxide cell was prepared by using the cathode of example 4 and a commercially available non-woven fabric separator (NKK), Zn foil anode and 6M LiOH solution as the electrolyte.

The cells were tested at 0.5mA/cm using the Bio-Logic VSP 15 test system²Is discharged under constant current conditions. Discovery of MnO₂The specific capacity of the electrode is 303mAh/g or close to theoretical 1 e-discharge.

Metal-air battery

In this aspect, a solid ionically conductive polymer material is used in a metal air cell and comprises a base polymer, a compound containing an ion source, and a dopant. The polymer may be selected from PPS, LCP, polypyrrole, polyaniline, and polysulfone, as well as other base polymers.

The dopant may be an electron acceptor or a compound containing a functional electron acceptor group capable of initiating an oxidation reaction with the polymer. Typical dopants are DDQ, chloranil, TCNE, SO₃Ozone and transition metal oxides, including MnO₂. The material comprising the ion source may be in the form of a salt, hydroxide, oxide, or other material containing hydroxide ions or that can be converted to such materials, including but not limited to LiOH, NaOH, KOH, Li₂O、LiNO₃And the like.

Example 6

The material synthesized in example 3 was used to prepare air electrodes by mixing solid ionically conductive polymer material with various carbons, specifically: timal SUPER C45 conductive carbon black (C45), TIMCAL SFG6 (synthetic graphite), a5303 carbon black, and natural vein graphite Nano 99(N99), from Ashbury. The carbon content varies between 15 and 25% by weight.

The cathode was punched to fit a 2032 coin cell. A zinc foil was used as the anode. The nonwoven membrane was impregnated with 40% KOH aqueous solution. Two holes were drilled in the top of the button facing the cathode. The cells were discharged at 0.5mA constant current, room temperature, by using an MTI coin cell tester.

Table 3 summarizes the cathode parameters and test results. The discharge curve is shown in fig. 2. The cell with the air cathode of this example using the material of the present invention exhibited the typical discharge behavior of a Zn-air cell without any conventional catalyst (transition metal based) added to the mixture. In addition to conducting hydroxide ions from the air cathode to the anode, the material also functions to catalyze the formation of hydroxide ions from oxygen present at the cathode surface. As shown in this example, the material of the present invention has a catalytic function.

Table 3.

#	Carbon (C)	C％	T(mil)	Weight (mg)	g/cc	OCV(V)	mAh
								1	C45	15％	23.3	102.7	0.553	1.2667	5.628
2	N99	5％	25.3	137.8	0.757	1.3343	4.742
								3	A5303	20％	21.5	116.8	0.755	1.3405	7.864
4	SFG6	25％	29.2	166.3	0.791	1.3185	6.539

Other ionic compounds

Many anions and cations can be conducted through the material of the present invention. The ionic compound used in the synthesis may be selected so that the desired diffusing ions are contained in the synthesis material.

Example 7

Material samples were made by mixing LCP polymer [ SRT900] ionic compounds in various ratios. DDQ was used as a dopant. The molar ratio of polymer monomer to dopant was 4.2: 1. The results are shown in Table 4. The mixture is heat treated at 190-200 ℃ for 30 minutes under medium pressure (500-1000 psi).

The sample was clamped between stainless steel electrodes and placed in a test fixture. The electrolyte conductivity was determined by recording the AC impedance in the range of 800KHz to 100Hz using a Bio-Logic VSP test system.

The results are shown in table 4 below. The observed high ionic conductivity indicates that the solid polymeric material can conduct a variety of ions, including lithium ion Li⁺Potassium ion K⁺Sodium ion Na⁺Calcium ion Ca²⁺Magnesium ion Mg²⁺Aluminum ion Al³⁺OH, OH^-And chloride ion Cl^-。

TABLE 4

Ion source	Ion source weight%	Conductivity (S/cm)
			Li₂O	33％	1.9E-04
Na₂O	33％	4.2E-05
			MgO	33％	6.3E-07
CaCl₂	33％	6.2E-03
			MgCl
₂	20％	8.0E-03
			AlCl₃	15％	2.4E-03
NaOH
		50％	1.3E-04
KOH
		50％	2.2E-04

Any ionic compound that can be dissociated by the dopant can be used, as long as the dissociated ion is desired in the applicable electrochemical application in which the material is used. Anions and cations originating from the ionic compound are thereby ionically conducted by the material. Ionic compounds include oxides, chlorides, hydroxides, and other salts. In this embodiment, the metal (or other cation) oxide produces a metal cation (or other cation) and hydroxide ions.

