KR102600942B1 - Batteries based on organosulfur species - Google Patents

Abstract

One or more organosulfur species, such as organic polysulfides and organic polythiolates, as part of a liquid or gel electrolyte, as part of the cathode, as part of the anode (or to treat the anode), and/or in the absence of an intermediate separator. Metal-sulfur batteries, such as lithium-sulfur batteries, are prepared by using them as part of the functionalized porous polymers provided.

Description

Batteries based on organosulfur species

The present invention relates to anodes based on sodium, lithium, potassium, magnesium or mixtures thereof or alloys or complexes of sodium, lithium, potassium and/or magnesium with one or more other metals, and elemental sulfur, selenium or chalcogen. relates to a battery with a cathode based on a mixture of elements, the anode and the cathode being without a separator having a liquid or gel electrolyte of a conductive salt in a non-aqueous polar aprotic solvent or polymer in contact with the electrodes They are separated by (separator element).

Electrochemical batteries are the main means for storing and transmitting electrical energy. As energy demand increases in electronics, transportation and grid-storage, batteries with greater power storage and delivery capabilities will continue to be required in the future.

Lithium-ion batteries have been widely used in portable electronics since the early 1990s because they are lightweight and have a high energy storage capacity compared to other types of batteries. However, current Li-ion battery technology does not meet the high-power and high-energy requirements of large-scale applications such as grid storage or electric vehicles with driving ranges that can compete with vehicles powered by internal combustion engines. Therefore, extensive efforts are continuing in the science and technology industry to obtain batteries with greater energy density and capacity.

Sodium-sulfur electrochemical cells and lithium-sulfur electrochemical cells are attracting attention as “next-generation” battery systems because they offer even higher theoretical energy capacities than Li-ion cells. Electrochemical conversion of elemental sulfur to monomeric sulfide (S ^2- ) provides a theoretical capacity of 1675 mAh/g compared to a Li-ion cell of less than 300 mAh/g.

Sodium-sulfur batteries have been developed and released as commercial systems. Unfortunately, sodium-sulfur cells typically require high temperatures (above 300°C) to function, making them suitable only for large stationary applications.

Only lithium-sulfur electrochemical cells, first proposed in the late 1950s and 1960s, are currently being developed as commercial battery systems. These cells provide a theoretical specific energy density of more than 2500 Wh/kg (2800 Wh/L) compared to 624 Wh/g for lithium-ion cells. Compared to 100 Wh/g for Li-ion cells, the demonstrated specific energy density for Li-S cells ranges from 250 to 350 Wh/kg, this lower limit being a result of the specific characteristics of the electrochemical processes for the system during charging and discharging. am. Considering that the actual specific energy of a lithium battery is typically 25 to 35% of the theoretical value, the optimal practical specific energy for a Li-S system would be approximately 780 Wh/g (30% of the theoretical value) [V.S. Kolosnitsyn, E. Karaseva, US Patent Application 2008/0100624 A1].

Lithium-sulfur chemistry has a number of technical challenges that hinder the development of such electrochemical cells, particularly poor discharge-charge cyclability. Nevertheless, due to the inherent light weight, low cost, and high power capacity of lithium-sulfur cells, there is great interest in improving the performance of lithium-sulfur systems, and over the past two decades, many researchers around the world have worked extensively to address these issues [ C. Liang, et al . in Handbook of Battery Materials 2nd ^Ed . , Chapter 14, pp. 811-840 (2011); VS Kolosnitsyn, et al ., J. Power Sources 2011 , 196 , 1478-82; and references herein].

The design of a cell for a lithium-sulfur system typically includes:

ㆍ Anode made of lithium metal, lithium-alloy or lithium-containing composite.

· Non-reactive porous separator (often polypropylene or α-alumina) between anode and cathode. The presence of this separation membrane separates the anolyte compartment and the catholyte compartment.

ㆍ Porous sulfur-containing, incorporating binder (often polyvinylidene difluoride) and conductivity-enhancing material (often graphite, mesoporous graphite, multi-walled carbon nanotubes, graphene) cathode.

ㆍ Polar aprotic solvent and one or more conductive Li salts [(CF ₃ SO ₂ ) ₂ N ^- , CF ₃ SO ₃ ^- , CH ₃ SO ₃ ^- , ClO ₄ ^- , PF ₆ ^- , AsF ₆ ^- , halogen, etc.] An electrolyte consisting of Solvents used in these cells include basic (cation-complexing) aprotic polar solvents such as sulfolane, dimethyl sulfoxide, dimethylacetamide, tetramethyl urea, N -methyl pyrrolidinone, tetramethyl Includes ethyl sulfamide, tetrahydrofuran, methyl-THF, 1,3-dioxolane, diglyme and tetraglyme. Solvents with low polarity are not suitable because they have poor conductivity and poor ability to dissolve Li ⁺ species, and protic solvents can react with Li metal. In the solid state version of the lithium-sulfur cell, the liquid solvent is replaced by a polymeric material such as polyethylene oxide.

ㆍ Current collector and appropriate casing material.

The present invention provides compositions and uses of organic polysulfides, organic thiolate and organic polythiolate for use in metal-sulfur batteries, especially lithium-sulfur batteries. Organic polysulfide, organic thiolate, and organopolythiolate species (hereinafter often referred to as “organosulfur species”) play a role in improving the performance of electrochemical cells during repeated discharge and charge cycles. do.

The present invention therefore relates to a chemical energy source comprising a cell or battery with at least one positive electrode (cathode), at least one negative electrode (anode) and an electrolyte medium, its operative chemistry ) includes reduction of sulfur or polysulfide species and oxidation of reactive metal species. The cathode comprises a reactive metal such as lithium, sodium, potassium, magnesium or an alloy/complex of these metals with another metal, and in certain embodiments the cathode comprises one or more organosulfur species and/or one or more organosulfur species. It is processed as . The anode comprises elemental sulfur and/or elemental selenium, and, in certain embodiments of the invention, organosulfur species, such as organic polysulfide species and/or metal organic polysulfide salts, and a matrix containing these species. . In certain embodiments, the electrolyte matrix includes a mixture of organic solvents or polymers, inorganic or organic polysulfide species, carriers for ionic forms of reactive metals, and other components to optimize electrochemical performance.

