CN107681193A - Solid electrolyte and preparation method thereof, battery - Google Patents

Abstract

A kind of solid electrolyte and preparation method thereof, battery.The solid electrolyte includes：Matrix, lithium salts and PEO (PEO) additive.The solid electrolyte can be used for preparing solid state battery, have the characteristics that flexible, nonflammable, intensity is high, ionic mobility is high.

Description

Solid electrolyte, preparation method thereof, and battery

technical field

Embodiments of the present invention relate to a solid electrolyte, a preparation method thereof, and a battery.

Background technique

As an important energy storage device, lithium-ion battery has undergone many technological innovations. Because of its high energy density, light weight and long life, it is widely used in various fields such as ordinary electronic devices and electric vehicles.

In recent years, flexible electronic devices with the characteristics of bendable, foldable, wearable, and portable have become the development trend of a new generation of electronic devices. However, during the development of flexible electronic devices, the lithium-ion batteries used to provide energy cannot match the special structure of flexible electronic devices, which has become a fatal factor that curbs the development of flexible electronic devices. Therefore, the development of an ultra-thin, portable, flexible all-solid-state lithium-ion battery that can be used to follow up and meet the needs of a new generation of flexible electronic devices has become a key project of current research.

Contents of the invention

At least one embodiment of the present invention provides a solid electrolyte, including: a matrix, a lithium salt, and a polyethylene oxide (PEO) additive.

For example, in the solid electrolyte, the matrix is ethoxytrimethylolpropane triacrylate (ETPTA).

For example, in the solid electrolyte, the lithium salt is lithium bistrifluoromethanesulfonimide (LiTFSI).

For example, the solid electrolyte may also include inorganic nanoparticles.

For example, in the solid electrolyte, the nanoparticles are Al ₂ O ₃ nanoparticles or TiO ₂ nanoparticles.

For example, the solid electrolyte may further include an ultraviolet polymerization initiator.

For example, in the solid electrolyte, the ultraviolet polymerization initiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone (HMPP).

For example, in the solid electrolyte, the mass ratio of the matrix: the polyethylene oxide: the nanoparticles is 12:(0-8):20.

At least one embodiment of the present invention provides a battery, including a positive electrode active material, a negative electrode active material, and the above-mentioned solid electrolyte between the positive electrode active material and the negative electrode active material.

For example, in the battery, the positive electrode active material and the negative electrode active material are positive electrode active materials and negative electrode active materials for lithium ion batteries.

At least one embodiment of the present invention provides a method for preparing a solid electrolyte, comprising: mixing a matrix, a lithium salt solution, and an additive polyethylene oxide (PEO) to form a solid electrolyte precursor, and curing to form the solid electrolyte.

For example, in the preparation method of the solid electrolyte, the matrix is ethoxytrimethylolpropane triacrylate (ETPTA).

For example, in the preparation method of the solid electrolyte, the lithium salt solution is lithium bistrifluoromethanesulfonimide (LiTFSI) solution.

For example, in the preparation method of the solid electrolyte, the lithium bistrifluoromethanesulfonimide is dissolved in an anhydrous organic solvent to form a 0.6-1.2 mol/L lithium salt solution, and then mixed with the substrate and The additive polyethylene oxide (PEO) is mixed to form a mixed slurry.

For example, in the preparation method of the solid electrolyte, the anhydrous organic solvent is ethanedinitrile or butanedinitrile.

For example, in the preparation method of the solid electrolyte, the matrix is ethoxytrimethylolpropane triacrylate (ETPTA), the lithium salt solution: ethoxytrimethylolpropane triacrylate: polycyclic The mass ratio of oxyethane is (60-70):12:(0-8).

For example, the preparation method of the solid electrolyte further includes: adding inorganic nanoparticles to the mixed slurry, and the inorganic nanoparticles are Al ₂ O ₃ nanoparticles or TiO ₂ nanoparticles.