The ability to conduct a variety of ions other than lithium cations provides new applications for the materials of the present invention. Sodium-based and potassium-based energy storage systems are considered as alternatives to lithium ions, driven primarily by low cost and relatively abundant raw materials. Calcium, magnesium and aluminum conductivities are necessary for multivalent intercalation systems, potentially enabling an increase in energy density beyond the performance of lithium ion batteries. It is also possible to use this material to make power sources with metal anodes that are more stable, safer and less costly than lithium.

Example 8:

additional solid ionically conductive polymer materials prepared using the synthetic method of example 1, as well as their reactants and associated ionic conductivities (EIS method) are listed in table 5.

TABLE 5

Additional solid ionically conductive polymer materials prepared using the synthetic method of example 3, as well as their reactants and associated ionic conductivities (EIS method) are listed in table 6.

TABLE 6

The LCP's listed in Table 6 are derived from Solvay under the trade name Xydar and are species of LCP's having different melting temperatures.

Physical properties of solid ionically conductive polymer materials:

the physical properties of the solid ionically conductive polymer material may vary based on the reactants used. The specific ion mobility and anion diffusing ions and cation diffusing ions are derived from material synthesis; however, other physical properties do not appear to change significantly relative to the reactant polymers.

Example 9

Degree of crystallinity

The reactants PPS, DDQ, and LiOH from example 3 were used to compare the relative physical properties of the reactant polymers and the synthesized solid ionically conductive polymer material.

In the first step, the PPS reactant and LiOH monohydrate are mixed and analyzed by X-ray diffraction ("XRD"). In FIG. 3A, XRD of the amorphous polymer mixture shows a peak between 30 to 34 degrees corresponding to LiOH monohydrate. Otherwise, XRD showed that the polymer was amorphous and did not have any significant crystallinity.

The mixture was extruded and drawn into a film. The heating of the PPS polymer by the extruder in this step anneals (heating and maintaining at a suitable temperature below the melting point, and then slowly cooling) the amorphous PPS material while extruding the material into a film, thereby creating or increasing crystallinity. In fig. 3B, a distinct crystalline polymer peak is shown, which can also be used to quantify the crystallinity of the PPS material to about 60%. The peak of LiOH monohydrate remains.

The thin film mixture was then gas phase doped with DDQ dopant to produce the solid ion-conducting polymeric material of the present invention, and the corresponding XRD is shown in fig. 3C. A color change was observed during doping as the material turned black after doping. This color change indicates that: an ionic charge transfer complex is being formed, the polymer and dopant reactants have reacted in the presence of the ionic compound, and the material has been activated to become ionically conductive. The polymer peak remained, indicating that the crystallinity of the material remained at about 60% and thus unchanged. However, the LiOH monohydrate peak had disappeared and was not replaced by any other peak. It is concluded that the ionic compound has been dissociated into its constituent cations and anions, and that these ions are now part of the material structure.

Glass transition and melting point temperatures

Example 10

While there are many techniques for determining the melting temperature and Tg of bulk or film polymer samples, differential scanning calorimetry ("DSC," described in ASTM D7426 (2013)) provides a rapid test method for determining the change in specific heat capacity of a polymeric material. The glass transition temperature is expressed as a step change in specific heat capacity.

Referring to fig. 4, a DSC plot of the synthetic material from example 1 is shown. The melting point of the material [ PPS-chloranil-LiTFSI ] was obtained by DSC and was determined to be no different from the reactant polymer PPS: the Tm is about 300 ℃. The glass transition temperature Tg of the base polymer is 80-100 ℃, but no Tg inflection point appears in a DSC curve; it is believed that upon synthesis, the solid ionically conductive polymer material loses its distinct viscoelastic state in the PPS base polymer and the glassy state extends below a temperature range below the melting temperature of the material. It is believed that the slope at 130 ℃ in the figure is an artifact of ionic compounds (artifact).

Ionic conductivity

The ionic conductivity of the solid ionically conductive polymer material of the present invention was measured and compared against conventional electrolytes. The materials of the present invention were found to be ionically conductive at ambient conditions in the glassy state, while the reactant polymers were ionically insulating. Since the material is in the glassy state and there cannot be any associated segmental motion, diffusion of lithium cations and anions must be achieved by different ion conduction mechanisms in which segmental motion is not required.

Specifically, a film of the solid ionically conductive polymer material of the present invention as described in example 1 is extruded at a thickness of 0.0003 inches (7.6 microns) or more. The ionic surface conductivity of the film was measured by standard tests using AC Electrochemical Impedance Spectroscopy (EIS) known to those of ordinary skill in the art. A sample of the solid ionically conductive polymer material film was sandwiched between stainless steel blocking electrodes (blocking electrodes) and placed in a test fixture. The material ionic conductivity was determined by recording the AC impedance in the range of 800KHz to 100Hz using a Bio-Logic VSP test system. In-plane measurement by placing a thin film of material in a suitable jig using Bio-LogicAnd ion conductivity of the through plane (via plane). The through-plane conductivity was measured to be 3.1x 10^-4S/cm, in-plane conductivity 3.5x10^-4S/cm. These measurements are similar enough to consider the material as being ion conductivity isotropic.

