Macromonomers and solid polymer electrolytes

Abstract

The present invention provides a macromonomer, an electrolyte precursor composition containing the macromonomer, a method for preparing a solid polymer electrolyte, a solid polymer electrolyte, a solid lithium secondary battery, an electrochemical device, and a device.

Description

[Technical Field]

[0001] The present invention relates to polymer electrolytes that are particularly useful in solid-state lithium-ion batteries. [Background technology]

[0002] In solid-state batteries, the solid electrolyte functions as both the separator and the electrolyte. To function as a separator to prevent short-circuiting between the anode and cathode, the solid electrolyte must have high ionic conductivity to shuttle lithium ions between the cathode and anode at room temperature, while also being mechanically stable.

[0003] Zhang, X.; Daigle, J.C.; Zaghib, K. Comprehensive review of polymer architecture for all-solid-state lithium rechargeable batteries. Materials (Basel). 2020, 13, 2488 summarizes the influence of polymer architecture on the physical and electrochemical properties of SPEs in lithium solid polymer batteries. This discussion focuses primarily on four major categories: linear, comb-type, hyperbranched, and crosslinked polymers. Three main issues remain for PEO-based SPEs to be resolved: low ionic conductivity at low temperatures, low transport numbers, and a relatively narrow electrochemical window when high-voltage cathodes are used.

[0004] Nair, JR, Destro, M., Gerbaldi, C. et al., "Novel multiphase electrode / electrolyte composites for the next generation of flexible polymeric Li-ion cells." J Appl Electrochem 43, 137-145 (2013) describes a methacrylic polymer electrolyte formed in situ directly at the interface of different electrode films (i.e., commercial graphite and hydrothermally synthesized LiFePO4). The polymer electrolyte was prepared under UV irradiation using materials including bisphenol A ethoxylate (15 EO / phenol) dimethacrylate (BEMA), a methacrylic bifunctional oligomer with an average molecular weight of 1,700, and poly(ethylene glycol) methyl ether methacrylate (PEGMA-475, average Mn: 475). Upon exposure to UV irradiation, polymer electrolyte membranes obtained by copolymerizing a reactive mixture containing BEMA, PEGMA-475, LiTFSI, and ECDEC (1:1 w / w) solution along with a photoinitiator were found to be transparent, self-supporting, flexible, non-sticky, and easy to handle.

[0005] Michiyuki Kono et al. (1998) J. Electrochem. Soc. 145 1521 discloses a polymer electrolyte. To prepare the electrolyte, the terminal hydroxyl groups of poly(ethylene oxide-co-propylene oxide) triol (MW 7940) were partially methylated, and the remaining hydroxyl groups were esterified with acrylic acid. The resulting macromonomer was crosslinked by light irradiation in the presence of an electrolyte salt to produce a network polymer electrolyte. However, the electrochemical and mechanical performance needed further improvement.

[0006] St-Onge, V., Cui, M., Rochon, S. et al., "Reducing crystallinity in solid polymer electrolytes for lithium-metal batteries via statistical copolymerization." Commun Mater 2, 83 (2021) discloses an EO-PO polyether copolymer alcohol exhibiting high ionic conductivity. The prepared copolymer contains approximately 300 EO units and a small number of comonomer units. It was discovered that approximately 26 mol% comonomer is sufficient to completely eliminate polymer crystallinity, resulting in a PEO-rich material that cannot be thermodynamically crystallized. A statistical copolymer containing 18 mol% comonomer with 18 wt% LiTFSI is completely devoid of crystallinity. In contrast to the nature of the comonomer side chain, comonomer content strongly influences ionic conductivity. Low amounts of comonomer decrease the crystallite size and crystallinity content. As a result, the addition of only 10 mol% comonomer reduces ionic conductivity by 5 × 10. -8 to 0.3 × 10 -4 S cm -1 The comonomer grows to Li + Introducing large amounts of comonomer into SPEs reduces conductivity because it is not as efficient as EO units in dissolving and complexing salts. Therefore, 10 mol% of comonomer units in the copolymer is the best compromise between reducing crystallinity and increasing the EO content required for ionic conductivity. These copolymers have crystalline contents of 19%, 12%, and 4%, and T gThe temperatures were -44°C, -50°C, and -72°C for the PO, BO, and TO units, respectively. After copolymerization, the copolymer was precipitated with 600 mL of hexane and filtered. The precipitated polymer was dried under vacuum at room temperature for 24 hours to yield a white to yellowish powder. The polymer electrolyte was prepared as follows: 820 mg of polymer was dissolved in 5–10 mL of anhydrous THF in a nitrogen-filled glove box. 180 mg of LiTFSI was then added to the solution and dissolved at 65°C. The solvent was then evaporated under reduced pressure and the solution was dried under vacuum for 24 hours. The electrolyte was kept in the nitrogen glove box. However, the polymer electrolyte prepared using the copolymer alcohol exhibited poor mechanical performance.

[0007] U.S. Patent No. 6,933,078 B2 discloses crosslinked polymer electrolytes containing poly(ethylene glycol) methyl ether methacrylate (POEM) monomers crosslinked to a second monomer with a low Tg. Crosslinked polymer electrolytes such as POEM-X-PDMSD-LiN(CF3SO2)2 and POEM-X-PDMSM-PEGDME-LiN(CF3SO2)2 are disclosed. While U.S. Patent No. 6,933,078 B2 does not disclose the preparation of POEM-X-PDMSM-PEGDME-LiN(CF3SO2)2, it does mention that "PDMSM can be easily grafted to POEM monomers, while PDMSD can be easily crosslinked with POEM monomers using free-radical synthesis methods. (PDMSM crosslinked polymers can be prepared using alternative synthesis methods.) POEM-g-PDMSM polymers are soluble electrolytes with relatively low conductivity and poor mechanical properties." Example 4 discloses the preparation of POEM-X-PDMSD-LiN(CFSO) using POEM (14.8 ml), methacryloxypropyl-terminated polydimethylsiloxane (PDMSD) (4.0 ml), ethyl acetate (96 ml), LiN(CFSO) (1.8 g), and adding AIBN (0.072 g) by solution casting. The patent does not disclose the specific mechanical properties of the crosslinked polymer electrolyte prepared in the examples.

[0008] U.S. Patent Application Publication No. 20030180624A1 discloses an interpenetrating network solid polymer electrolyte comprising at least one branched siloxane polymer having one or more poly(alkylene oxide) branches as side chains, at least one crosslinker, at least one monofunctional monomer compound for controlling crosslink density, at least one metal salt, and at least one radical initiator. In Examples 1 and 2, SPEs are prepared using 0.4 to 2.0 g of the branched siloxane polymer, 0.4 g of poly(ethylene glycol-600) dimethacrylate (PEGDMA600), and 1.2 to 1.6 g of poly(ethylene glycol) ethyl ether methacrylate (PEGEEMA). During preparation, a porous polycarbonate membrane is used as the support for the IPN SPE. Both IPN SPEs are heated at room temperature for 10 minutes. -5 It exhibits high ionic conductivity exceeding S / cm, and the ionic conductivity increases as the content of branched siloxane polymer increases.