For example, in the preparation method of the solid electrolyte, the lithium salt solution: ethoxytrimethylolpropane triacrylate: polyethylene oxide: the mass ratio of nanoparticles is (60-70):12:( 0-8): 20.

For example, the preparation method of the solid electrolyte further includes adding an ultraviolet polymerization initiator into the mixed slurry, and irradiating with ultraviolet light to cure the mixed slurry.

For example, in the preparation method of the solid electrolyte, the ultraviolet polymerization initiator is 2-hydroxyl-2-methyl-1-phenyl-1-propanone, and the 2-hydroxyl-2-methyl-1-benzene The mass percentage of base-1-propanone added is 1-5%.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description only relate to some embodiments of the present invention, rather than limiting the present invention .

Fig. 1 is a flow chart of the preparation of a solid electrolyte provided by an embodiment of the present invention;

2A and 2B are schematic structural views of a battery provided by an embodiment of the present invention;

Fig. 3 is a picture of a bending test of a battery provided by an embodiment of the present invention;

4A and 4B are schematic structural views of a battery provided by another embodiment of the present invention.

Reference signs:

101-substrate; 102-conductive current collecting layer; 1021-first conductive current collecting layer; 1022-second conductive current collecting layer; 103-negative active layer; 104-electrolyte layer; 105-positive active layer; 106-encapsulation layer 201-substrate; 202-conductive current collecting layer; 2021-first conductive current collecting layer; 2022-second conductive current collecting layer; 203-negative active layer; 204-electrolyte layer; 205-positive active layer; 206-package Floor.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the usual meanings understood by those skilled in the art to which the present invention belongs. "First", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Comprising" or "comprising" and similar words mean that the elements or items appearing before the word include the elements or items listed after the word and their equivalents, without excluding other elements or items. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right" and so on are only used to indicate the relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

The solid electrolyte used in the existing batteries used in flexible electronic devices often lacks strength. After repeated bending, the solid electrolyte is easily damaged, resulting in a short circuit between the positive and negative electrodes; moreover, during the preparation process of the solid electrolyte, its surface is brushed. In the case of positive electrode active material slurry or negative electrode active material slurry, due to capillary force, the organic solution contained in the positive and negative electrode active material slurry is easily absorbed into the pores in the solid electrolyte, thereby causing local deformation and damage of the battery; and , There is a difference between the solid electrolyte material and the adjacent positive or negative active layer material, so a heterojunction will be formed, which will increase the contact resistance between the solid electrolyte and the positive or negative active layer interface.

At least one embodiment of the present invention provides a solid electrolyte, including: a matrix, a lithium salt, and a polyethylene oxide (PEO) additive.

At least one embodiment of the present invention provides a battery, including a positive electrode active material, a negative electrode active material, and the above-mentioned solid electrolyte between the positive electrode active material and the negative electrode active material.

At least one embodiment of the present invention provides a method for preparing a solid electrolyte, comprising: mixing a matrix, a lithium salt solution, and an additive polyethylene oxide (PEO) to form a solid electrolyte precursor, and curing to form the solid electrolyte.

The solid electrolyte, its preparation method, and battery of the present invention will be described below through several specific examples.

Embodiment one

This embodiment provides a solid electrolyte, which is used, for example, in a lithium-ion battery. The solid electrolyte includes: matrix, lithium salt and polyethylene oxide (PEO) additive. For example, the matrix material can be ethoxytrimethylolpropane triacrylate (ETPTA), and the lithium salt can be lithium bistrifluoromethanesulfonimide (LiTFSI). Lithium bistrifluoromethanesulfonylimide is not easily decomposed by moisture, and can also be synthesized in an air atmosphere to reduce manufacturing costs; polyethylene oxide (PEO) as an additive can prevent the solid electrolyte from being deformed due to inhalation of organic solutions, and at the same time The PEO additive can also reduce the interfacial impedance between the positive electrode active layer and the negative electrode active layer with PEO as the binder and the solid electrolyte, increase the conductivity of the solid electrolyte, and improve the performance of the lithium ion battery using the solid electrolyte.