A film having a thickness of about 150 microns was prepared using the material from example 1. The electron conductivity was measured directly by potentiostatic experiments. The membrane was placed between stainless steel blocking electrodes and a voltage of 0.25V was maintained between the electrodes. The current was measured at a current of 180 nanoamperes, yielding 2.3x10 at room temperature⁶Ω·cm²Electron conductivity of (2). The electron conductivity (area specific resistance) is low and is less than 1.0x10 at room temperature⁵Ω·cm²This is sufficient for the electrolyte.

Thermogravimetric analysis was performed on the material from example 1 to determine the moisture content of the material. After storing the material in a dry atmosphere glove box, thermogravimetric analysis was performed and showed that the material contained <5ppm water. Certain salts used as reactants for solid ionically conductive polymer materials (e.g., LiOH as an ionic compound) absorb atmospheric moisture and thus can render the material hydrophilic.

Example 12

The synthetic material of example 3 was tested for modulus. The Young's modulus of the electrolyte made of the specific solid polymer material ranges from 3.3 GPa to 4.0 GPa. However, the range of Young's moduli for the materials listed in this application is much larger, ranging from 3.0MPa to 4 GPa. The synthetic material remains thermoplastic and can be reformed using plastic processing techniques. The material of example 3 was heated above its melting point and then cooled. The material is then reformed into a thin film. Thus, the material exhibits a high modulus and thermoplasticity.

Comparative example 13

The results of the ionic conductivity measurements reported in example 1 are shown in fig. 5 and 6. The conductivity (Δ) of the solid ionically conductive polymer material film of the present invention was compared to the conductivity (□) of triflate PEO and the conductivity (O) of a liquid electrolyte (using Celgard membrane) composed of Li salt solute and ethylene carbonate-propylene carbonate "EC: PC" combination solvent.

Referring to fig. 5, measured conductivity as a function of temperature for a solid polymer ionically conductive material is shown. Also shown is the liquid electrolyte EC PC + LiPF with Celgard separator₆Measured ionic conductivity of the salt and measured ionic conductivity of the PEO-LiTFSI electrolyte. The conductivity of the solid ionically conductive polymer material is about 2.5 orders of magnitude higher than the PEO-LiTFSI electrolyte at room temperature and is comparable to the conductivity of a conventional liquid electrolyte/membrane system measured under similar conditions. The temperature dependence of the electrical conductivity of the solid ionically conducting polymer material does not show a sharp increase above its glass transition temperature, which is related to the chain mobility, as described by the temperature activated Vogel-Tamman-Fulcher behavior. Thus, segmental motion as an ion conduction mechanism in a polymer electrolyte material does not occur because the material exhibits significant ionic conductivity when in its glassy state. Furthermore, this indicates that the polymer material of the present invention has a similar level of ionic conductivity to the liquid electrolyte.

In fig. 6, the ionic conductivity of the solid ionically conductive polymer material is compared to the conductivity and temperature of a conventional liquid electrolyte, a comparative example of lithium phosphorus oxygen nitrogen "LIPON" and related DOE targets. Referring to fig. 5, the ionic conductivity of the solid ionically conductive polymer material is greater than 1x10 at room temperature (about 21 ℃)^-04S/cm, greater than 1x10 at about-30 ℃^-04S/cm (and greater than 1x 10)^-05S/cm) of greater than 1x10 at about 80 deg.c^-03S/cm。

Example 14

The ionic conductivity can be optimized by adjusting the material formulation. Figure 7 shows the improvement and optimization of ionic conductivity by adjusting the polymer material formulation (e.g., changing the base polymer, dopant, or ionic compound).

Rate of diffusion

In addition to ionic conductivity, diffusivity is an important intrinsic quality of any electrolyte and ion-conducting material.

Example 15

Diffusivity measurements were made on the material produced in example 3.

Basic NMR techniques are used to unambiguously identify Li + as a free-flowing ion in a solid ionically conductive polymer material. NMR is element specific (e.g., H, Li, C, F, P, and Co) and sensitive to small changes in local structure.