[0009] Summary of the Invention The present invention aims to solve at least some of the problems in the art. The present invention aids in the production process of solid polymer electrolytes by using a liquid starting formulation that can be crosslinked and solidified during solid-state battery production. This is achieved by using (meth)acrylate monomers with amorphous side chains that inhibit crystallization. Furthermore, polymer electrolytes using (meth)acrylate monomers crosslinked with siloxane monomers have achieved surprisingly good mechanical performance and surprisingly high ionic conductivity at low temperatures, such as below 40°C, especially below 20°C.

[0010] By designing polyether-copolymer (meth)acrylate macromonomers, the mechanical properties of the polymer relative to its molecular weight can be tailored by polymerization, where crosslinking agents are used to tailor the elastic properties of the resulting elastomeric material.

[0011] The present invention provides a macromonomer represented by the following general formula (I): [ka] wherein R1 represents methyl or H; In the formula, z is the number of repeats of the ethylene glycol spacer and represents 0, 1, 2, or 3; R2 represents methyl or a C2-C10 aliphatic or aromatic group, preferably methyl or ethyl, more preferably methyl; n represents a positive integer of 10 to 200, preferably 10 to 100, more preferably 40 to 80; n defines the degree of polymerization of a random copolymer having a ratio of comonomers x and y; and A macromonomer is provided in which y=1% to 40%, preferably 5% to 25%, more preferably 10% to 20%, and even more preferably 12% to 18%, and x=1-y.

[0012] The number average molecular weight of the macromonomer is typically 500 to 10,000, preferably 500 to 5,000, for example, 600 to 4,500, more preferably 750 to 4,000, or 750 to 2,000, even more preferably 800 to 1,500, for example, about 1,000.

[0013] Preferably, the macromonomer is liquid at room temperature. Such liquid macromonomers have the formula (I): R1 represents methyl or H; z is the number of repeats of the ethylene glycol spacer and is 0, 1, 2, or 3; R2 represents methyl or a C2-C5 aliphatic group, preferably methyl or ethyl, more preferably methyl; n represents a positive integer from 10 to 100; n defines the degree of polymerization of a random copolymer having a ratio of comonomers x and y; y=10% to 25%, preferably 14% to 20%, x=1-y; and The number average molecular weight of the macromonomer is 500 to 5,000, preferably 750 to 2,000, more preferably 800 to 1,500, for example, about 1,000.

[0014] The macromonomer is a poly(ethylene glycol-co-propylene glycol) alkyl ether (meth)acrylate.

[0015] The macromonomer of the present invention does not have crystalline domains. In other words, the polyether-copolymer (meth)acrylate macromonomer is amorphous. The macromonomer is anhydrous. It is a liquid at room temperature. Therefore, no solvent is required to handle it, and it does not need to be removed after the reaction, so it can be used as a reactive diluent for formulations that does not produce volatile organic compounds (VOCs).

[0016] Furthermore, the macromonomers of the present invention can be used to prepare electrolytes with good electrochemical performance, such as high ionic conductivity, especially at low temperatures, and good mechanical performance, such as mechanical stability or strength.

[0017] The present invention further provides a polymerizable composition comprising the macromonomer of the present invention and less than 5 wt%, for example less than 4 wt%, less than 3 wt%, less than 2 wt%, preferably less than 1 wt%, for example less than 0.9 wt%, less than 0.8 wt%, less than 0.7 wt%, less than 0.6 wt%, less than 0.5 wt%, less than 0.4 wt%, less than 0.3 wt%, less than 0.2 wt%, or even less than 0.1 wt%, of a solvent based on the total weight of the macromonomer composition; The number average molecular weight of the macromonomer is 500 to 5,000, preferably 750 to 2,000, and more preferably 800 to 1,500. A macromonomer composition is provided.

[0018] The macromonomer composition is a liquid at room temperature.

[0019] The solvent may include water and suitable organic solvents such as alcohols, esters, ethers, ketones, and the like.

[0020] The amount of macromonomer is typically greater than 90 wt%, preferably greater than 95 wt%, e.g., greater than 96 wt%, 97 wt%, 98 wt%, more preferably greater than 99 wt%, e.g., greater than 99.1 wt%, 99.2 wt%, 99.3 wt%, 99.4 wt%, 99.5 wt%, 99.6 wt%, 99.7 wt%, 99.8 wt%, or 99.9 wt%, based on the total weight of the macromonomer composition.

[0021] The macromonomer of formula (I) can be synthesized via transesterification, direct esterification with (meth)acrylic acid, or esterification with activated (meth)acrylic acid derivatives such as (meth)acrylic anhydride or (meth)acrylic acid chloride. Amorphous monomers can be synthesized using procedures (or slight modifications thereof) known in the art, such as those described in International Publication No. WO2010003710A1 or International Publication No. WO2020035315A1 or European Patent No. EP0780360B1.

[0022] In some embodiments, the method for preparing the macromonomer of the present invention comprises the steps of: I) reacting a primary alcohol with ethylene oxide (EO) and propylene oxide (PO) under catalysis; and II) reacting the reaction product of step I) with a (meth)acrylate in the presence of a catalyst to obtain a macromonomer.

[0023] The macromonomer is an amorphous poly(ethylene glycol-co-propylene glycol) alkyl ether (meth)acrylate.

[0024] One skilled in the art can adjust the molar ratio of EO to PO and the molar ratio of EO and PO to primary alcohol to obtain a macromonomer having the desired repeat units and molecular weight.

[0025] The primary alcohol may be any monofunctional alcohol. For example, the monofunctional alcohol may be selected from methanol, methyl diglycol, methyl glycol, methyl triglycol, methoxypolyethylene glycol (MPEG), and other polar monofunctional alcohols.

[0026] In some embodiments, the method for preparing the macromonomer of the present invention comprises the steps of: I) reacting a primary alcohol with ethylene oxide and propylene oxide to obtain a polyether; and II) reacting the polyether with methyl (meth)acrylate to obtain poly(ethylene glycol-co-propylene glycol) methyl ether (meth)acrylate; Includes:

[0027] The present invention further comprises: A) the macromonomer of the present invention; B) siloxane monomers, especially acrylate-functional siloxane monomers; and C) a lithium salt, and optionally D) Free Radical Initiators The present invention provides an electrolyte precursor composition (i.e., electrolyte formulation) comprising:

[0028] The lithium salt and free radical initiator (which may be irradiative or thermal) may be selected from those conventional in the art.

[0029] The electrolyte precursor composition may be free of any solvent, including water and organic solvents. The electrolyte precursor composition preferably contains less than 10 wt%, e.g., less than 9 wt%, less than 8 wt%, less than 7 wt%, less than 6 wt%, more preferably less than 5 wt%, e.g., less than 4 wt%, less than 3 wt%, less than 2 wt%, even more preferably less than 1 wt%, e.g., less than 0.9 wt%, less than 0.8 wt%, less than 0.7 wt%, less than 0.6 wt%, less than 0.5 wt%, less than 0.4 wt%, less than 0.3 wt%, less than 0.2 wt%, or even less than 0.1 wt%, based on the total weight of the electrolyte precursor composition. In some embodiments, the electrolyte precursor composition does not contain an organic solvent or water.