For example, in one example, the solid electrolyte may also include a certain amount of inorganic nanoparticles, such as Al ₂ O ₃ nanoparticles or TiO ₂ nanoparticles, etc., and the particle diameter of these inorganic nanoparticles is, for example, not greater than 30 nanometers, such as a particle diameter of 10nm. The addition of inorganic nanoparticles can enhance the strength of the thin film prepared by the solid electrolyte, so that the battery made of it will not cause accidents such as short circuit of the positive and negative electrodes due to the fragile solid electrolyte after being bent many times.

In this embodiment, the solid electrolyte can also include 2-hydroxy-2-methyl-1-phenyl-1-propanone (HMPP) as an ultraviolet polymerization initiator, so that the solid electrolyte can form fine-pored The semi-penetrating structure of the solid film ensures that the solid electrolyte has a high mobility of lithium ions and improves the solidification efficiency of the solid electrolyte during the preparation process.

Performance tests were performed on the solid electrolyte containing PEO additive and the solid electrolyte not containing PEO additive provided in this example, for example, observing the state after the surface layer of the two solid electrolytes was dropped into anhydrous acetonitrile. The test results show that the solid electrolyte is deformed after dropping anhydrous acetonitrile on the surface layer of the solid electrolyte without PEO additives, and the solid electrolyte does not deform when the surface layer of the solid electrolyte containing PEO additives is dripped with anhydrous acetonitrile; anhydrous acetonitrile volatilizes and dries After that, the deformation of the solid electrolyte without the PEO additive could not be recovered, while the solid electrolyte with the PEO additive was still not deformed, maintaining the original appearance of the solid electrolyte. It can be seen that PEO as an additive effectively prevents the deformation of the solid electrolyte due to the inhalation of the organic solution.

Embodiment two

This embodiment provides a method for preparing a solid electrolyte, as shown in Figure 1, the preparation method includes:

S101: Prepare a solid electrolyte precursor solution.

In this embodiment, the solid electrolyte precursor solution may include a matrix, a lithium salt solution, and a polyethylene oxide (PEO) additive. For example, ethoxytrimethylolpropane triacrylate (ETPTA) can be selected as the matrix material, and lithium bistrifluoromethanesulfonimide (LiTFSI) solution can be selected as the lithium salt solution. First, lithium bistrifluoromethanesulfonimide is dissolved in a high-boiling organic solvent capable of UV cross-linking. For example, ethanedinitrile or succinonitrile solvent can be selected as the organic solvent. The organic solvent is a non-flammable polymer, which can improve its safety and reliability when used to prepare a solid electrolyte. Dissolve lithium bistrifluoromethanesulfonylimide into ethanedinitrile or succinonitrile solvent to form a 0.6-1.2mol/L lithium salt solution, for example, a 1mol/L lithium salt solution; during the preparation process, The lithium salt solution may be heated, for example, at 60 degrees Celsius to increase the dissolution rate of the lithium salt. Then, the above lithium salt solution is mixed with the matrix ethoxytrimethylolpropane triacrylate and the additive polyethylene oxide to form a mixed solution. In this embodiment, the lithium salt solution: matrix ethoxytrimethylolpropane triacrylate: the mass ratio of polyethylene oxide additive can be (60-70): 12: (0-8), for example 65 :12:1 or 67:12:3 etc.

In another example of this embodiment, a certain amount of nano-powder, such as Al ₂ O ₃ nano-powder with a particle size of 10 nm, may also be added to the above mixed slurry. The mass ratio of lithium salt solution: matrix ethoxytrimethylolpropane triacrylate: polyethylene oxide additive: nanoparticles can be (60-70):12:(0-8):20. Fully stir the mixed slurry, for example, ultrasonic dispersion treatment can be carried out, for example, ultrasonic dispersion at 100 Hz for 10 minutes to ensure the uniformity of the mixed slurry, and then the mixed slurry can be vacuum-dried, for example, it can be placed in a vacuum drying oven at 80 degrees Celsius Drying in medium for 24 hours finally forms a solid electrolyte precursor.