Specifically, the diffusivity of lithium and hydroxide ions was assessed by pulse gradient spin echo ("PGSE") lithium NMR methods. PGSE-NMR measurements were performed using a Varian-S Direct Drive 300(7.1T) spectrometer. The magic angle rotation technique is used to average chemical shift anisotropy and dipole interactions. Pulse gradient spin stimulated echo pulse sequences are used for self-diffusion (diffusivity) measurements. By separate use of¹H and⁷the Li nuclei measure the self-diffusion coefficients of cations and anions in each material sample. The self-diffusion coefficient determined by NMR is a measure of the randomly thermally induced translational motion, similar to brownian motion, with no external directional driving force. However, self-diffusion is strongly related to ion mobility and ion conductivity by the Nerst Einstein equation and is therefore an important measurement parameter in characterizing battery electrolytes. When having both ionic conductivity and diffusion data, the presence of ion pairs or higher aggregation effects that limit the performance of the electrolyte can be determined. These tests concluded that the solid polymeric ionically conductive material had a 5.7x10 characteristic at room temperature^-11m²Li of/s⁺Diffusivity such that it is higher than PEO/LiTFSI at 90 ℃ and higher than Li₁₀GeP₂S₁₂(measured at elevated temperatures) is at least one order of magnitude higher. Thus, the solid ionically conductive polymer material can be used as a new solid electrolyte with the unique ability to conduct multiple ions that can diffuse, migrate and provide sufficiently high ionic conductivity at room temperature for batteries and other applications.

OH at room temperature^-The diffusivity of the ion is 4.1x10^-11m²And s. Thus, the solid ionically conductive polymer material has an OH to solid^-Very high diffusion rates in the case of conductors. The corresponding cation transference number (defined in equation (1) below) was 0.58, which is also significantly higherAnd is different from the solid electrolyte of the prior art.

Example 16

For the material produced in example 1 [ PPS-DDQ-LiTFSI ]]Diffusivity measurements were made. Self-diffusion was measured using the technique set forth in example 15. Cation diffusivity of material D (at room temperature)⁷Li) is 0.23x10^-9m²S, anion diffusivity at room temperature D: (¹H) Is 0.45x10^-9m²/s。

To determine the degree of ionic association that would reduce the conductivity of the material, the relevant calculated conductivity was determined to be much greater than the measured conductivity by calculating the conductivity of the material via the Nernst-Einstein equation using the measured diffusion measurements. The difference averages at least one order of magnitude (or 10-fold). Therefore, it is considered that the conductivity can be increased by improving ion dissociation, and the calculated conductivity can be considered to be within the conductivity range.

The number of cation mobilities can be estimated from the diffusion coefficient data by equation (1):

t+～D+/(D++D-) (1)

wherein D + and D-refer to the diffusivity of Li cations and TFSI anions, respectively. From the above data, a t + value of about 0.7 was obtained in the solid ionically conductive polymer material, compared to a t + value of about 0.2 in the corresponding PEO electrolyte (the liquid carbonate electrolyte also had a t + value of about 0.2). The property of high cation transport number has a significant impact on cell performance. Ideally, a t + value of 1.0 is preferred, which means that the Li ions carry the full current. Anion mobility results in electrode polarization effects that may limit cell performance. In materials in which both ions are mobile, t + values above 0.5 are highly sought, although rarely obtained. The calculated migration number of 0.7 is not believed to have been observed in any liquid or PEO-based electrolyte. Although ionic association may affect the calculations, electrochemical results demonstrate transport numbers in the range of 0.65 to 0.75.

It is believed that t + depends on anion diffusion due to the higher lithium cation diffusion. Since cation diffusion is greater than the corresponding anion diffusion, the cation transport number is always higher than 0.5; and since the anion is mobile, the cation transference number must also be less than 1.0. It is believed that investigation of the lithium salt as an ionic compound will produce a cation transference number in this range of greater than 0.5 and less than 1.0. As a comparative example, some ceramics have been reported to have a high diffusion number, but such ceramics only transport a single ion, and thus the cation transference number decreases to 1.0 when D-is zero.

Although the migration number is calculated from NMR derived diffusivity measurements, alternative methods of calculating migration can be achieved by direct methods such as Bruce and Vincent methods. The Bruce and Vincent methods were used to calculate the transport number of solid ionically conductive polymer materials and were found to correlate well with NMR derived measurements.

Referring to fig. 8, the results of diffusion measurements performed on solid ionically conductive polymer materials over a larger temperature range are shown and compared to PEO containing LiTFSI as the ion source. The most important conclusions are: (i) li diffusion in solid polymer ionically conductive materials is almost two orders of magnitude higher than PEO LiTFSI polymer electrolytes at temperatures at which both compounds can be measured; (ii) the diffusion coefficient in solid polymeric ionically conductive materials is measurable at temperatures that drop to at least-45 ℃, which is a very low temperature for lithium diffusion measured in any solid material; specifically, the lithium ion diffusivity is greater than 1x10^-13m²And s. This excellent ion-conducting property of the solid ionically conductive polymer material at low temperatures exceeds the properties of typical liquid battery electrolytes. It is also noteworthy that the NMR spectrum temperature dependence indicates that the ion movement is independent of the polymer, since it is not dependent on polymer segmental motion, but rather achieves significant ion diffusion in its glassy state. Thus, it was demonstrated that there is a solid ionically conductive polymer material having a crystallinity of greater than 30%, a glassy state, and at least one cationic and at least one anionic diffusing ion, wherein at least one diffusing ion (in this aspect, both diffusing ions) is mobile in the glassy state.