Specifically, the present invention relates to organic sulfides and polysulfides as components of cathodes and electrolyte matrices, and their lithium (or sodium, potassium, magnesium, quaternary ammonium or quaternary phosphonium) organothiolate or organopolythiolate. It concerns the use of analogues. The organosulfur species are chemically combined with sulfur and anionic mono- or polysulfide species to form organopolythiolate chemistry with increased affinity for the non-polar sulfur components of the positive cathode and catholyte phases. form a species Additionally, the organosulfur species can react with the reactive metal or metals present in the cathode to form metal salts of the organosulfur species on the cathode surface, which can be used to produce electrolytes containing such organosulfur species-treated cathodes. Helps improve the performance of chemical cells. Without wishing to be bound by theory, the organosulfur species is chemically combined with the reactive metal(s) of the anode and is a combination of the dissolved Li ₂ S _n (n≥1) species often present in the electrolytes used in metal sulfur batteries. It is believed that as a result of the reaction in , buildup of LiS ₂ on the anode is prevented. Accordingly, the presence of organosulfur species or treatment of the anode with organosulfur species results in a co-current flow of sulfur atoms or anions from the cathode to the anode by forming a protective layer on the anode surface capable of conducting metal cations ( It can help prevent translational flow. The electrolyte is saturated in metal polysulfide species, resulting in less sulfur loss from the cathode, higher battery capacity, and increased overall cycling life of the battery.

One aspect of the present invention is a battery,

a) an anode containing an anode active material comprising sodium, lithium, potassium, magnesium, or an alloy or complex of one or more of sodium, lithium, potassium or magnesium with one or more other metals to provide ions;

b) a cathode comprising a cathode active material comprising a mixture of elemental sulfur, elemental selenium, or chalcogen elements; and

c) an intermediate separator element located between the anode and the cathode, which functions to separate the liquid or gel electrolyte in contact with the anode and the cathode, through which the anode and the cathode are separated during the charging and discharging cycle of the battery. No intermediate separator between which metal ions and their counter ions move.

Including,

The liquid or gel electrolyte solution includes a non-aqueous polar aprotic solvent or polymer and a conducting salt,

(i) at least one of the liquid or gel electrolyte solution further comprises one or more organosulfur species,

(ii) the cathode is further comprised of one or more organosulfur species;

(iii) the intermediate separator member comprises a functionalized porous polymer containing one or more organosulfur species;

(iv) the anode further consists of one or more organosulfur species or is treated with one or more organosulfur species;

One or more of the following is met,

Organosulfur species include one or more organic moieties and one or more -SS _n - linkages, where n is 0 or an integer of 1 or more.

Batteries are provided.

In one aspect, only one of conditions (i), (ii), (iii) or (iv) is met. In another embodiment, all four conditions are met. In another embodiment, only two or three of the conditions, for example (i) and (ii), (i) and (iii), (ii) and (iii), (i), (ii) and (iii), (ii), (iii) and (iv), (i), (iii) and (iv), or (i), (ii) and (iv) are satisfied.

In another aspect, the invention provides a polymer comprising: one or more non-aqueous polar aprotic solvents or polymers; one or more conducting salts; and at least one organosulfur species consisting of at least one organic moiety and at least one -SS _n - linkage, where n is 0 or an integer of 1 or more.

Another aspect of the present invention is a) a mixture of elemental sulfur, elemental selenium, or chalcogen elements, b) one or more electrically conductive additives, and c) one or more organic moieties with one or more -SS _n - linkages, where n is 0 or an integer greater than or equal to 1).

A further aspect of the invention includes an anode active material comprising sodium, lithium, potassium, magnesium, or an alloy or complex of one or more of sodium, lithium, potassium, or magnesium with one or more other metals to provide ions. Provided is an anode, wherein the anode further comprises one or more organosulfur species comprising one or more organic moieties and one or more -SS _n - linkages, where n is 0 or an integer of 1 or more, or It is treated with the above organic sulfur chemical species. This treatment increases battery life and reduces capacity fade in subsequent cycles.

Organosulfur species are, for example, organic polysulfides, organic thiolates, where n = 0 and correspond, for example, to the general formula RSM, where R is an organic moiety and M is Li, Na, K , Mg, quaternary ammonium, or quaternary phosphonium) and/or metal organic polythiolate. In certain embodiments of the invention, the organosulfur species is dithioacetal, dithioketal, trithio-orthocarbonate, thiosulfonate [-S(O) ₂ -S-], thiosulfinate [-S(O) -S-], thiocarboxylate [-C(O)-S-], dithiocarboxylate [-C(S)-S-], thiophosphate, thiophosphonate, monothiocarbonate, dithiocarbonate, and at least one sulfur-containing functional group selected from the group consisting of trithiocarbonate. In other embodiments, the organosulfur species may be selected from the group consisting of aromatic polysulfides, polyether-polysulfides, polysulfide-acid salts, and mixtures thereof.

Figure 1 shows the discharge profile of a lithium-sulfur battery containing nC ₁₂ H ₂₅ SLi added to the cathode during 3 to 63 repeated charge/discharge cycles.
_{Figure 2 shows the presence and} A comparison of the cycling performance of cells prepared in the absence and absence is shown.

Electrically active materials structured for use in batteries are referred to as electrodes. Among a pair of electrodes used in a battery that serves as a chemical source of electrical energy, the electrode with the higher electrochemical potential is called the anode or cathode, and the electrode with the lower electrochemical potential is called the cathode or anode. It is referred to as. As used herein, using the common nomenclature for batteries, “cathode” or “anode” and “anode” or “cathode” refer to the electrochemical function of the electrodes during cell discharge to provide electrical energy. . During the charging portion of the cycle, the actual electrochemical function of the electrodes is opposite to what occurred during discharge, but the specifications for each electrode remain the same as during discharge.

Electrochemical cells are usually combined in series, and a collection of these cells is referred to as a battery. Based on the operating chemistry of the cells, primary batteries are designed for a single discharge to provide power for external devices. Secondary batteries can be recharged using electrical energy from an external source and are therefore widely used over multiple discharge and charge cycles.

The electrochemical active material used in the cathode or positive electrode is hereinafter referred to as the cathode active material. The electrochemical active material used in the anode or cathode is hereinafter referred to as anode active material. A multi-component composition that is electrochemically active and contains an electrochemically active material and optional electrically conductive additives and binders as well as other optional additives is hereinafter referred to as an electrode composition. A battery including a cathode containing a cathode active material in an oxidized state and an anode containing an anode active material in a reduced state is referred to as being in a charged state. Accordingly, a battery including a cathode containing a cathode active material in a reduced state and an anode containing an anode active material in an oxidized state is referred to as being in a discharged state.