S102: film forming treatment.

The above-mentioned dried solid electrolyte precursor solution is subjected to impurity removal treatment, for example, the solid electrolyte precursor solution can be put into a glove box, the light source is shielded, the solid electrolyte precursor solution is stirred at 60 degrees Celsius, and a certain amount of ultraviolet polymerization initiator is added therein. For example, 2-hydroxyl-2-methyl-1-phenyl-1-propanone (HMPP) can be added at a mass percentage of (1-5)% as an ultraviolet polymerization initiator; HMPP can form a solid electrolyte under ultraviolet irradiation The fine semi-penetrating structure of the pores can ensure that the solid electrolyte has a high mobility of lithium ions and improve the solidification efficiency of the solid electrolyte during the preparation process. Scrape-coat the prepared solid electrolyte precursor solution on the surface of the desired substrate; wherein, the substrate can be preheated in advance, for example, heat treatment at 60 degrees Celsius; then scrape-coat the solid electrolyte precursor solution The material is placed in a homogenizer for film removal treatment, for example, placed in the suction cup of the homogenizer, and the film is thrown at a speed of 1000rpm for 1 minute, and then the substrate is placed on a heating plate such as 60 degrees Celsius, and irradiated by ultraviolet rays, such as using A 250W ultraviolet lamp is irradiated for 30 seconds at a height of about 5 cm from the substrate, and then the solid electrolyte precursor solution is cured to obtain a solid electrolyte membrane.

It should be noted that for the various raw materials used in this embodiment, such as ethoxytrimethylolpropane triacrylate, lithium bistrifluoromethanesulfonimide, polyethylene oxide, etc., can also be prepared in the early stage. Pretreatment; for example, ethoxytrimethylolpropane triacrylate, HMPP, lithium bistrifluoromethanesulfonimide, polyethylene oxide, and ethanedinitrile solvents are dried at 80 degrees Celsius in a vacuum oven 24 hours; dry the Al ₂ O ₃ nanometer powder in a vacuum drying oven at 120 degrees Celsius for 24 hours, etc.; this process can be adjusted according to the actual conditions such as the specific state of the raw material, which is not limited in this embodiment.

In this embodiment, when the mass ratio of lithium salt solution: matrix ethoxytrimethylolpropane triacrylate: polyethylene oxide additive is 68:12:1 (hereinafter referred to as Example 1), the finally obtained The thickness of the solid electrolyte membrane is about 70 microns, and the ionic conductivity of the solid electrolyte is about 1.5×10 ^-3 S/cm at room temperature. In this example, the method for testing the ionic conductivity is as follows: in an argon protective glove box, sandwich the prepared solid electrolyte between two stainless steel gaskets and press it into a button battery, and then place it in an oven at a temperature of 60 degrees Celsius The medium was kept warm for 2 hours, so that the solid electrolyte was in good contact with the stainless steel electrode, and then the electrochemical workstation was used to test the AC impedance spectrum of the button battery containing the solid electrolyte, and the frequency was set at 0.01 to 10 ⁶ Hz during the test. Finally, the ionic conductivity can be calculated by using the formula σ=l/SR, where σ represents the ionic conductivity, l represents the thickness of the solid electrolyte film, S represents the surface area of the solid electrolyte film, and R represents the test results in the AC impedance spectrum the impedance value.

In this embodiment, when the mass ratio of lithium salt solution: substrate ethoxytrimethylolpropane triacrylate: polyethylene oxide additive is 68:12:2, the substrate is placed in a uniform The suction cup of the glue machine is at the speed of 3000rpm and the film is thrown for 1 minute. Under the experimental conditions of other conditions unchanged (hereinafter referred to as Example 2), the thickness of the final solid electrolyte film is about 80 microns, and the lithium ion migration of the solid electrolyte is obtained through testing. The rate is about 1.8×10 ^-3 S/cm at normal temperature.