[0030] The electrolyte precursor composition may further include a filler. Examples of fillers may include silicon oxide and metal oxide.

[0031] Thus, the present invention provides a liquid electrolyte precursor formulation that can be used to produce a solid electrolyte for a solid-state battery. After coating the formulation onto an electrode, the liquid formulation can be solidified.

[0032] The present invention further comprises: a) providing an electrolyte precursor composition of the present invention; and b) crosslinking the liquid electrolyte precursor composition by irradiation or heat treatment in the presence of a free radical initiator. The present invention provides a method for preparing a solid polymer electrolyte, comprising:

[0033] The methods of irradiation (eg, UV, electron) and heat treatment may be conventional.

[0034] The present invention further provides a solid polymer electrolyte prepared according to the method of the present invention or obtained by curing an electrolyte precursor composition.

[0035] The electrolyte may be free of any solvent, including water and organic solvents, and is preferably free of any solvent, including water and organic solvents.

[0036] Transparent and elastic films can be obtained by the method of the present invention. The electrolyte exceeds the PEO SPE benchmark, especially at low temperatures.

[0037] The present invention further provides a lithium ion battery comprising a solid polymer electrolyte according to the present invention.

[0038] The present invention further provides a solid-state lithium secondary battery comprising a cathode, a solid copolymer electrolyte according to the present invention, and an anode, preferably a lithium metal anode, which does not include a separator as used in liquid lithium secondary batteries.

[0039] The present invention further provides a method for preparing a solid state lithium secondary battery, comprising the steps of: A method is provided which includes assembling a cathode, a solid copolymer electrolyte according to the present invention, and an anode, preferably a lithium metal anode, to form a solid state lithium secondary battery.

[0040] In the present invention, the term "solid polymer electrolyte" refers to an all-solid polymer electrolyte and / or a quasi-solid polymer electrolyte. The solid polymer electrolyte in the present invention is preferably an all-solid polymer electrolyte. When referring to the solid polymer electrolyte of the present invention, the term "copolymer electrolyte" is used interchangeably with "polymer electrolyte" unless otherwise specified.

[0041] In the present invention, the term "lithium secondary battery" includes lithium ion secondary batteries and lithium metal secondary batteries.

[0042] The present invention further provides an electrochemical device comprising a solid polymer electrolyte according to the present invention.

[0043] In some examples, the electrochemical device is a secondary battery, such as a lithium ion battery, particularly a lithium metal secondary battery.

[0044] The present invention further provides devices comprising the electrochemical device according to the present invention, including, but not limited to, electric vehicles, electrical appliances, power tools, portable communication devices such as mobile phones, consumer electronic products, and any other products suitable for incorporating the electrochemical device or lithium secondary battery of the present invention as an energy source.

[0045] The present invention further provides the use of the macromonomer according to the present invention, or the use of the electrolyte precursor composition according to the present invention, in the preparation of a solid polymer electrolyte in a lithium secondary battery, in particular a lithium metal secondary battery, for improving performance such as the mechanical properties of the electrolyte, in particular the ionic conductivity at low temperatures such as 0 to 40°C, in particular 0 to 20°C, for example 0 to 10°C, and / or the cycling performance.

[0046] Siloxane Monomer The siloxane monomer is selected from organically modified siloxanes having an ethylenically unsaturated radically polymerizable group. The ethylenically unsaturated radically polymerizable group is preferably selected from (meth)acryloxy functional groups. The siloxane monomer is preferably selected from (meth)acryloxy functionalized siloxanes having an ethylenically unsaturated radically polymerizable group. The acryloxy functional group is required for effective crosslinking.

[0047] The number of radically polymerizable groups in the siloxane monomer is typically 3 or more to ensure effective crosslinking.

[0048] The siloxane monomer is preferably selected from (meth)acryloxy-functionalized siloxanes having 4 to 40 silicon atoms, with 15% to 100% of the silicon atoms having an ethylenically unsaturated radically polymerizable group.

[0049] In some embodiments, the siloxane monomer further comprises an ester group that is not radically polymerizable.

[0050] In some embodiments, the siloxane monomer is a compound of formula (II):

[0051] M 1 e M 3 f D 1 g D 3 h (II) During the ceremony, M 1 =[R 1 3SiO 1 / 2 ] and M 3 =[R 1 2nd Round 3 SiO 1 / 2 ] and D 1 =[R 1 2SiO 2 / 2 ] and D 3 =[R 1 R 3 SiO 2 / 2 ] and e=0~2, f=0 to 2, preferably 0, and e+f=2; g=0 to 38, preferably 10 to 26; h=0 to 20, for example, 1 to 20, or 2 to 20, or 3 to 20, preferably 4 to 15; the ratio of the sum (f+h) to the sum (g+h+2) is 0.15 to a maximum of 1, preferably 0.2 to 0.5; The sum (g+h+2) is 4 to 40, preferably 10 to 30, R 1 are the same or different aliphatic hydrocarbons having 1 to 10 carbon atoms or aromatic hydrocarbons having 6 to 12 carbon atoms, preferably methyl and / or represents a phenyl group, particularly preferably a methyl group, R 3represents the same or different hydrocarbons having 1 to 5 identical or different ester, preferably (meth)acryloxy functional groups, the hydrocarbons being linear, cyclic, branched and / or aromatic, preferably linear or branched, and the ester, preferably (meth)acryloxy functional groups, being selected from ethylenically unsaturated radically polymerizable esters, preferably (meth)acryloxy functional groups, and ester groups that are not radically polymerizable.

[0052] R 3 The ester functional group is preferably a (meth)acryloxy functional group.

[0053] Preferably, in the siloxane monomer, the radically polymerizable groups are present in a number fraction of between 80 and 90% based on the number of all ester functional groups in the compound of formula (II).

[0054] The radical R in the compound of formula (II) 3 The ethylenically unsaturated radically polymerizable ester functional groups are preferably selected from acrylic and / or methacrylic acid ester functional groups, more preferably acrylic acid ester functional groups.

[0055] The radical R in the compound of formula (II) 3 The radically non-polymerizable ester groups are preferably monocarboxylic acid radicals. The radically non-polymerizable ester groups are preferably selected from the acid radicals of acetic acid, propionic acid, butyric acid, valeric acid, and benzoic acid, more preferably acetic acid. More preferably, the monocarboxylic acid radicals are present in a number fraction of 3% to 20%, preferably 5% to 15%, based on the number of all ester functional groups in the compound of formula (II).

[0056] In some preferred embodiments, the siloxane monomer is a compound of formula (II), wherein: e=2, f=0, h=4~15, The sum (g+h+2) is 5 to 40, preferably 10 to 30, R 3 represents the same or different hydrocarbons having 1 to 5 identical or different esters, the hydrocarbons being linear, cyclic, branched and / or aromatic, preferably linear or branched, and the esters being ethylenically unsaturated, radically polymerizable esters, preferably (meth)acryloxy functional groups, and (meth)acryloxy functional groups selected from ester groups that are not radically polymerizable; and The number of radically polymerizable groups in the siloxane monomer is 3 or more.