Without wishing to be bound by theory, certain possible advantages or features of the present invention are as follows. Organosulfur species can partition into a sulfur-rich catholyte phase. Dianionic sulfides or polysulfides (e.g. Li ₂ S _x , x = 1, 2, 3…) and organopolysulfides, organothiolates or organopolythiolates (e.g. _RS The chemical exchange reaction between R' or RS _x -Li, R and R' = organic moieties, It is advantageous for minimizing the amount of dianionic polysulfide in the liquid and for redepositing sulfur and sulfur-containing species at the cathode. Net removal of dianionic polysulfide lowers electrolyte viscosity, thereby minimizing the deleterious effects of high viscosity on electrolyte conductivity. Organosulfur species also increase the dissolution of insoluble low-rank lithium sulfide species (particularly Li ₂ S and Li ₂ S ₂ ) in the catholyte and anode phases, making them scavengers. It can scavenge, minimizing the loss of reactive lithium species during repeated charge/discharge cycles. The performance of organosulfur species can be “tuned” depending on the choice of organic functionality. For example, shorter chain alkyl or alkyl groups with stronger polar functionality can be partitioned further into the anolyte phase, and longer chain or less polar analogues can be partitioned further into the catholyte phase. By controlling the relative ratios of long chain/non-polar and short chain/polar chain organic species, it will provide a means of controlling the partitioning of sulfur-containing species relative to the cathode/cathode fluid. Moreover, since polysulfides or polythiolates present in certain amounts in the anolyte are advantageous as a means of controlling lithium dendrite growth on the anode during charging, the organic moieties and their relative ratios Appropriate selection of will provide greater control over dendrite growth.

Organosulfur species useful in the present invention include one or more organic moieties and one or more -SS _n - linkages, where n is 0 or an integer greater than or equal to 1. In one embodiment, the organosulfur species consists of organic moieties (which may be the same or different from each other) connected by a -SS _n - (polysulfide) linkage, where n is an integer greater than or equal to 1. Contains 2 per molecule. The -SS _n - linkage may form part of a larger linker, such as the -Y ¹ -C(Y ² Y ³ )-SS _n - linkage or the -Y ¹ -C(=Y ⁴ )-SS _n - linkage. , where Y ¹ is O or S, and Y ² and Y ³ are independently an organic moiety or -SS _o -Z (where o is 1 or more and Z is an organic moiety or Li, Na, K, It is a chemical species selected from Mg, quaternary ammonium, or quaternary phosphonium), and Y ⁴ is O or S. In another embodiment, the organosulfur species contains a monovalent organic moiety and a species selected from Na, Li, K, Mg, quaternary ammonium and quaternary phosphonium, which have a -SS _n - linkage (e.g. For example, -Y ¹ -C(Y ² Y ³ )-SS _n -connection or -Y ¹ -C(=Y ⁴ )-SS _n -connection, where n = 0 or an integer greater than or equal to 1) are connected by In another embodiment, the -SS _n - linkage can be on any side of the organic moiety. For example, the organic moiety is an optionally substituted divalent aromatic moiety, C(R ³ ) ₂ wherein each R ³ is independently H or an organic moiety such as a C ₁ -C ₂₀ organic moiety. ), carbonyl (C=O), or thiocarbonyl (C=S).

Organosulfur species include, for example, dithioacetal, dithioketal, trithio-orthocarbonate, aromatic polysulfide, polyether-polysulfide, polysulfide-acid salt, thiosulfonate [-S(O) ₂ -S-], thiosulfinate [-S(O)-S-], thiocarboxylate [-C(O)-S-], dithiocarboxylate [-RC(S)-S-], thiophosphate or organic polysulfides, organic thiolate, organic polythiolate, including those having sulfur-containing functional groups such as thiophosphonate functional groups, or mono-, di- or trithiocarbonate functional groups; Organometallic polysulfides containing these or similar functional groups; and mixtures thereof.

Suitable organic moieties include, for example, monovalent, divalent and multivalent organic moieties, which may contain branched, linear and/or cyclic hydrocarbyl groups. As used herein, the term "organic moiety" refers to a moiety that, in addition to carbon and hydrogen, may contain one or more heteroatoms such as oxygen, nitrogen, sulfur, halogen, phosphorus, selenium, silicon, metal (e.g. tin), etc. Includes. Heteroatom(s) may be present in the organic moiety in the form of a functional group. Accordingly, hydrocarbyl and functionalized hydrocarbyl groups are considered organic moieties within the scope of the present invention. In one embodiment, the organic moiety is a C ₁ -C ₂₀ organic moiety. In another aspect, the organic moiety contains two or more carbon atoms. Accordingly, the organic moiety may be a C ₂ -C ₂₀ organic moiety.

Organosulfur species may be monomeric, oligomeric, or polymeric in nature. For example, the -SS _n - functional group may be pendant to the backbone of an oligomeric or polymeric species containing two or more monomer repeat units in its backbone. The -SS _n - functional group can be incorporated into the backbone of such oligomer or polymer, such that the oligomer or polymer backbone contains a plurality of -SS _n - linkages.

Organosulfur species are, for example, organic compounds of the formula R ¹ -SS _n -R ² where R ¹ and R ² independently represent a C ₁ -C ₂₀ organic moiety and n is an integer of 1 or greater. It may be a polysulfide or a mixture of organic polysulfides. The C ₁ -C ₂₀ organic moiety may be a branched, linear or cyclic monovalent hydrocarbyl group. R ¹ and R ² are each independently a C ₉ -C ₁₄ hydrocarbyl group with n = 1 (giving a disulfide, for example tertiary-dodecyl disulfide). In another embodiment, R ¹ and R ² are each independently a C ₉ -C ₁₄ hydrocarbyl group with n = 2 to 5 (to provide a polysulfide). Examples of such compounds include TPS-32 and TPS-20, available commercially from Arkema. In another embodiment, R ¹ and R ² are independently a hydrocarbyl group under C ₇ -C ₁₁ where n = 2 to 5. One example of a suitable polysulfide of this type is TPS-37LS, commercially available from Arkema. Another type of suitable polysulfide would be a polysulfide or mixture of polysulfides where R ¹ and R ² are both tert-butyl and n = 2 to 5. Examples of such organosulfur compounds include TPS-44 and TPS-54 commercially available from Arkema.