In this example, when the mass ratio of lithium salt solution: matrix ethoxytrimethylolpropane triacrylate: polyethylene oxide additive is 68:12:4, the base material is placed in a uniform glue The suction cup of the machine is still at the rotating speed of 1000rpm and the film is thrown for 1 minute. When the other conditions are constant (hereinafter referred to as Example 3), the thickness of the solid electrolyte film finally obtained is about 80 microns, and the lithium ion of the solid electrolyte is obtained after testing. The mobility is about 2.5×10 ^-3 S/cm at normal temperature. Compared with the above example, in this example, the addition ratio of the polyethylene oxide additive is increased, while the addition amount of the lithium salt solution is reduced, which will facilitate the brushing of the positive and negative electrolytic slurry with high organic solution content on the surface of the solid electrolyte.

In this example, when the mass ratio of lithium salt solution: matrix ethoxytrimethylolpropane triacrylate: polyethylene oxide additive is 68:12:8, the base material is placed in a uniform glue When the suction cup of the machine is at a speed of 3000rpm and the film is thrown for 1 minute, and other conditions are kept constant (hereinafter referred to as Example 4), the thickness of the final solid electrolyte film is about 80 microns, and the lithium ion migration of the solid electrolyte is obtained through testing. The rate is about 1.6×10 ^-3 S/cm at normal temperature.

In this embodiment, when nanoparticles are added to the solid electrolyte (hereinafter referred to as Example ₅ ), for example, _Al2O3 nanoparticles are added and the lithium salt solution in the solid electrolyte: matrix ethoxytrimethylolpropane triacrylate: When the mass ratio of the polyethylene oxide additive is 68:12:4::20, the lithium ion mobility of the obtained solid electrolyte is about 4.8×10 ⁻⁴ S/cm at room temperature. Although the lithium ion mobility of the solid electrolyte in this example is slightly lower than that of the solid electrolyte without nanoparticles, the addition of nanoparticles will increase the strength of the solid electrolyte, and the increase in the strength of the solid electrolyte can be to a certain extent In order to avoid the short circuit phenomenon caused by lithium dendrites piercing the solid electrolyte membrane during long-term use of the battery.

It can be seen from Examples 1, 2, 3, 4, and 5 that when different raw material ratios and experimental conditions are selected, the properties of the obtained solid electrolytes are slightly different, so the appropriate one can be selected according to product requirements or production conditions. Raw material ratio and experimental parameters.

It should be noted that the raw material ratio and production process parameters of the solid electrolyte in this embodiment can also adopt other reasonable values, and the properties of the finally obtained solid electrolyte can be combined with the raw material ratio and production process selected in the above embodiment A reasonable inference can be made by comparing the parameters with the various performance indexes of the obtained solid electrolyte, which will not be described in detail in this embodiment.

Embodiment three

As shown in Fig. 2A and Fig. 2B, this embodiment provides a battery, which includes a positive electrode active material, a negative electrode active material, and a solid electrolyte provided by an embodiment of the present invention, and the solid electrolyte is located between the positive electrode active material and the negative electrode active material . The battery can be, for example, a lithium ion battery, so the above-mentioned positive electrode active material and negative electrode active material are positive electrode active materials and negative electrode active materials for lithium ion batteries.

For example, the battery includes: a first conductive current collecting layer 1021 and a second conductive current collecting layer 1022 formed on a substrate 101 , a first electrode material layer, a second electrode material layer and an electrolyte layer. The first conductive current collecting layer 1021 and the second conductive current collecting layer 1022 are insulated from each other; the first electrode material layer is disposed on the first conductive current collecting layer 1021; the second electrode material layer is disposed on the second conductive current collecting layer 1022; The electrolyte layer 104 is disposed between the first electrode material layer and the second electrode material layer.