Comparative example 17

The cation diffusivity of LiPON is taken from "Structural Characterization and Li dynamics in new Li₃PS₄ceramic ion conductor by solid-state and pulsed-field gradient NMR ", Malloy Govet, Steve Greenbaum, Chengdu Liang and Gayari Saju, Chemistry of Metals (2014). An experimental method similar to that set forth in examples 15 and 16 was used, and the diffusivity curves are shown in fig. 9. Determination of the cation diffusivity D (of) of LiPON at 100 ℃⁷Li) of 0.54x10^-12 m²And s. This diffusivity is about 80 times less than the diffusivity of the inventive material at ambient temperature (21 ℃).

Chemical structure of material

Experiments were conducted to determine information about the chemical structure of the solid ionically conductive polymer material.

Example 18

In this example, the materials synthesized in example 3 and their reactant components PPS, DDQ, and LiOH monohydrate were investigated.

The reactants or base polymer PPS were first analyzed: referring to FIG. 10, protons of PPS versus tetramethylsilane ("TMS") spectral standard ()¹H) The NMR spectrum is characterized by a single peak centered at 6.8 ppm. This is a clear indication of aromatic hydrogen, as expected from the polymer structure. Proton solid state MAS NMR spectra of PPS polymers were acquired on a 300MHz instrument. Asterisks indicate spin sidebands, and the inset shows expanded resolution.

Referring to FIG. 11, of a solid ionically conductive polymer material¹H NMR spectrum (top), where the spectrum is deconvoluted into OH-type protons (middle) and aromatic protons (bottom). The spectra confirmed aromatic hydrogen and hydroxyl. Proton solid state MAS NMR spectra of the material were acquired on a 500MHz instrument. Asterisks indicate spin sidebands, and the inset shows expanded resolution. The deconvolution of the spectra into OH "and base polymer protons is shown in the inset as an additional experimental spectrum. Since the NMR spectrum is quantitative (as long as care is taken not to saturate the signal), direct integration of the spectral peaks can give the proportion of nuclei in a particular phase. The results of this integration indicate that the material has more than one migratable OH ion per repeating aromatic group and contains about two LiOH molecules per polymer repeat unit (monomer), which isVery high ion concentration. The narrow OH signal shows high mobility of OH ions.

Additional structural information is available by carbon 13 solid state MAS NMR from-1% natural abundance¹³And C, realizing. Using cross-polarization (CP), whereby nearby protons interact with¹³The C nuclei resonate simultaneously, transferring the nuclear magnetization to the "rare" spins to increase detection sensitivity. In fig. 12, the PPS polymer spectra are depicted under two direct polarizations: all carbons involved in the signal (bottom), and only those carbons directly bonded to hydrogen involved in the CP (top). Thus, the difference spectrum (middle) corresponds to carbon bonded to sulfur.

See FIG. 13, which shows the electron acceptor compounds obtained on a 500MHz instrument by direct polarization¹³C spectra MAS NMR spectra with spectral assignments of the proposed electron acceptor DDQ. Since no hydrogen is present in the molecule, a spectrum is obtained under direct detection. Due to the very long spin-lattice relaxation time (which may exceed 1 minute), the signal-to-noise ratio is rather low. The assignments for the individual peaks are shown in fig. 3. Unlike the four peaks expected (corresponding to four chemically non-equivalent carbons), the appearance of six different peaks indicates the possible presence of isomers.

By direct polarisation of solid ionically conductive polymer material obtained on a 500MHz instrument¹³The C solid state MAS NMR spectrum is shown in fig. 14A, which indicates that the main peak (dominated by aromatic carbon) is shifted from PPS to the ion conducting material. The CP spectrum in the middle of the inset indicates that the PPS polymer strongly interacts with the OH groups of LiOH. The expanded scale spectra of the material and the DDQ electron acceptor are compared in fig. 14B, indicating that there is a chemical reaction in the material that obscures the original spectral features of the reactants.