[0057] Organomodified silicones can be prepared by the processes described in US Pat. No. 10,465,032 B2 or US Pat. No. 4,978,726.

[0058] A preferred example of the siloxane monomer may be TEGOMER® V-Si 7255, commercially available from Evonik Industries AG.

[0059] TEGOMER® V-Si 7255 is a comb-type acryloxy-functional polysiloxane. Chemical names are siloxane and silicone, 3-[3-(acetyloxy)-2-hydroxypropoxy]propyl Me, di-Me, 3-[2-hydroxy-3-[(1-oxo-2-propen-1-yl)oxy]propoxy]propyl Me. CAS number: 125455-51-8.

[0060] Preferably, the weight ratio of siloxane monomer to macromonomer of the invention is 1:0.4 to 1:80, in particular 1:0.8 to 1:52, preferably 1:1.6 to 1:55, in particular 1:1.6 to 1:52, more preferably 1:12.8 to 1:55, even more preferably 1:20 to 1:52, in particular 1:12.8 to 1:52.

[0061] lithium salts A lithium salt is a material that dissolves in a non-aqueous electrolyte to dissociate lithium ions.

[0062] The lithium salt can be any conventionally used in the art, but is thermally stable during in situ polymerization (e.g., at 80° C.), and non-limiting examples include lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium difluorooxalatoborate (LiODFB), LiAsF, LiClO, LiN(CFSO), LiBF, LiSbF, and LiCl, LiBr, LiI, LiB 10 Cl 10 The lithium salt may be at least one selected from the group consisting of LiCF3SO3, LiCF3CO2, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, lithium chloroborane, lithium lower aliphatic carboxylate, lithium tetraphenylborate, and imides. The lithium salt is preferably selected from LiTFSI, LiFSI, and LiClO4. These materials may be used alone or in any combination.

[0063] Free Radical Initiators The free radical initiator of the polymerization reaction may be conventional in the art, for example for irradiation, such as thermal or photopolymerization of reactive monomers.

[0064] Examples of free radical initiators or polymerization initiators include azo compounds such as 2,2-azobis(2-cyanobutane), 2,2-azobis(methylbutyronitrile), 2,2'-azoisobutyronitrile (AIBN), and azobisdimethylvaleronitrile (AMVN), peroxy compounds such as benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumyl peroxide, and hydrogen peroxide, and hydroperoxides. Preferably, AIBN, 2,2'-azobis(2,4-dimethylvaleronitrile) (V65), and di-(4-tert-butylcyclohexyl)peroxydicarbonate (DBC) are used.

[0065] Preferably, the free radical thermal initiator may be selected from azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), benzoyl peroxide (BPO), lauroyl peroxide (LPO), etc. More preferably, the free radical initiator is benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN).

[0066] Free radical photoinitiators generate free radicals when exposed to UV light, and then initiate polymerization. Examples of photoinitiators include benzoyl compounds, such as 2,2-dimethoxy-1,2-diphenyl-ethan-1-one (DMPA), benzil dimethyl ketal, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 2-hydroxy-2-methylpropiophenone (HMPP), 1-hydroxycyclohexylphenyl ketone (HCPK), and the like, which can be used.

[0067] Preferably, the free radical photoinitiator may be selected from 2,2-dimethoxy-1,2-diphenyl-ethan-1-one (DMPA), benzil dimethyl ketal, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), etc. More preferably, the free radical photoinitiator is 2,2-dimethoxy-1,2-diphenyl-ethan-1-one (DMPA).

[0068] The amount of free radical initiator is conventional. Preferably, the amount of free radical initiator is 0.1 to 3 wt. %, more preferably about 0.5 wt. %, based on the total weight of the monomers of the copolymer.

[0069] In some embodiments, the amount of photoinitiator or thermal initiator can be 0.2% to 2% by weight, preferably about 0.5% by weight, based on the total weight of the macromonomer and siloxane monomer of the present invention. Photoinitiators or thermal initiators generate free radicals to initiate polymerization under UV irradiation or heat.

[0070] In some embodiments, the polymerization initiator decomposes at a specific temperature between 40 and 80°C to form radicals that can react with monomers to form polymer electrolytes via free radical polymerization. Generally, free radical polymerization occurs through a sequence of reactions: initiation, which involves the formation of transient molecules with highly reactive or active sites; propagation, which involves the reformation of active sites at the ends of the chains by the addition of monomers to the active chain ends; chain transfer, which involves the transfer of active sites to other molecules; and termination, which involves the destruction of the active chain center.

[0071] Preferably, the solid-state lithium secondary battery may be a coin battery or a pouch battery.

[0072] The electrochemical device encompasses any type of device that undergoes an electrochemical reaction. Examples of the electrochemical device include any type of primary battery, secondary battery, fuel cell, solar cell, capacitor, etc., and preferably a secondary battery.

[0073] Generally, secondary batteries are made by incorporating an electrolyte into an electrode assembly consisting of a cathode and an anode, the cathode and anode facing each other with or without a separator between them.

[0074] The cathode is prepared by, for example, applying a mixture of a cathode active material, a conductive material, and a binder to a cathode current collector, followed by drying and pressing. If necessary, a filler may be added to the mixture.

[0075] The cathode current collector is typically fabricated to a thickness of 3 to 500 μm. There is no particular limitation on the material of the cathode current collector, as long as it has high conductivity without causing chemical changes in the fabricated battery. Examples of materials for the cathode current collector include stainless steel, aluminum, nickel, titanium, sintered carbon, and aluminum or stainless steel surface-treated with carbon, nickel, titanium, or silver. The current collector may be fabricated with micro-irregularities on its surface to enhance adhesion to the cathode active material. Additionally, the current collector may take various forms, such as a film, sheet, foil, net, porous structure, foam, or nonwoven fabric.

[0076] Examples of cathode active materials that can be used in the present invention include layered compounds such as lithium cobalt oxide (LiCoO) and lithium nickel oxide (LiNiO), or LiNi x Co y Mn 1-x-y (NCM); compounds of the formula Li 1+x Mn 2-x O4 (0≦x≦0.33), lithium manganese oxides such as LiMnO3, LiMn2O3 and compounds of LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5 and Cu2V2O7; compounds of the formula LiNi 1-x M x Ni-site type lithium nickel oxide of O2 (M=Co, Mn, Al, Cu, Fe, Mg, B or Ga and 0.01≦x≦0.3); formula LiMn 2-x M x Lithium manganese composite oxides of the formula LiMnO2 (M=Co, Ni, Fe, Cr, Zn, or Ta, and 0.01≦x≦0.1), or Li2Mn3MO8 (M=Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which a portion of the Li is replaced with an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3, LiFe3O4, etc., may be used, but are not limited to these.

[0077] In some embodiments, the cathode active material is LiFePO4, LiCoO2, LiNi 0.8 Mn0.1 Co 0.1 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.85 Co 0.05 Al 0.1 O2, all of which are commercially available common cathodes.