Organosulfur species also have the formula R ¹ -SS _n -M, where R ¹ is a C ₁ -C ₂₀ organic moiety and M is lithium, sodium, potassium, magnesium, quaternary ammonium, or quaternary phosphonium. , n is an integer of 1 or more) or an organic polythiolate of the formula R ² -SM (where R ² is a C ₁ -C ₂₀ organic moiety, and M is lithium, sodium, potassium, magnesium, quaternary ammonium, or It may be an organic thiolate of quaternary phosphonium.

In another embodiment, the organosulfur species may be a dithioacetal or dithioketal such as those corresponding to formulas (I) and (II) or a trithio-orthocarboxylate of formula (III):

where each R ³ is independently H or a C ₁ -C ₂₀ organic moiety, o, p and q are each independently an integer of 1 or more, and each Z is independently a C ₁ -C ₂₀ organic moiety, Li, Na, K, Mg, quaternary ammonium, or quaternary phosphonium. Examples of these organosulfur species are 1,2,4,5-tetrathiane (formula I, R ³ = H, o = p = 1), tetramethyl-1,2,4,5-tetrathiane (Formula I, R ³ = CH ₃ , o = p =1), and oligomeric or polymeric species thereof.

Another aspect of the invention is an organic polysulfide of formula (IV), a polyether-polysulfide of formula (V), a polysulfide-acid salt of formula (VI), or a polysulfide-acid salt of formula (VII). Sulfur species are used:

wherein in formula (IV) having an aromatic ring optionally substituted with a substituent other than hydrogen at one or more other positions, R ⁴ is independently tert-butyl or tert-amyl, R ⁵ is independently OH, OLi or ONa, r is 0 or more (eg, 0 to 10); R ⁶ in formula (VI) is a divalent organic moiety; In formula (VII) R ⁷ is a divalent organic moiety, each Z is independently a C ₁ -C ₂₀ organic moiety, Li, Na, K, Mg, quaternary ammonium or quaternary phosphonium, and each M is independently Li, Na, K, Mg, quaternary ammonium, or quaternary phosphonium, and o and p are each independently an integer of 1 or more. Examples of such organosulfur species include aromatic polysulfides (formula IV, where R ⁴ = tert-butyl or tert-amyl and R ⁵ = OH) available commercially from Arkema under the trade name Vultac ^® ; and derived from mercapto-acids such as mercaptoacetic acid, mercaptopropionic acid, mercaptoethanesulfonic acid, mercaptopropanesulfonic acid or from olefin-containing acids such as vinylsulfonic acid or 2-acrylamido-2-methylpropanesulfonic acid. , polysulfide-acid salts corresponding to formulas (VI) and (VII).

In another embodiment, the organosulfur species is an organic- or organo-metal polysulfide containing a trithiocarbonate functionality of Formula (IX), an organic- or organo-metal polysulfide containing a dithiocarbonate functionality of Formula (X) sulfide, or an organic- or organo-metallic polysulfide containing a monothiocarbonate of formula (XI):

Here, Z is a C ₁ -C ₂₀ organic moiety, Na, Li, K, Mg, quaternary ammonium, or quaternary phosphonium, and o and p are independently integers of 1 or more.

The liquid or gel electrolyte is a dimetal poly of the formula MSS _n -M (where M is independently Li, Na, K, Mg, quaternary ammonium, or quaternary phosphonium, and n is an integer of 1 or more) It may further consist of thiolate chemical species. Accordingly, this species, unlike the organosulfur species described above, does not contain any organic moieties.

The intermediate separator member may function as a divider between compartments within the electrochemical cell. One compartment may contain an electrolyte in contact with the cathode (the electrolyte within this compartment may be referred to as the catholyte). Another compartment may contain an electrolyte in contact with the anode (the electrolyte within this compartment may be referred to as the anolyte). The anode fluid and cathode fluid may be the same or different from each other. One or both of the anolyte and catholyte may contain one or more organosulfur species according to the present invention. The intermediate separator member is positioned between these compartments in such a way that ions from the anolyte can pass through the intermediate separator member and enter the catholyte or vice versa, depending on whether the electrochemical cell is operated in charge or discharge mode. can do.

In a further aspect of the invention, the intermediate separator member is comprised of a porous polymer. The porous polymer may be composed of, for example, polypropylene, polyethylene, or fluorinated polymers. Porous polymers can be functionalized with organosulfur species of the types described above. The organosulfur species may be pendant to the backbone of the porous polymer, may be present in crosslinks between the backbones of individual polymer chains, and/or may be incorporated into the backbone of the porous polymer. Accordingly, the backbone of the porous polymer may contain one or more -SS _n - linkages and/or the -SS _n - linkages may be pendant to the polymer backbone. These -SS _n - linkages can also be present in crosslinks.

Solvents suitable for use in the electrochemical cells according to the invention are any of the basic (cation-complex) aprotic polar solvents generally known or used for lithium-sulfur batteries, for example Sulfolane, dimethyl sulfoxide, dimethylacetamide, tetramethyl urea, N-methyl pyrrolidinone, tetraethyl sulfamide; ethers such as tetrahydrofuran, methyl-THF, 1,3-dioxolane, 1,2-dimethoxyethane (glyme), diglyme, and tetraglyme, and mixtures thereof; Carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, methylpropylcarbonate, ethylpropylcarbonate, etc.; and esters such as methyl acetate, ethyl acetate, propyl acetate, and gamma-butyrolactone. The electrolyte may contain these solvents alone or a mixture of these solvents. Any of the polar aprotic polymers known in the battery field may be used. The electrolyte may comprise a polymeric material and may take the form of a gel. Polymers suitable for use in electrolytes may include, for example, polyethylene oxide, polyethersulfone, polyvinyl alcohol, or polyimide. The electrolyte may be in the form of a gel, which may be a three-dimensional network composed of liquid and binder components. The liquid may be a monomer solvent entrained in a polymer, such as a cross-linked polymer.

One or more conducting salts are present in the electrolyte in combination with a non-aqueous polar aprotic solvent and/or polymer. Conducting salts are well known in the battery field, for example (CF ₃ SO ₂ ) ₂ N ^- , CF ₃ SO ₃ ^- , CH ₃ SO ₃ ^- , ClO ₄ ^- , PF ₆ ^- , AsF ₆ ^- , nitrate. , halogen and other lithium salts. Sodium and other alkali metal salts and mixtures thereof may also be used.