In this embodiment, the first conductive current collecting layer 1021 and the second conductive current collecting layer 1022 can have the same material, for example, they can be copper or copper alloy film, aluminum or aluminum alloy film, nickel or nickel alloy film, or transparent Conductive oxide films, such as indium tin oxide (ITO), etc. In this embodiment, the first conductive current collecting layer 1021 and the second conductive current collecting layer 1022 are formed on the same layer of the substrate 101 , so the manufacturing process and assembly process of the battery can be simplified.

In this embodiment, the first electrode material layer may be the negative electrode active layer 103 . The negative active layer 103 may include, for example, a negative active material, a conductive agent, additives, etc. that are uniformly mixed. In one example, the negative electrode active layer includes a negative electrode active material, a conductive agent, polyethylene oxide (PEO), wherein the negative electrode active material can be lithium titanate, lithium manganese titanate or other suitable negative electrode active materials; the conductive agent It can be poly 3,4-ethylenedioxythiophene/polystyrene sulfonate (PEDOT:PSS), and PEDOT:PSS not only functions as a conductive agent, but also as a binder; polyethylene oxide (PEO), as an additive, has strong electrical conductivity and bonding ability with the electrode active material, which can ensure that the negative electrode active material can be coated and attached to the plastic substrate with hydrophobic characteristics or the conductive current collector adjacent to it. The addition of polyethylene oxide on the surface of the negative electrode active layer 103 can also enhance the lithium ion mobility and electrical conductivity of the negative electrode active layer 103 . In this embodiment, the mass ratio of negative electrode active material, conductive agent, and polyethylene oxide can be (8:1:1)-(12:1:0.5), for example, negative electrode active material, conductive agent, polyethylene oxide The mass ratio of ethane may be, for example, 12:1:1, for example, 9:1:0.5.

In this embodiment, the second electrode material layer may be the positive electrode active layer 105 . The positive active layer 105 may include, for example, a uniformly mixed positive active material, a conductive agent, an additive agent, and the like. For example, the positive active layer includes a positive active material, a conductive agent, polyethylene oxide (PEO), etc., wherein the positive active material can be lithium cobaltate, lithium nickelate, lithium iron phosphate, lithium cobalt phosphate, lithium manganate Or other suitable positive electrode active materials; the conductive agent can also be poly 3,4-ethylenedioxythiophene/polystyrene sulfonate (PEDOT:PSS), PEDOT:PSS has the effect of conductive agent, and can also play a role in bonding The function of the agent; as an additive, polyethylene oxide (PEO) has strong electrical conductivity and bonding ability with the electrode active material, and can also enhance the lithium ion migration ability and electrical conductivity of the positive electrode active layer 105. In this embodiment, the mass ratio of the positive electrode active material, conductive agent, and polyethylene oxide can be (8:1:1)-(12:1:0.5), for example, the negative electrode active material, conductive agent, polyethylene oxide The mass ratio of ethane may be, for example, 10:1:1, for example, 11:1:0.5.

In this embodiment, when the lithium-ion battery requires high adhesion to the negative electrode active layer 103 or the positive electrode active layer 105, the electrode material composition can also include a binder, for example, the binder can be polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) or other suitable binders, the specific type of which is not limited here.

It should be noted that in this embodiment, the first electrode material layer can also be a positive electrode active layer, while the second electrode material layer is a negative electrode active layer, and the specific polarities of the first electrode material layer and the second electrode material layer are set here No limit.