This NMR analysis clearly shows that three different reactants have reacted to form the solid ionically conductive polymer material of the present invention. New materials have been formed which are not only mixtures of their constituent parts. There is a reaction between these three components and the solid polymeric ionically conductive material is the reaction product. In particular between the base polymer and the synthetic material¹³There was a shift in the C NMR peak. In addition to this, the present invention is,of hydrogen associated with OH¹H resonance and¹³the effect of simultaneous irradiation of the C resonance indicates that ions have been incorporated into the structure and therefore all three different components have reacted and are part of the new synthetic material.

Example 19

Quantification of the cation (e.g., lithium ion) concentration in the material of example 3 can be achieved by inserting the material into an inner coaxial tube and surrounding it with an external reference solution of a shifting agent complex, such as lithium Dysprosium polyphosphate. Referring to fig. 15, the shift in the resonance of lithium cations is caused by paramagnetic Dy, which can quantify lithium in a sample. In the measured sample, the lithium cation concentration was found to be about 3 moles/liter of material ([ Li ] 3 moles/liter). This large concentration of cations allows the solid ionically conductive material to have very high ionic conductivity at room temperature and over a wide temperature range.

Stability of materials

Liquid electrolytes and other polymer electrolytes can suffer from lithium stability problems. Their interaction with lithium results in a reaction between lithium and the electrolyte, which is detrimental to battery life. The electrolyte also needs to be compatible and non-reactive when used with other battery components, such as electrochemically active materials including intercalation materials, conductive additives, rheological agents, and other additives. In addition, at high voltages above 4.0 volts, typical electrolytes can simply decompose, which in turn leads to poor battery life. Thus, lithium "stability" is a requirement for polymer electrolytes. Specifically, the polymer electrolyte is unreactive and does not decompose when transporting lithium metal at voltages higher than 4.0V, 4.5V, and 5.0V.

Referring to fig. 16, a thin film battery structure 10 is shown. The anode comprises lithium metal 10 with an associated current collector (not shown) or a typical anode intercalation material for a lithium ion battery. If an intercalation material is selected, a solid ionically conductive polymer material is mixed therewith. Cathode 30 includes a cathode current collector (not shown) and an electrochemically active material or intercalation material. The solid ionically conductive polymer material is again mixed with the electrically conductive material. A thin film of solid ionically conductive polymer material serves as the separator/electrolyte 40 and is interposed between the anode and cathode.

Example 20

Solid ionically conductive polymer materials exhibit compatibility with various current lithium ion chemistries. Referring to fig. 17, the performance of a battery constructed as shown in fig. 16 and labeled with respect to the cathode electrochemically active material of interest is illustrated. Specifically, the battery is made of LiFePO₄、LiMn₂O₄And LiCoO₂A cathode and a lithium metal anode. A battery constructed with the material of the present invention mixed with the electrochemically active material in the cathode, wherein the material of the present invention is used as an electrolyte for introducing/discharging lithium ions into/from the anode and the cathode, exhibits appropriate discharge performance.

By using a solid polymer material as the electrolyte in all cell structures or in one of such structures (anode, cathode, separator and electrolyte), new performance levels can be achieved without the use of any liquid electrolyte. The material may be mixed with the electrochemically active material or the intercalation material in at least one of the electrodes. Ions required in the electrochemical reaction of the battery are conducted through the electrolyte. The material may be in the form of particles, slurry, film or other form suitable for use in a battery. As a thin film, the material can be inserted between electrodes or between an electrode and a current collector, placed to encapsulate the current collector or electrode, or placed anywhere where ionic conductivity is desired. As shown in fig. 16, all three major components of the battery can be made using solid polymer materials. In the aspect shown in fig. 16, the film-like electrode and the interposed separator or electrolyte may be separate structures, or may be attached to each other by thermal welding or other means of integrating thermoplastic films together.

Example 21

A cathode was prepared with LCO encapsulated by the material of example 1. The cathode was paired with a lithium metal anode and a thin film of material was interposed between the anode and cathode as depicted in the structure of fig. 16. The assembled battery is then charged and discharged through a plurality of cycles. Fig. 18 shows the resulting discharge curves for a number of cycles.

The charge-discharge curve shows almost no polarization and an efficiency of at least 99%. This result demonstrates the functionality of the polymer as an ion transport medium within the cathode and its ability to function as an electrolyte in a solid state battery. Also important is the voltage stability of the electrolyte when operated at voltages of four (4.0) volts to 4.3 volts and up to 5.0 volts, the stability with lithium metal, and the stability to transport lithium at rates in excess of 100mAh/g, particularly at least 133.5mAh/g lithium.

Example 22

The LiS cell was constructed to include a lithium metal anode and a sulfur cathode prepared in the construction depicted in fig. 16. The material of example 1 was used in the preparation of batteries. Traditionally, lithium-sulfur systems have attempted to overcome the problem of low cycle life caused by dissolution of the sulfidation reaction chemical intermediates in the liquid electrolyte typical of such cells.