The anode active material may include an alkali metal such as lithium, sodium, potassium and/or magnesium or other active material or composition. Particularly preferred anode active materials include metallic lithium, alloys of lithium, metallic sodium, alloys of sodium, alkali metals or alloys thereof, metal powders, alloys of lithium and aluminum, magnesium, silicon, and/or tin, alkali metal-carbon and alkali. It includes metal-graphite intercalates, compounds capable of reversible oxidation and reduction by alkali metal ions, and mixtures thereof. The metal or metal alloy (eg, metallic lithium) may be contained inside the battery as one film, or as several films, optionally separated by a ceramic material. Suitable ceramic materials include, for example, silica, alumina, or lithium-containing glassy materials, such as lithium phosphate, lithium aluminate, lithium silicate, lithium phosphorus oxynitride, lithium tantalum oxide, lithium aluminosilicate, lithium titanium. oxides, lithium silicosulfide, lithium germanosulfide, lithium aluminosulfide, lithium borosulfide, lithium phosphosulfide and mixtures thereof.

The anode may be in any suitable form, such as, for example, a foil, composite, or other type of current collector.

In one aspect of the invention, the anode is treated with one or more organosulfur species. This treatment can be accomplished by contacting the surface of the anode with one or more organosulfur species. The organosulfur species may, for example, be in solution form during this contacting step. Any solvent or combination of solvents suitable for the organosulfur species can be used to form this solvent. For example, the solvent(s) can be any of the aprotic polar solvents described above. In one embodiment, the anode is treated with organosulfur species prior to assembling the electrochemical cell, for example, by spraying a solution of the organosulfur species onto the anode or by immersing the anode in a solution of the organosulfur species. . In another embodiment, the organosulfur species is incorporated as a component of the electrolyte to be used within the electrochemical cell, wherein the electrolyte containing organosulfur species is brought into contact with the anode on the assembly of the electrochemical cell.

In another embodiment, the anode includes one or more organosulfur species in addition to one or more reactive metals selected from the group consisting of lithium, sodium, potassium, and magnesium. For example, one or more organosulfur species can be deposited on the surface of the anode.

The cathode includes elemental sulfur, elemental selenium, or a mixture of chalcogen elements. In one aspect, the cathode is further comprised of one or more organosulfur species as described in detail above. The cathode may additionally and/or alternatively be comprised of binders and/or electrically conductive additives. Suitable binders include, for example, polyvinyl alcohol, polyacrylonitrile, polyvinylidene fluoride (PVDF), polyvinyl fluoride, polytetrafluoroethylene (PTFE), tetrafluoroethylene and hexafluoropropylene. Polymers such as copolymers, copolymers of vinylidene fluoride and hexafluoropropylene, copolymers of vinylidene fluoride and tetrafluoroethylene, ethylene-propylene-diene monomer rubber (EPDM), and polyvinyl chloride (PVC) Includes. The electrically conductive additive may be, for example, carbon in an electrically conductive form such as graphite, graphene, carbon fibers, carbon nanofibers, carbon black or soot (e.g. lamp or furnace soot). You can. The cathode may be present in the battery or electrochemical cell in combination with a current collector, such as any of the current collectors known in the battery or electrochemical cell art. For example, the cathode can be coated on the surface of a metallic current collector.

Aspects of the invention include:

1. As a battery,

a) an anode containing an anode active material comprising sodium, lithium, or an alloy or complex of one or more of sodium or lithium with one or more other metals to provide ions;

b) a cathode comprising a cathode active material comprising a mixture of elemental sulfur, elemental selenium, or chalcogen elements; and

c) an intermediate separator member located between the anode and the cathode, which functions to separate the liquid or gel electrolyte in contact with the anode and the cathode, through which metal ions and Absence of an intermediate separator through which its counterions move

Including,

The liquid or gel electrolyte solution includes a non-aqueous polar aprotic solvent or polymer and a conducting salt,

(i) at least one of the liquid or gel electrolyte solution further comprises one or more organosulfur species,

(ii) the cathode is further comprised of one or more organosulfur species;

(iii) the intermediate separator member comprises a functionalized porous polymer containing one or more organosulfur species;

(iv) the anode further consists of one or more organosulfur species or is treated with one or more organosulfur species;

One or more of the following is met,

The battery, wherein the organosulfur species comprises one or more organic moieties and one or more -SS _n - linkages, where n is 0 or an integer greater than or equal to 1.

2. The battery according to clause 1, wherein the organosulfur species is selected from the group consisting of organic polysulfides, organic thiolate and organic polythiolate and mixtures thereof.

3. The method of any one of items 1 and 2, wherein the organosulfur species is dithioacetal, dithioketal, trithio-orthocarbonate, thiosulfonate [-S(O) ₂ -S-], thio Sulfinate [-S(O)-S-], thiocarboxylate [-C(O)-S-], dithiocarboxylate [-C(S)-S-], thiophosphate, thiophosphonate, A battery containing at least one sulfur-containing functional group selected from the group consisting of monothiocarbonate, dithiocarbonate, and trithiocarbonate.

4. The battery according to any one of clauses 1 to 3, wherein the organosulfur species is selected from the group consisting of aromatic polysulfides, polyether-polysulfides, polysulfide-acid salts and mixtures thereof.

5. The method of any one of items 1 to 5, wherein the organosulfur species has the formula R ¹ -SS _n -R ² wherein R ¹ and R ² are independently linear, branched, or cyclic aliphatic or aromatic. represents a C ₁ -C ₂₀ organic moiety, which may optionally include one or more functional groups containing N, O, P, S, Se, Si, Sn, halogen and/or metal, and n is 1 or more is an integer), which is an organic polysulfide, battery.

6. The method according to any one of claims 1 to 5, wherein the organosulfur species is an organic thiolate of the formula R ¹ -SM or an organic polythiolate of the formula R ¹ -SS _n -M, where R ¹ is a linear , branched, or cyclic C ₁ -C ₂₀ organic, which may be aliphatic or aromatic and may optionally contain one or more functional groups containing N, O, P, S, Se, Si, Sn, halogens and/or metals. moiety, M is lithium, sodium, potassium, magnesium, quaternary ammonium, or quaternary phosphonium, and n is an integer greater than or equal to 1.