In this embodiment, the electrolyte layer 104 is disposed on and in contact with the first electrode material layer, that is, the negative electrode active layer 103 ; the second electrode material, that is, the positive electrode active layer 105 is disposed on and in contact with the electrolyte layer 104 . In this embodiment, the electrolyte layer 104 can be a solid electrolyte; for example, the electrolyte layer 104 can be the solid electrolyte provided in any of the above embodiments, the solid electrolyte is flexible, non-flammable, and also has the characteristics of high strength and high mobility of lithium ions. . For example, the solid electrolyte may include a matrix, a lithium salt, additives, and the like. For example, the matrix can be selected from ethoxytrimethylolpropane triacrylate (ETPTA), the lithium salt can be selected from lithium bistrifluoromethanesulfonimide (LiTFSI), and the additive can be selected from polyethylene oxide (PEO); The additive can reduce or avoid the risk of bending fracture of the solid electrolyte, and improve the lithium migration number and ion conductivity of the solid electrolyte. In the above-mentioned example of using PEO as the binder in the active layer, the PEO additive can also reduce the interface impedance between the positive electrode active layer or the negative electrode active layer with PEO as the binder and the solid electrolyte, and improve the obtained lithium ions. battery performance. In one example, the solid electrolyte can also include, for example, 2-hydroxy-2-methyl-1-phenyl-1-propanone (HMPP) as an ultraviolet polymerization initiator, so that the solid electrolyte can form fine pores under ultraviolet irradiation. The semi-penetrating structure of the solid film ensures that the solid electrolyte has a high mobility of lithium ions and improves the solidification efficiency of the solid electrolyte during the preparation process.

For example, in another example, the solid electrolyte may also include an appropriate amount of inorganic nanopowder, such as Al ₂ O ₃ nanopowder with a particle size of 8-15nm (for example, 10nm) to enhance the strength of the solid electrolyte, making it possible to make The battery will not be short-circuited by the positive and negative electrodes due to the damage of the solid electrolyte after being bent many times. Moreover, the solid electrolyte is flexible, non-flammable, and also has the characteristics of high strength and high ion mobility. In this embodiment, the solid electrolyte not only functions as an electrolyte, but also functions as a separator, that is, it conducts ions between the positive and negative electrodes while preventing the conduction of electrons. The amount of inorganic nano-powder added is based on improving its mechanical properties without affecting its electrical properties.

In this embodiment, the substrate 101 can be a plastic substrate, for example, its material can be a common plastic material, such as polyethylene terephthalate film (PET); the substrate 101 can also be selected from polyethylene naphthalene with high temperature resistance. Plastic materials with special properties such as ethylene glycol formate film (PEN). The specific material of the plastic base is not limited here. Using plastic as a substrate can ensure the flexibility of the resulting lithium-ion battery, while also reducing the raw material cost of the battery.

In this embodiment, the lithium-ion battery can further include an encapsulation layer 106 , and the encapsulation layer 106 can at least seal the negative electrode active layer 103 , the solid electrolyte 104 and the positive electrode active layer 105 . The encapsulation layer 106 may be a flexible encapsulation film. For example, the material of the encapsulation layer 106 can be polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS) or common silica gel, and the specific material of the encapsulation layer 106 is not limited here.

It should be noted that the lithium-ion battery of this embodiment may also include structures such as positive and negative lead wires, a central terminal, and a safety valve, all of which may be arranged in a conventional manner and will not be repeated here.

In the lithium-ion battery provided in this embodiment, the positive and negative conductive current-collecting layers are formed on the same layer on the substrate, which can simplify the manufacturing process and assembly process of the battery.

The electrolyte layer 104 of the lithium ion battery provided in this embodiment is a solid electrolyte, and the lithium ion battery can overcome the potential danger of battery explosion caused by liquid lithium ion battery leakage or short circuit.

The base material of the lithium-ion battery provided in this embodiment can be an ordinary plastic material, or a special plastic material can be selected according to the service conditions of the device, so as to make the lithium-ion battery flexible and reduce the raw material cost of the lithium-ion battery.

The lithium-ion battery of this embodiment is flexible and can be used in flexible electronic devices. FIG. 3 is a picture of a lithium-ion battery provided by an embodiment of the present invention subjected to a bending test. It can be seen that the lithium-ion battery provided by this embodiment can be bent at will and has good flexibility.