The solid polymer material functions to realize a Li-S system by trapping the reaction intermediate in a solid system to restrict the dissolution of the reaction intermediate. The solid polymer material can transport lithium ions while preventing polysulfide ions (polysufide ion) from reaching the anode. The solid polymeric material limits the dissolution of sulfur particles and the transport of sulfur ions, thereby allowing more sulfur to participate in the reaction and increasing the capacity of the cathode. This improved capacity is shown in fig. 19 relative to a cell comprising a standard cathode containing only sulfur and carbon. It is also important to note that the data was obtained at room temperature. Solid polymer materials do not achieve the typical "indifferent diffusion" of liquid electrolytes and some common polymer electrolytes, but only allow diffusion of ions incorporated into the material during synthesis. Thus, the sulfide is not diffusible, but rather is non-ionically conductive much like any other ion other than the diffusing anion and diffusing cation. Thus, the material may act as an ion membrane, as it may be designed to enable ion migration of only selected ions.

Solid polymer electrolyte

As described, the solid ionically conductive polymer material serves as a solid electrolyte. As a solid electrolyte, it does not require a separator, but the solid electrolyte requires many of the same separator characteristics.

The separator is an ion permeable membrane placed between the anode and cathode of the cell. The primary function of the separator is to keep the two electrodes apart to prevent electrical shorting while also being able to transport the ionic charge carriers needed to close the circuit during the passage of current in the electrochemical cell. All batteries require such separation and ion transport operations.

The solid electrolyte must also be chemically stable to the electrode material in a strongly reactive environment when the battery is repeatedly fully charged and discharged. The separator should not degrade during normal and abnormal use of the battery. Of particular importance is voltage stability over the range of voltages encountered during charging and discharging.

The solid electrolyte must be thin to facilitate the energy density and power density of the battery. However, the solid electrolyte must work as a separator and must not be so thin as to be detrimental to mechanical strength and safety. The thickness should be consistent to support multiple charging cycles. The standard width is typically about 25.4 μm (1.0mil) and less than 30 μm. The thickness of the solid electrolyte can be measured by the T411 om-83 method of the technical Association of the pulp and paper industry. And it has been extruded at a thickness of 5 to 150 microns.

The polymer separator typically increases the resistance of the electrolyte four to five times and the deviation from uniform permeability produces a non-uniform current density distribution, which results in the formation of dendrites. Both of these problems can be eliminated by using a solid electrolyte that produces uniformity in ion conductivity and has isotropic ion conductivity.

The solid electrolyte must be strong enough to withstand the tension of any winding operation during cell assembly, or bending or other misuse of the cell. Mechanical strength is generally defined in terms of tensile strength in the machine (winding) direction and transverse direction, as defined by tear resistance and puncture strength. These parameters are defined in terms of young's modulus, which is the ratio of stress to strain. The young's modulus of the electrolyte made of a solid polymer material ranges from 3.0MPa to 4.0GPa, and it can be designed higher by using additives such as glass fiber or carbon fiber, if necessary.

The solid electrolyte must remain stable over a wide temperature range without curling or wrinkling and be placed perfectly flat. Although the ion transport properties of the solid electrolyte of the present invention vary with temperature, the structural integrity remains stable even under exposure to extreme heat, as will be described more fully below.

Thus, the solid ion-conductive polymer material satisfies the requirements of the separator and the solid polymer electrolyte by satisfying the requirements listed above. Specifically, the solid polymer electrolyte has the following characteristics: young's modulus greater than 3.0MPa, thickness less than 50 microns, isotropic ionic conductivity, diffusivity of various ions at temperatures as low as-45 ℃, stability (non-reactive) with lithium metal, electrochemically active materials and conductive additives at high voltages, thermoplasticity and moldability.

Example 23

The flammability of the solid polymeric material was tested according to the parameters of the UL94-V0 flammability test. It was found that the solid polymeric material was virtually non-flammable, self-extinguishing within two seconds. In order to be considered nonflammable according to the UL94-V0 standard, the material needs to self-extinguish in less than ten seconds.

The present application and this detailed description herein contain the entire specification of the following applications, including the claims, abstract and drawings: U.S. provisional patent application Ser. No.62/158,841, filed 5, 8/2015; U.S. patent application Ser. No.14/559,430, filed on 3/12/2014; U.S. provisional patent application Ser. No.61/911,049 filed on 3/12/2013; Ser.No.13/861,170, filed on 11/4/2013; and U.S. provisional patent application Ser. No.61/622,705, filed 4/11/2012.