7. The organosulfur species according to any one of claims 1 to 6, wherein the organosulfur species is a dithioacetal or dithioketal of formula (I) or (II) or a trithio-orthocarboxylate of formula (III). battery.

where each R ³ may independently be H, or may be linear, branched, or cyclic aliphatic or aromatic and may contain one or more functionalities containing N, O, P, S, Se, Si, Sn, halogen and/or metal. is a C ₁ -C ₂₀ organic moiety which may optionally contain the group, o, p and q are each independently an integer of 1 or more, and each Z is independently linear, branched, or cyclic aliphatic or aromatic. C ₁ -C ₂₀ organic moieties, which may optionally include one or more functional groups containing N, O, P, S, Se, Si, Sn, halogens and/or metals; Li; Na; K; Mg; quaternary ammonium; or quaternary phosphonium.

8. The organosulfur species according to any one of claims 1 to 7, wherein the organosulfur species is an aromatic polysulfide of formula (IV), a polyether-polysulfide of formula (V), a polysulfide-acid salt of formula (VI) , or a polysulfide-acid salt of formula (VII).

wherein in formula (IV) having an aromatic ring optionally substituted at one or more positions with a substituent other than hydrogen, R ⁴ is independently tert-butyl or tert-amyl, R ⁵ is independently OH, OLi or ONa, r is at least 0, in formula (VI) R ⁶ is a divalent organic moiety, in formula (VII) R ⁷ is a divalent organic moiety, and each Z is independently a C ₁ -C ₂₀ organic moiety , Li, Na or quaternary ammonium, each M is independently Li, Na, K, Mg, quaternary ammonium, or quaternary phosphonium, and o and p are each independently an integer of 1 or more.

9. The organosulfur species according to any one of claims 1 to 8, wherein the organosulfur species is an organic- or organo-metal polysulfide containing a trithiocarbonate functional group of formula (IX), a dithiocarbonate functional group of formula (X) A battery comprising:

Here, Z is a C ₁ -C ₂₀ organic moiety, Na, Li, quaternary ammonium or quaternary phosphonium, and o and p are each independently an integer of 1 or more.

10. The method of any one of items 1 to 9, wherein the liquid or gel electrolyte has the formula MSS _n -M, where each M is independently Li, Na, K, Mg, quaternary ammonium, or quaternary phosphide. phonium, and n is an integer greater than or equal to 1).

11. The battery according to any one of claims 1 to 10, wherein the cathode further consists of one or more electrically conductive additives and/or one or more binders.

12. The battery according to any one of claims 1 to 11, wherein the organosulfur species is pendant to the main chain of the functionalized porous polymer.

13. The battery according to any one of claims 1 to 12, wherein the organosulfur species is crosslinked within or forms part of the main chain of the functionalized porous polymer.

14. The battery according to any one of clauses 1 to 13, wherein the organic moiety contains at least 2 carbon atoms.

15. The method of any one of clauses 1 to 14, wherein the mesoporous separator separates the battery and provides an anolyte portion associated with the anode and a catholyte portion associated with the cathode, and the organosulfur species is present in the anolyte portion or the cathode portion. Battery, present in one or more of the catholyte portions.

16. The method according to any one of items 1 to 15, wherein the non-aqueous polar aprotic solvent or polymer is ether, carbonyl, ester, carbonate, amino, amido, sulfidyl [-S-], sulfinyl [ -S(O)-], or sulfonyl [-SO ₂ -].

17. The method according to any one of items 1 to 16, wherein the conducting salt has the formula MX, where M is Li, Na or quaternary ammonium and X is (CF ₃ SO ₂ ) ₂ N, CF ₃ SO ₃ , CH ₃ SO ₃ , ClO ₄ , PF ₆ , NO ₃ , AsF ₆ or halogen), corresponding to the battery.

18. The method of any one of paragraphs 1 to 17, wherein the organic moiety is an oligomer or polymer and the organosulfur species comprises one or more -S-S- linkages pendant to the main chain of the oligomeric or polymeric organic moiety. Do, battery.

19. The method of any one of paragraphs 1 to 18, wherein the organic moiety is an oligomer or polymer and the organosulfur species comprises one or more -S-S- linkages incorporated into the backbone of the oligomeric or polymeric organic moiety. battery.

20. As an electrolyte, one or more non-aqueous polar aprotic solvents or polymers; one or more conducting salts; and one or more organosulfur species consisting of one or more organic moieties and one or more -SS _n -linkages, where n is 0 or an integer of 1 or more.

21. As a cathode, a) a mixture of elemental sulfur, elemental selenium, or chalcogen elements, b) one or more electrically conductive additives, and c) one or more organic moieties and one or more -SS _n - linkages, where n is 0 or is an integer greater than or equal to 1).

22. The cathode of item 21 in combination with a current collector.

23. The cathode of any one of clauses 21 and 22, wherein the one or more electrically conductive additives comprise one or more of graphite, carbon nanotubes, carbon nanofibers, graphene, carbon black or soot.

24. The cathode according to any one of clauses 21 to 23, further comprising one or more binders.

25. An anode comprising an anode active material comprising sodium, lithium, potassium or magnesium, or an alloy or complex of one or more of sodium, lithium, potassium or magnesium with one or more other metals to provide ions, the anode comprising: It further comprises or is treated with one or more organosulfur species comprising one or more organic moieties and one or more -SS _n - linkages, where n is 0 or an integer of 1 or more. , anode.

Although the aspects have been described herein in a manner to enable a clear and concise description to be written, it is intended and will be apparent that the aspects may be combined or separated in various ways without departing from the invention. For example, it will be understood that all preferred features described herein are applicable to all aspects of the invention described herein.

In some aspects, the invention herein may be interpreted to exclude any element or process step that does not substantially affect the basic and novel characteristics of the composition or process. Additionally, in some aspects, the invention may be interpreted to exclude any element or process step not specified herein.

Example

Cathode fabrication, battery fabrication, and battery testing

Example 1

Anode containing 70% by weight sublimed elemental sulfur powder, 20% by weight polyethylene oxide (PEO, MW 4×10 ⁶ ), 10% by weight carbon black (Super P ^® Conductive, Alfa Aesar) was prepared through the following process:

A mixture of these components in N-methyl-2-pyrrolidone (NMP) was mechanically ground in a planetary milling machine. The mixture was diluted by adding acetonitrile. The resulting suspension was applied onto aluminum foil (76 μm thick) with an automatic film coater (Mathis). The coating was dried in a vacuum oven at 50°C for 18 hours. The resulting coating contained 3.10 mg/cm2 of the cathode mixture.