In addition, in this embodiment, since the lithium-ion battery can use transparent conductive films such as ITO and IGZO as the conductive current-collecting layer, it can be used as an energy storage device and an energy supply device for flexible electronic devices compatible with lithium-ion batteries and solar cells.

Embodiment four

4A and 4B are respectively a plan view and a cross-sectional view of a lithium-ion battery provided in this embodiment, and the lithium-ion battery includes: a first conductive current collecting layer 2021 and a second conductive current collecting layer 2022 formed on a substrate 201 , the first conductive current collecting layer 2021 and the second conductive current collecting layer 2022 are insulated from each other.

Different from Embodiment 3, in this embodiment, the first conductive current collecting layer 2021 is in the shape of "concave", the second conductive current collecting layer 2022 is in the shape of "convex", and the concave shape of the first conductive current collecting layer 2021 is Partially covering the protruding part of the second conductive current collecting layer 2022; the first electrode material layer is disposed on the protruding part of the first conductive current collecting layer 1021; the second electrode material layer is disposed on the second conductive current collecting layer 1022; the electrolyte Layer 204 is disposed between the first electrode material layer and the second electrode material layer.

In this embodiment, the first electrode material layer can be the negative electrode active layer 203, the second electrode material layer can be the positive electrode active layer 205, the electrolyte layer 204 is arranged on the first electrode material layer, that is, the negative electrode active layer 203, and the second electrode material layer can be the positive electrode active layer 205. The material, that is, the positive electrode active layer 205 is provided on the electrolyte layer 204 .

It should be noted that in this embodiment, the first electrode material layer can also be a positive electrode active layer, while the second electrode material layer is a negative electrode active layer, and the specific polarities of the first electrode material layer and the second electrode material layer are set here No limit.

Likewise, the lithium ion battery provided in this embodiment may further include an encapsulation layer 206 , and the encapsulation layer 206 at least seals the negative electrode active layer 203 , the solid electrolyte 204 and the positive electrode active layer 205 .

In this embodiment, the material of each functional layer is the same as that of the above embodiment, so details are not repeated here.

The following points need to be explained:

(1) Embodiments of the present invention The drawings only relate to the structures related to the embodiments of the present invention, other structures can refer to the general design.

(2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of layers or regions is enlarged or reduced, that is, these drawings are not drawn according to actual scale. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element, Or intervening elements may be present.

(3) In the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto, and the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. A solid electrolyte, comprising: matrix, lithium salt and polyethylene oxide additive. 2. The solid electrolyte according to claim 1, wherein the matrix is ethoxytrimethylolpropane triacrylate. 3. The solid electrolyte according to claim 1, wherein the lithium salt is lithium bistrifluoromethanesulfonimide. 4. The solid electrolyte according to claim 1, further comprising inorganic nanoparticles. 5. The solid electrolyte according to claim 1, further comprising an ultraviolet polymerization initiator. 6. A battery, comprising a positive electrode active material, a negative electrode active material, and a solid electrolyte according to claims 1-5 between the positive electrode active material and the negative electrode active material. 7. A method for preparing a solid electrolyte, comprising: mixing a matrix, a lithium salt solution, and an additive polyethylene oxide to form a solid electrolyte precursor solution, and forming the solid electrolyte after curing. 8. The method for preparing a solid electrolyte according to claim 7, wherein the lithium salt solution is a lithium bistrifluoromethanesulfonimide solution. 9. The preparation method of the solid electrolyte according to claim 8, wherein the lithium bistrifluoromethanesulfonimide is dissolved in an anhydrous organic solvent to form a 0.6-1.2mol/L lithium salt solution, Then mix with the matrix and the additive polyethylene oxide to form a mixed slurry. 10. The method for preparing a solid electrolyte according to claim 7, further comprising adding an ultraviolet polymerization initiator into the mixed slurry, and irradiating with ultraviolet light to cure the mixed slurry.