[0078] In some embodiments, the cathode slurry is obtained by blending the cathode active material, super-p, binder, and lithium perchlorate (LiClO) in a solvent, and then the slurry is directly loaded onto an aluminum foil by blade casting and dried under vacuum to remove the solvent. In some embodiments, the weight ratio of the cathode active material, super-p, binder, and LiClO is (67%-89%):(5%-20%):(5%-10%):(1%-3%).

[0079] Preferably, the weight ratio of the cathode active material, super-p, binder, and LiClO4 is 78.94%:9.87%:9.87%:1.32%.

[0080] The solvent used in preparing the cathode slurry is preferably acetonitrile or N-methylpyrrolidone. Typically, acetonitrile is used when the binder is PEO, and N-methylpyrrolidone is used when the binder is PVDF.

[0081] Preferably, the temperature of the dried cathode slurry is 60° C. to 120° C. The time for drying the cathode slurry may be preferably 10 to 24 hours, more preferably 12 hours.

[0082] The conductive material is typically added in an amount of 1 to 50% by weight based on the total weight of the mixture containing the cathode active material. The conductive material is not particularly limited, as long as it has adequate conductivity without causing chemical changes in the fabricated battery. Examples of conductive materials include conductive materials including graphite, such as natural or artificial graphite; carbon blacks, such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers, such as carbon fiber and metal fiber; metal powders, such as fluorocarbon powder, aluminum powder, and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and polyphenylene derivatives.

[0083] Binders are components that aid in binding the active material to the conductive material and to the current collector. Binders are typically added in amounts of 1-50% by weight, based on the total weight of the mixture including the cathode active material. Examples of binders include polyvinylidene fluoride, poly(ethylene oxide) (PEO), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, and various copolymers.

[0084] In some embodiments, the polymer binder is poly(ethylene oxide) (PEO) or poly(vinylidene fluoride) (PVDF).

[0085] The filler is an optional component used to suppress cathode expansion. The filler is not particularly limited as long as it does not cause chemical changes in the fabricated battery and is a fibrous material. Examples of fillers include olefin polymers such as polyethylene and polypropylene, and fibrous materials such as glass fiber and carbon fiber. The anode is fabricated by applying the anode active material to the anode current collector and then drying it. If necessary, other components such as those described above may be included.

[0086] The anode current collector is typically fabricated to a thickness of 3 to 500 μm. The material of the anode current collector is not particularly limited, as long as it has appropriate conductivity without causing chemical changes in the fabricated battery. Examples of materials for the anode current collector include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, or silver, and aluminum-cadmium alloys. Like the cathode current collector, the anode current collector may also be processed to form micro-irregularities on its surface to enhance adhesion strength with the anode active material. Additionally, the anode current collector may be used in various forms, such as a film, sheet, foil, net, porous structure, foam, or nonwoven fabric.

[0087] Examples of anode active materials that can be used in the present invention include carbon, such as non-graphitic carbon and graphitic carbon; Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1) and Sn x Me 1-x Me' y O z(Me: Mn, Fe, Pb, or Ge; Me': Al, B, P, Si, Group I, II, and III elements of the periodic table, or halogens; 0≦x≦1; 1≦y≦3; and 1≦z≦8); lithium metal; lithium alloys; silicon-based alloys; tin-based alloys; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; conductive polymers such as polyacetylene; and Li-Co-Ni-based materials. In some examples of the present invention, lithium metal is used as the anode.

[0088] The secondary battery according to the present invention may be, for example, a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, a lithium ion polymer secondary battery, or the like. The secondary battery may be fabricated in various forms. For example, the electrode assembly may be configured in a jelly roll structure, a stacked structure, a stacked / folded structure, or the like. The battery may be configured by placing the electrode assembly in a battery case made of a cylindrical can, a prismatic can, or a laminate sheet including a metal layer and a resin layer. Such battery configurations are widely known in the art.

[0089] Using the macromonomer and electrolyte precursor composition of the present invention, a solid polymer electrolyte with high ionic conductivity and good mechanical stability / strength can be prepared. Furthermore, the macromonomer and electrolyte precursor composition of the present invention is liquid and does not contain water. No solvent is required to handle the macromonomer and electrolyte precursor composition of the present invention. After crosslinking and preparing a solid polymer electrolyte using the electrolyte precursor composition of the present invention, there is no need to remove the solvent.

[0090] Due to the additional cross-linking between the macromonomer and the siloxane monomer, the solid polymer electrolyte of the present invention has much better mechanical performance than prior art polymer electrolytes that use PEO polymers or PEOPO copolymers, particularly at temperatures above the melting point of the PEO polymer or PEOPO copolymer, where mechanical strength decreases.

[0091] In contrast to poly(ethylene oxide) (PEO), the benchmark for solid polymer electrolytes, the solid electrolytes of the present invention lack the ability to crystallize. The completely amorphous structure of the electrolytes of the present invention exhibits excellent ionic conductivity at lower temperatures. This is due to the absence of crystalline domains that hinder ion migration at lower temperatures and the reduced complexation of amorphous poly(ethylene glycol-co-propylene glycol) to the PEG or PEO structure. Furthermore, the comonomer propylene oxide in the polyether side chains of the present invention reduces lithium ion chelation and therefore increases their mobility. In contrast to the state-of-the-art approach involving uncrosslinked polyethers with molecular weights below 15,000 g / mol, which lack mechanical integrity above their melting points, the macromonomers of the present invention with polyether side chains can be polymerized with siloxane monomers to form high molecular weights with much better mechanical properties at such temperatures. Crosslinking with a crosslinker allows for the formation of transparent, highly elastic films that function as both electrolytes and separators in solid-state batteries. Elastic films can withstand deformation, thus improving battery safety.

[0092] The process of the present invention simplifies the production process and allows lithium-ion battery manufacturers to use established equipment for lithium-ion batteries with liquid electrolytes. Compared to the conventional manufacturing process for lithium-ion batteries with liquid electrolytes, in the process of the present invention, the drying step is replaced with a crosslinking step, and the solid electrolyte is formed from a monomer formulation. In addition, the electrolyte filling step is eliminated. Due to the simplified production process, the cost of the cell factory is expected to be 20% lower than that of current factories of equivalent capacity.

[0093] Current battery production involves the use of liquid electrolytes. The formulation described can also be used as a liquid before crosslinking. After application to the battery electrodes, it can be solidified by crosslinking. This simplifies the production process, as no additional solvents or extrusion equipment are required.

[0094] Prepared solid electrolytes with high conductivity at room temperature are useful for enabling electrification of mobility.

[0095] Other advantages of the present invention will be apparent to those skilled in the art upon reading this specification. [Brief explanation of the drawings]

[0096] [Figure 1] 1 shows the ionic conductivities of the crosslinked polymer electrolytes prepared in Examples 1-2 and Comparative Examples 1-3 at different temperatures.

[0097] MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail by the following examples, the scope of which should not be limited to the embodiments of the examples.