Example 2

A positive cathode containing lithium n-dodecyl mercaptide (10% sulfur by weight) was prepared according to the procedure described in Example 1. The resulting coating contained 3.4 mg/cm2 of sulfur.

Example 3

The positive cathode from Example 2 was used in a PTFE Swaglok cell with two stainless steel rods or a stainless steel coin cell assembly (CR2032). The battery cells were assembled in an argon-filled glove box (MBraun) as follows: the cathode electrode was placed on the lower can followed by the separator. Then, electrolyte was added to the separator. A lithium electrode was placed on the separator. A spacer and spring were placed on top of the lithium electrode. The battery core was sealed with a stainless steel rod or crimping device.

Example 4

Cathode from Example 2 (7/16" diameter), 0.5M LiTFSI solution in tetraethylene glycol dimethyl ether (TEGDME):1,3-dioxolane (DOL) = 1:1, following the procedure described in Example 3. A battery cell consisting of 20 μl, a separator, and a lithium electrode (0.38 mm thick, 7/16" diameter) was tested for charge-discharge cycling at a current of 0.1 mA. This test was performed for cutoff voltages of 1.5 V and 3.2 V at room temperature using a Gamry potentiometer (Gamry Instruments). The discharge cycle profile is shown in Figure 1.

Synthesis of lithium alkylmercaptide

Example 5 - Synthesis of lithium n-dodecyl mercaptide by hexyl lithium

n-hexyllithium (33% by weight in hexane, 1.1 eq.) was added dropwise to n-dodecyl mercaptan (9.98 g, 1 eq.) in hexane (100 mL) at -30°C, and the mixture temperature was lowered to below -20°C. maintained. The solvent was removed under reduced pressure to give a white solid in quantitative yield.

Example 6 - Synthesis of lithium n-dodecyl mercaptide by lithium hydroxide

A mixture of n-dodecyl mercaptan (2.0 g, 1 eq.) and lithium hydroxide monohydrate (0.41 g, 1 eq.) in acetonitrile (8 mL) was heated to 75°C and stirred at 75°C for 16 hours. After cooling to room temperature, the reaction mixture was filtered. The filter cake was washed with acetonitrile and dried in a vacuum oven at 50°C overnight. Lithium n-dodecyl mercaptide was obtained as a white solid in 93.5% yield (1.93 g).

Example 7 - Synthesis of lithium n-dodecyl mercaptide by hexyl lithium

Following the procedure described in Example 6, 3,6-dioxaoctane-1,8-dithiol dilithium salt was synthesized from dimercaptan in quantitative yield as a white solid.

Synthesis of lithium alkyl polythiolate

Example 8 - Synthesis of lithium n-dodecylpolythiolate by lithium hydroxide

To a nitrogen-degassed solution of n-dodecyl mercaptan (2.00 g, 1 eq.) in 1.3-dioxolane (25 mL), lithium hydroxide monohydrate (0.41 g, 1 eq.) and sulfur (1.27 g, 4 eq.) were added. did. The mixture was stirred under nitrogen for 30 minutes at room temperature. Lithium n-dodecyl polythiolate in 1,3-dioxolane was obtained as a dark red solution. Whether the mercaptan was completely converted to lithium n-dodecyl polythiolate was confirmed by ¹³ C-NMR and LCMS.

Example 9 - Synthesis of lithium 3,6-dioxaoctane-1,8-polythiolate by lithium hydroxide and sulfur

Following the procedure described in Example 8, 3,6-dioxaoctane-1,8-dithiol (0.72 g, 1 eq.) in 1,3-dioxolane (10 mL), lithium hydroxide monohydrate (0.33 g, 2 eq.) .) and sulfur (1.02 g, 8 eq.) gave lithium 3,6-dioxaoctane-1,8-polythiolate in 1,3-dioxolane as a dark red solution.

Example 10 - Synthesis of lithium n-dodecylpolythiolate by lithium alkyl mercaptide

To a nitrogen-degassed slurry of lithium n-dodecyl mercaptide (0.21 g, 1 eq.) in 1,3-dioxolane (5 mL) was added sulfur (0.13 g, 4 eq.). The mixture was stirred at room temperature under nitrogen for 16 hours. Insoluble solids were removed by filtration. As confirmed by LCMS, the dark red filtrate contained 63% lithium n-dodecyl polythiolate and 37% mixture of bis(n-dodecyl)polysulfide.

Example 11 - Synthesis of lithium n-dodecylpolythiolate by lithium metal and sulfur

To a nitrogen-degassed solution of n-dodecyl mercaptan (2.23 g, 1 eq.) in 1,3-dioxolane (25 mL) was added sulfur (1.41 g, 4 eq.) and lithium (76.5 mg). The mixture was heated to 60°C and stirred at 60°C under nitrogen for 1 hour. Lithium n-dodecyl polythiolate in 1,3-dioxolane was obtained as a dark red solution. Whether n-dodecyl mercaptan was completely converted was confirmed by ¹³ C-NMR.

Example 12 - Synthesis of lithium 3,6-dioxaoctane-1,8-polythiolate by lithium metal and sulfur

Following the procedure of Example 11, 3,6-dioxaoctane-1,8-dithiol (1.97 g, 1 eq.), lithium metal (0.15 g, 2 eq.) in 1,3-dioxolane (11 mL), and Reaction with sulfur (2.77 g, 8 eq.) gave a dark red solution of lithium 3,6-dioxaoctane-1,8-polythiolate in 1,3-dioxolane. Complete conversion of the starting dimercaptan was confirmed by ¹³ C-NMR.