Although the present invention has been described in detail with respect to certain preferred embodiments thereof, those skilled in the art will appreciate that many modifications and variations are possible without departing from the spirit of the invention. Accordingly, it is applicants' intent to be limited only by the scope of the appended claims, and not by the details and instrumentalities describing the embodiments shown herein.

It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.

Claims

1. A solid ionically conductive polymer material having:

a crystallinity of greater than 30%;

a melting temperature;

a glassy state;

greater than 1x10^-4S/cm of ionic conductivity at room temperature; and

at least one cationic diffusing ion and at least one anionic diffusing ion, wherein at least one diffusing ion is mobile in the glassy state;

wherein the material is prepared by one of the following methods:

i) mixing the base polymer and the ionic compound, then mixing and heating the dopant with the polymer-ionic compound mixture, wherein the mixture is heated during the second mixing step, or

ii) first mixing the base polymer and the dopant and then heating, wherein this heating step is applied after or during mixing and produces a color change indicating the formation of the charge transfer complex and the reaction between the base polymer and the dopant, and then mixing an ionic compound into the reacted polymer dopant material to complete the formation of the solid ionically conductive polymer material;

wherein the dopant that can be used as a reactant in the synthesis of the solid ionically conducting polymer material is an electron acceptor or an oxidant;

wherein the base polymer is selected from the group consisting of polyphenylene sulfide (PPS), polyphenylene oxide (PPO), Liquid Crystal Polymer (LCP), Polyetheretherketone (PEEK), polyphthalamide (PPA), polypyrrole, polyaniline and polysulfone, including monomers of the listed polymersCopolymers of (a) and mixtures of these polymers, polyaniline-polyphenylamine [ C ]₆H₄NH]_nPoly (p-phenylene terephthalamide) [ -CO-C₆H₄-CO-NH-C₆H₄-NH-]_nPolyvinylidene fluoride (PVDF), Polyacrylonitrile (PAN), Polytetrafluoroethylene (PTFE), and Polyethylene (PE);

wherein the ionic compound is selected from Li₂O、LiOH、ZnO、TiO₂、Al₂O₃、NaOH、KOH、LiNO₃、Na₂O、MgO、CaCl₂、MgCl₂、AlCl₃LiTFSI (lithium bistrifluoromethanesulfonimide), LiFSI (lithium bis (fluorosulfonyl) imide), and lithium bis (oxalato) borate (LiB (C)₂O₄)₂LiBOB), other lithium salts, and combinations thereof;

wherein the dopant is selected from 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ) (C)₈Cl₂N₂O₂) Tetrachloro-1, 4-benzoquinone (chloranil) (C)₆Cl₄O₂) Tetracyanoethylene (TCNE) (C)₆N₄) Sulfur trioxide (SO)₃) Ozone (ozone or O)₃) Oxygen (O)₂) Air, transition metal oxides, and combinations thereof.

2. The material of claim 1, wherein the material has a melting temperature greater than 250 ℃.

3. The material of claim 1, wherein the glassy state exists at a temperature below the melting temperature of the material.

4. The material of claim 1, wherein the material further comprises a plurality of charge transfer complexes, wherein each of the plurality of charge transfer complexes is formed by a reaction of the base polymer and an electron acceptor.

5. The material of claim 1, wherein the material is thermoplastic.

6. The material of claim 1, wherein the cation diffusing ions comprise lithium.

7. The material of claim 1, wherein the material has a cation transference number greater than 0.5 and less than 1.0.

8. The material of claim 6, wherein the concentration of lithium is greater than 3 moles of lithium per liter of material.

9. The material of claim 1, wherein the material comprises a plurality of charge transfer complexes and a plurality of monomers, wherein each charge transfer complex is located on a monomer, and wherein each monomer comprises an aromatic ring structure or a heterocyclic ring structure located in the backbone of the monomer.

10. The material of claim 9, wherein the material further comprises a heteroatom incorporated into the ring structure or located on the polymer backbone adjacent to the ring structure.

11. The material of claim 1, wherein the ionic conductivity of the material is isotropic.

12. The material of claim 1 having an ionic conductivity greater than 1x10 at 80 ℃^-3S/cm。

13. The material of claim 1 having an ionic conductivity greater than 1x10 at-40 ℃^-5S/cm。

14. The material of claim 1, wherein the material exhibits UL 94V-0 flame retardancy.

15. The material of claim 1, wherein the material is unreactive when mixed with a second material, wherein the second material is selected from the group consisting of electrochemically active materials, electrically conductive materials, rheology modifying materials, and stabilizing materials.

16. The material of claim 1, wherein the material is in the form of a film.

17. The material of claim 1, wherein the material has a young's modulus equal to or greater than 3.0 MPa.

18. The material of claim 1, wherein the transition metal oxide comprises MnO₂。