[0098] material The following materials were used in the examples:

[0099] VISIOMER® MPEG 1005 MA W represents methoxypolyethylene glycol 1000 methacrylate (50% by weight in water). It is a highly polar monomer (50% by weight in water) with excellent water solubility. The monomer may be represented by the following formula (III): [ka] The molecular weight is 1005. VISIOMER® MPEG 1005 MA W was freeze-dried to remove water and obtain a solid monomer.

[0100] VISIOMER® MPEG 2005 MA W represents methoxypolyethylene glycol 2000 methacrylate (50% by weight in water). It is a highly polar monomer (50% by weight in water) with excellent water solubility. The monomer can be represented by formula (III) above and has a molecular weight of 2005. VISIOMER® MPEG 2005 MA W was lyophilized to remove water and obtain a solid monomer.

[0101] Both VISIOMER® MPEG 1005 MA W and VISIOMER® MPEG 2005 MA W are commercially available from Evonik Industries AG.

[0102] Analysis procedure Electrochemical impedance spectroscopy measurements were performed using an SP-300 potentiostat (BioLogic Science Instruments) in a temperature range between 0 and 70 °C. Impedance measurements were performed at an amplitude of 20 mV over a frequency range of 1 MHz to 500 mHz (and vice versa). The heating cycle involved a stepwise temperature increase of 10 °C steps from 0 °C to 70 °C. The temperature was increased to 60 °C h -1 The temperature was increased at a heating / cooling rate of 0.01 sq. m / s over 10 min, after which the temperature was held constant for another 50 min to acquire the impedance spectra. At a temperature of 70 °C, the heating profile was reversed and the sample was slowly cooled with similar temperature steps. The ionic conductivity σ was calculated according to the following equation: σ=1 / Rb *L / A R b is the bulk electrolyte resistance accessible from the Nyquist plot, L is the film thickness, and A is the film area.

[0103] Example 1 Synthesis of poly(ethylene glycol-co-propylene glycol) ether alcohol (methyl diglycol + 16 EO / 3 PO): In a 17-liter autoclave, 1556 g of methyl diglycol and 45.4 g of potassium methanolate catalyst were added, and the reactor contents were inerted with nitrogen. The stirred reaction mixture was heated to 60°C and stirred for 15 minutes. The internal pressure of the reactor was reduced to 100 mbar, and the reaction mixture was heated to a reaction temperature of 115°C. Over 2.5 hours, a mixture of 9595 g of ethylene oxide and 2370 g of propylene oxide was added with stirring and cooled to a maximum internal temperature of 115°C and an internal pressure of 2.3 bar (abs.). After the addition was complete, the mixture was held at 115°C for 1.5 hours, after which the reaction mixture was degassed. Volatile components, such as residual ethylene oxide and propylene oxide, were removed by distillation under vacuum. The alkaline product was cooled to 90°C and neutralized by the addition of aqueous phosphoric acid, and the mixture was stirred for 30 minutes. 6.78 g of ANOX® 20 (a high molecular weight hindered phenolic antioxidant and primary stabilizer from SI Group) was added as an antioxidant. Water was removed by distillation under reduced pressure (<20 mbar) with the temperature increasing to 110°C. The mixture was cooled to 70°C, and the precipitated phosphate was removed by filtration. The yield of liquid colorless polyether was 13.5 kg. The resulting poly(ethylene glycol-co-propylene glycol) ether alcohol had 56.4 mg KOH / g hydroxyl groups and an acid value of 0.2 mg KOH / g.

[0104] Synthesis of poly(ethylene glycol-co-propylene glycol) methyl ether methacrylate 1000: The poly(ethylene glycol-co-propylene glycol) ether alcohol (4400 g, 4.40 mol, Mw 1000 g / mol) and methyl methacrylate (11013 g, 110.0 mol) prepared above were weighed into a reaction vessel. Hydroquinone monomethyl ether (MEHQ) (0.94 g, 200 ppm relative to the product) was added, and (dilute) air was passed through the reaction mixture. The mixture was dehydrated by azeotropic distillation of water / methyl methacrylate until the initial water was completely removed. The amount of methyl methacrylate removed during dehydration was then replaced by adding the appropriate amount to the mixture. The catalyst titanium tetraisopropoxide (44.0 g, 0.155 mol, 1 wt. % relative to the alcohol) was added, and the mixture was heated to reflux, gradually distilling off the methanol / methyl methacrylate azeotrope. Complete conversion of the starting material was achieved after 3 hours. The mixture was cooled to 60-85°C, and the catalyst was precipitated with dilute sulfuric acid (1 wt%) under constant stirring. After neutralization with Na2CO3 (10 wt%), a filter aid (Celite) was added. Water and a portion of the excess methyl methacrylate were distilled off under vacuum and elevated temperature. The reaction mixture was then filtered using a pressure filtration device, and the residual solvent was removed under vacuum. The product was obtained as a clear liquid. Yield: 4613g (98% by weight). Water content: 0.015 wt % (determined by Karl Fischer titration), GPC analysis was consistent with the expected Mw distribution based on the product and starting materials.

[0105] Preparation of solid polymer electrolyte: The prepared amorphous poly(ethylene glycol-co-propylene glycol) methyl ether methacrylate 1000 (840 mg, 84 wt %, based on the total weight of the reaction mixture) was mixed with TEGOMER® V-Si 7255 (30 mg, 3 wt %), photoinitiator (phenyl-bis-(2,4,6-trimethylbenzoyl)-phosphinoxide, BAPO) (30 mg, 3 wt %), and lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (100 mg, 10 wt %). The mixture was stirred overnight in the dark and then dried at 60 °C overnight. The final material was poured directly onto a stainless steel disk and then exposed to light (TLC, λ = 365 nm) at room temperature for 3 hours.

[0106] Example 2 In Example 2, a poly(ethylene glycol-co-propylene glycol) ether alcohol with twice the molecular weight prepared in Example 1 was prepared using the same method as in Example 1, except that only half the amount of methyl diglycol alcohol and half the amount of potassium methanolate catalyst described in Example 1 was used.

[0107] Synthesis of poly(ethylene glycol-co-propylene glycol) methyl ether methacrylate 2000: The poly(ethylene glycol-co-propylene glycol) ether alcohol (1437.8 g, 0.72 mol, Mw 2000 g / mol) prepared above and methyl methacrylate (3063.5 g, 30.6 mol) were weighed into a reaction vessel. MEHQ (0.297 g, 200 ppm relative to the product) was added, and diluted air was passed through the reaction mixture. Calcium oxide (11.21 g, 200 mmol, 0.78% relative to the alcohol) and lithium chloride (3.16 g, 74.5 mmol, 0.22% relative to the alcohol) were added, and the mixture was heated to reflux while the methanol / methyl methacrylate azeotrope was constantly distilled off. After 4-6 h, complete conversion was achieved, and filter aid (Celite) was added. With stirring, excess methyl methacrylate was distilled off at elevated temperature under vacuum, and the mixture was then filtered using a pressure filtration device. Residual methyl methacrylate was removed under vacuum. The product was obtained as a clear liquid. Yield: 1346 g (91% by weight, loss on filter plate). Water content: 0.01 wt % (determined by Karl Fischer titration), GPC analysis was consistent with the expected Mw distribution based on the product and starting materials.