Example 13 - Dissolution of Li ₂ S with added lithium n-dodecylpolythiolate

To determine the solubility of lithium sulfide in an electrolyte containing lithium n-dodecylpolythiolate, a saturated solution of lithium sulfide was prepared as follows:

A 0.4M solution of lithium n-dodecylpolythiolate in 1,3-dioxolane was prepared according to the procedure described in Example 10. The solution was then diluted to 0.2M with tetraethylene glycol dimethylether and then added to a 1M LiTFSI solution in 1:1 tetraethylene glycol dimethylether:1,3-dioxolane (1:1 = v/v). To the resulting solution, lithium sulfide was added until a saturated mixture was obtained. The mixture was then filtered and the filtrate was analyzed for dissolved lithium using ICP-MS (Agilent 7700x ICP-MS). The solubility of lithium sulfide was calculated based on the lithium level. The solubility of lithium sulfide in 0.5 M LiTFSI containing 0.1 M lithium n-dodecylpolythiolate in 1:1 tetraethylene glycol dimethyl ether:1,3-dioxolane was determined to be 0.33% by weight. On the other hand, when lithium n-dodecylpolythiolate was not contained, the solubility of lithium sulfide in 0.5M LiTFSI was only 0.13% by weight. This clearly demonstrated that the presence of the organic sulfur of the present invention improves the solubility of Li ₂ S in the electrolyte matrix of the battery.

Example 14 - Preparation of batteries containing organosulfur species-treated anodes

This example illustrates the fabrication of a battery cell with an anode exposed to an electrolyte containing organosulfur species in accordance with one aspect of the invention. Elemental sulfur was combined with conductive carbon and polyethylene (as a binder) in a mass ratio of 75:20:5 (sulfur:carbon:polyethylene) and ball milled to form a chloroform-containing slurry. The slurry was then blade-cast onto carbon-coated aluminum foil and air dried to obtain a sulfur loading of approximately 0.5 mg/cm2. The resulting cathode was then assembled into a CR2032 coin cell equipped with a polypropylene separator and a lithium foil anode in an argon-filled glove box. Each of the electrolytes used contained 0.38 M lithium bis(trifluoromethane)sulfonamide and 0.38 M lithium nitrate in a 1:1 v/v mixture of 1,3-dioxolane and 1,2-dimethoxyethane. One electrolyte (according to the invention) is 100mM 3,6-dioxaoctane-1,8-dithiol di-lithium salt (LiS—C ₂ H ₄ -OC ₂ H ₄ -OC ₂ H ₄ -SLi)( The lithium foil anode is thus brought into contact with 3,6-dioxaoctane-1,8-dithiol di-lithium salt) and the remaining electrolyte (cathode) does not contain any organosulfur species. Battery cycling was performed at 40°C, from 1.7V to 2.6V in the battery test at C/2 for active sulfur. The observed results are shown in Figure 2.

Claims (25)

An anode of an electrochemical cell comprising an anode active material comprising sodium, lithium, potassium or magnesium, or an alloy or complex of one or more of sodium, lithium, potassium or magnesium with one or more other metals to provide ions. , the anode is pretreated with one or more organosulfur species prior to assembly of the electrochemical cell, and the one or more organosulfur species is an organic polysulfide of the formula R ¹ -SS _n -R ² wherein R ¹ and R ² C ₁ which may independently be linear, branched, or cyclic aliphatic or aromatic and may optionally contain one or more functional groups containing N, O, P, S, Se, Si, Sn, halogen and/or metal. -C ₂₀ represents an organic moiety, n is an integer greater than 1), organic thiolate of formula R ¹ -SM and organic polythiolate of formula R ¹ -SS _n -M, where R ¹ is linear, branched , or a C ₁ -C ₂₀ organic moiety, which may be cyclic aliphatic or aromatic and optionally contains one or more functional groups containing N, O, P, S, Se, Si, Sn, halogen and/or metal, and M is lithium, sodium, quaternary ammonium, or quaternary phosphonium, and n is an integer greater than or equal to 1. The anode of an electrochemical cell according to claim 1, wherein the organosulfur species is a dithioacetal or dithioketal of formula (I) or (II) or a trithio-orthocarboxylate of formula (III):

where each R ³ may independently be H, or may be linear, branched, or cyclic aliphatic or aromatic and may contain one or more functionalities containing N, O, P, S, Se, Si, Sn, halogen and/or metal. is a C ₁ -C ₂₀ organic moiety which may optionally contain the group, o, p and q are each independently an integer of 1 or more, and each Z is independently linear, branched, or cyclic aliphatic or aromatic. C ₁ -C ₂₀ organic moieties, which may optionally include one or more functional groups containing N, O, P, S, Se, Si, Sn, halogens and/or metals; Li; Na; quaternary ammonium; or quaternary phosphonium. 2. The method of claim 1, wherein the organosulfur species is an aromatic polysulfide of formula (IV), a polyether-polysulfide of formula (V), a polysulfide-acid salt of formula (VI), or a polysulfide of formula (VII) Sulfide-acid salt, anode of electrochemical cell:

wherein in formula (IV) having an aromatic ring optionally substituted at one or more positions with a substituent other than hydrogen, R ⁴ is independently tert-butyl or tert-amyl, R ⁵ is independently OH, OLi or ONa, r is at least 0, in formula (VI) R ⁶ is a divalent organic moiety, in formula (VII) R ⁷ is a divalent organic moiety, and each Z is independently a C ₁ -C ₂₀ organic moiety , Li, Na or quaternary ammonium, and o and p are each independently an integer of 1 or more. 2. The method of claim 1, wherein the organosulfur species is an organic- or organo-metallic polysulfide containing a trithiocarbonate functionality of formula (IX), an organic- or organo-metallic polysulfide containing a dithiocarbonate functionality of formula (X). Anode of an electrochemical cell, which is a metal polysulfide, or an organic- or organo-metal polysulfide containing a monothiocarbonate function of formula (XI):

Here, Z is a C ₁ -C ₂₀ organic moiety, Na, Li, quaternary ammonium or quaternary phosphonium, and o and p are each independently an integer of 1 or more. 2. The method of claim 1, wherein the organic moiety contains two or more carbon atoms, and the pretreatment with the one or more organosulfur species comprises spraying a solution of the organosulfur species onto the anode or spraying the anode with a solution of the organosulfur species. Anode of an electrochemical cell, performed by immersing in a solution. 2. The electrochemical cell of claim 1, wherein the organic moiety is an oligomer or polymer and the organosulfur species comprises one or more -S-S- linkages pendant to the main chain of the oligomeric or polymeric organic moiety. Anode. 2. The anode of an electrochemical cell according to claim 1, wherein the organic moiety is an oligomer or polymer and the organosulfur species comprises one or more -S-S- linkages incorporated into the backbone of the oligomeric or polymeric organic moiety. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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