[0108] Preparation of solid polymer electrolyte: A solid polymer electrolyte was prepared according to the same method as in Example 1, except that amorphous poly(ethylene glycol-co-propylene glycol) methyl ether methacrylate 2000 was used as the starting material.

[0109] Example 3 Synthesis of poly(ethylene glycol-co-propylene glycol) methyl ether methacrylate 4000: Poly(oxyalkylene) ether alcohol (4008.6 g, 1.00 mol, Mw approx. 4068 g / mol) and methyl methacrylate (6019.3 g, 60.12 mol) were weighed into a reaction vessel. MEHQ (0.82 g, 200 ppm relative to the product) was added, and (dilute) air was passed through the reaction mixture. The mixture was dehydrated by azeotropic distillation of water / methyl methacrylate until the water initially present was completely distilled off. The amount of methyl methacrylate distilled off during dehydration was then replaced by adding the appropriate amount to the mixture.

[0110] The catalyst, titanium tetraisopropoxide (40.1 g, 0.141 mol, 1 wt. % relative to the alcohol), was added, and the mixture was heated to reflux, gradually distilling off the methanol / methyl methacrylate azeotrope. Complete conversion of the starting material was achieved after 2 h. The mixture was cooled to 60-85 °C, and the catalyst was precipitated with dilute sulfuric acid (1 wt. %) under constant stirring. After neutralization with Na2CO3 (10 wt. %), a filter aid (Tonsil) was added. Water and a portion of the excess methyl methacrylate were distilled off under vacuum and at elevated temperature. The reaction mixture was then filtered (using a pressure filtration device), and the residual solvent was removed under vacuum. The product was obtained as a clear liquid. Yield: 3582 g (88% by weight, loss on filter plate). Water content: 0.03 wt% (Karl Fischer), Ti<1 ppm (AES), MEHQ 177 ppm, GPC analysis was consistent with the expected Mw distribution based on product and starting materials.

[0111] Example 4 Synthesis of poly(ethylene glycol-co-propylene glycol) methyl ether methacrylate 4600 Poly(oxyalkylene) ether alcohol (874 g, 0.19 mol, Mw approx. 4600 g / mol) and methyl methacrylate (2377.9 g, 23.75 mol) were weighed into a reaction vessel. MEHQ (0.18 g, 200 ppm relative to the product) was added, and (dilute) air was passed through the reaction mixture. Dehydration of the mixture was carried out by azeotropic distillation of water / methyl methacrylate until the water initially present was completely distilled off. The amount of methyl methacrylate distilled off during dehydration was then replaced by adding the appropriate amount to the mixture.

[0112] LiCl (2.31 g, 0.05 mol, 0.26 wt. % relative to the alcohol) and CaO (8.18 g, 0.15 mol, 0.94 wt. % relative to the alcohol) were added, and the mixture was heated to reflux, gradually distilling off the methanol / methyl methacrylate azeotrope. Complete conversion of the starting material was achieved after 2.5 h, and then excess methyl methacrylate was partially distilled off at 200 mbar (1101 g). The mixture was cooled to 60-85 °C, and filter aid (15.7 g Tonsil) was added. The mixture was stirred for 15 min and filtered (using a pressure filtration device). Residual methyl methacrylate was removed by distillation under vacuum. The product was obtained as a clear liquid. Yield: 839.8 g (95% by weight). Water content: 0.02 wt% (Karl Fischer), OH number <0.50, acid number 0.08, MEHQ 176 ppm, GPC analysis was consistent with the expected Mw distribution based on product and starting materials (D=1.18).

[0113] Comparative example 1: PEO electrolyte Poly(ethylene oxide) (PEO) (Mw = 200,000 g / mol) (900 mg, 90 wt%) was mixed with lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (100 mg, 10 wt%) in 1 mL of acetonitrile and stirred overnight. The mixture was then poured into a Teflon mold and dried in an oven at 60 °C for 2 days to remove traces of solvent before use. Ionic conductivity was measured in a CR2032 cell by sandwiching the solid electrolyte between two pieces of stainless steel (SS).

[0114] Comparative Example 2: Photocrosslinked VISIOMER® MPEG 1005 MA electrolyte Lyophilized monomer VISIOMER® MPEG 1005 MA W (840 mg, 84 wt. %, based on the total weight of the reaction mixture) was mixed with TEGOMER® V-Si 7255 (30 mg, 3 wt. %), photoinitiator (phenyl-bis-(2,4,6-trimethylbenzoyl)-phosphinoxide, BAPO) (30 mg, 3 wt. %), and lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (100 mg, 10 wt. %), and 0.5 mL of acetonitrile was added to obtain a homogeneous solution. The mixture was stirred overnight in the dark and then poured into a Teflon mold and dried in a 60 °C oven for 2 days to remove traces of solvent before use. The material was exposed to light at room temperature for 3 h (TLC, λ = 365 nm).

[0115] Comparative Example 3: Photocrosslinked VISIOMER® MPEG 2005 MA electrolyte Lyophilized monomer VISIOMER® MPEG 2005 MA W (840 mg, 84 wt. %, based on the total weight of the reaction mixture) was mixed with TEGOMER® V-Si 7255 (30 mg, 3 wt. %), photoinitiator (phenyl-bis-(2,4,6-trimethylbenzoyl)-phosphinoxide, BAPO) (30 mg, 3 wt. %), and lithium bis(trifluoromethanesulfonyl)imide (LITFSI) (100 mg, 10 wt. %), and 0.5 mL of acetonitrile was added to obtain a homogeneous solution. The mixture was stirred overnight in the dark and then poured into a Teflon mold and dried in a 60 °C oven for 2 days to remove traces of solvent before use. The material was exposed to light at room temperature for 3 h (TLC, λ = 365 nm).

[0116] The electrochemical performances and mechanical properties of the electrolytes prepared in the examples and comparative examples were determined according to the methods described above.

[0117] The ionic conductivities of the tested electrolytes are summarized in Table 1 below. [Table 1]

[0118] As shown in FIG. 1 and Table 1 above, the electrolyte prepared in Example 2 exhibited better ionic conductivity than the electrolyte prepared in Comparative Example 3 at different temperatures from 0 to 10°C, particularly at the low temperature of 0°C, and further exhibited better ionic conductivity than those of Comparative Examples 1 and 2 at different temperatures from 0 to 30°C. Even more surprisingly, the electrolyte prepared in Example 1 exhibited much higher ionic conductivity than that of Comparative Example 2 at different temperatures from 0 to 50°C, particularly at the low temperature of 0 to 20°C, and also exhibited better ionic conductivity than those of Comparative Examples 1 and 3, at least at the low temperature of 0 to 20°C.

[0119] 1, when the temperature was decreased from 50°C to 0°C, the decrease in ionic conductivity of the electrolytes of Comparative Examples 1 to 3 was much more dramatic than that of Examples 1 and 2. Such ionic conductivity profiles of the electrolytes of the present invention with respect to temperature changes are highly advantageous, particularly when the electrolyte is used in an environment involving low temperatures or changes between low and high temperatures.

[0120] On the other hand, the mechanical performance of the electrolytes of Examples 1 and 2 was much better than that of Comparative Examples 1 to 3. The electrolytes of Examples 1 and 2 were self-supporting, highly elastic solids. The electrolyte films were very easy to handle with tools such as tweezers and remained intact when handled with tweezers. In contrast, the electrolytes of Comparative Examples 1 to 3 were solid but not elastic. When handled with tweezers, the electrolyte films easily broke and required very careful handling.

[0121] As used herein, terms such as "comprise(s)" are open terms meaning "including at least," unless otherwise specified.

[0122] All references, tests, standards, documents, publications, etc. mentioned herein are incorporated by reference. When a numerical limit or range is listed, the endpoints are included. Also, all values ​​and subranges within the numerical limit or range are specifically included as if expressly written.

[0123] The above description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiment will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiment shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, any particular embodiment within the invention may not exhibit all of the benefits of the invention broadly considered.

Claims

1. A macromonomer represented by the following general formula (I): 【Chemistry 1】 In the formula, R １ represents methyl or H; In the formula, z is the number of repeats of the ethylene glycol spacer and represents 0, 1, 2, or 3; R ２ represents methyl or a C2-C10 aliphatic or aromatic group, preferably methyl or ethyl, more preferably methyl; n represents a positive integer between 10 and 200, preferably between 10 and 100, more preferably between 40 and 80; n defines the degree of polymerization of the random copolymer having the ratio of comonomers x and y; and A macromonomer wherein y=1% to 40%, preferably 5% to 25%, more preferably 10% to 20%, even more preferably 12% to 18% and x=1-y.

2. 2. The macromonomer according to claim 1, wherein the number average molecular weight of the macromonomer is from 500 to 10,000, preferably from 500 to 5,000, for example from 600 to 4,500, more preferably from 750 to 4,000, or from 750 to 2,000, even more preferably from 800 to 1,500, for example about 1,000.

3. The macromonomer of claim 1 , wherein the macromonomer is a liquid at room temperature.

4. In formula (I), R １ represents methyl or H; z is the number of repetitions of the ethylene glycol spacer and represents 0, 1, 2, or 3; R ２ represents methyl or a C2-C5 aliphatic group, preferably methyl or ethyl, more preferably methyl; n represents a positive integer from 10 to 100; n defines the degree of polymerization of a random copolymer having the ratio of comonomers x and y; y=10% to 25%, preferably 14% to 20%, x=1-y; and the number average molecular weight of the macromonomer is 500 to 5000, preferably 750 to 2000, more preferably 800 to 1500, for example about 1000; The macromonomer according to claim 1 .

5. A) the macromonomer according to claim 1; B) siloxane monomers, particularly acrylate-functional siloxane monomers; and C) a lithium salt, and optionally D) Free Radical Initiators 1. An electrolyte precursor composition comprising:

6. the siloxane monomer is a compound of formula (II), - １ ｅ - ３ ｆ 0 １ ｇ 0 ３ ｈ (A) During the ceremony, M １ = [R １ ３ SiO １／２ ], M ３ = [R １ ２ R ３ SiO １／２ ], D １ = [R １ ２ SiO ２／２ ], D ３ = [R １ R ３ SiO ２／２ ], e=0 to 2; f=0 to 2, preferably 0, and e+f=2; g=0 to 38, preferably 10 to 26; h=0 to 20, for example 1 to 20, or 2 to 20, or 3 to 20, preferably 4 to 15; the ratio of the sum (f+h) to the sum (g+h+2) is from 0.15 to a maximum of 1, preferably from 0.2 to 0.5; the sum (g+h+2) is 4 to 40, preferably 10 to 30; R １ are the same or different aliphatic hydrocarbons having 1 to 10 carbon atoms or aromatic hydrocarbons having 6 to 12 carbon atoms, preferably methyl and / or represents a phenyl group, particularly preferably a methyl group, R ３ represents the same or different hydrocarbons having 1 to 5 identical or different ester, preferably (meth)acryloxy, functional groups, said hydrocarbons being linear, cyclic, branched and / or aromatic, preferably linear or branched, and said ester, preferably (meth)acryloxy, functional groups being selected from ethylenically unsaturated radically polymerizable esters, preferably (meth)acryloxy, functional groups, and ester groups that are not radically polymerizable.

7. The siloxane monomer is a compound of formula (II), wherein: e=2, f=0, h=4 to 15; the sum (g+h+2) is 5 to 40, preferably 10 to 30; R ３ represents the same or different hydrocarbons having 1 to 5 identical or different esters, said hydrocarbons being linear, cyclic, branched and / or aromatic, preferably linear or branched, said esters being ethylenically unsaturated, radically polymerizable esters, preferably (meth)acryloxy functional groups, and (meth)acryloxy functional groups selected from ester groups that are not radically polymerizable; and the number of radical polymerizable groups in the siloxane monomer is 3 or more; The electrolyte precursor composition of claim 5 .

8. 6. An electrolyte precursor composition according to claim 5, wherein the weight ratio of the siloxane monomer to the macromonomer is from 1:0.4 to 1:80, in particular from 1:0.8 to 1:52, preferably from 1:1.6 to 1:55, in particular from 1:1.6 to 1:52, more preferably from 1:12.8 to 1:55, even more preferably from 1:20 to 1:52, in particular from 1:12.8 to 1:

52.

9. a) providing an electrolyte precursor composition according to claim 5; and b) crosslinking the liquid electrolyte precursor composition by irradiation or heat treatment in the presence of a free radical initiator.

1. A method for preparing a solid polymer electrolyte, comprising:

10. 10. A solid polymer electrolyte prepared according to the method of claim 9 or obtained by curing the electrolyte precursor composition of claim 5.

11. 11. A solid state lithium secondary battery comprising a cathode, a solid copolymer electrolyte, and an anode, preferably a lithium metal anode, wherein the solid copolymer electrolyte is the solid copolymer electrolyte of claim 10.

12. An electrochemical device comprising the solid polymer electrolyte of claim 10.

13. A device comprising the electrochemical device of claim 12.

14. The macromonomer according to claim 3 or 4, less than 5 wt%, for example less than 4 wt%, less than 3 wt%, less than 2 wt%, preferably less than 1 wt%, for example less than 0.9 wt%, less than 0.8 wt%, less than 0.7 wt%, less than 0.6 wt%, less than 0.5 wt%, less than 0.4 wt%, less than 0.3 wt%, less than 0.2 wt%, or even less than 0.1 wt%, of a solvent based on the total weight of the macromonomer composition; The number average molecular weight of the macromonomer is 500 to 5,000, preferably 750 to 2,000, and more preferably 800 to 1,500. Macromonomer composition.

15. Use of a macromonomer according to any one of claims 1 to 4 or an electrolyte precursor composition according to any one of claims 5 to 8 in the preparation of a solid polymer electrolyte in a lithium secondary battery, in particular a lithium metal secondary battery, for improving performance such as in particular the mechanical properties, the ionic conductivity, in particular at low temperatures, and / or the cycling performance of the electrolyte.

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