METHOD FOR PRODUCING A BATTERY BASED ON AN IN-SITU-CURING ELECTROLYTE AND BATTERY

Abstract

An in-situ curing electrolyte precursor liquid comprising a first component, a second component, a third component, a catalyst, an initiator, and an electrolyte liquid; wherein the first component comprises at least one first monomer, the first monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 2; wherein the second component comprises at least one second monomer, the second monomer capable of copolymerizing with the first monomer; wherein the third component comprises at least one third monomer, the third monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 1.

Description

[0001] The present invention relates to the field of materials, in particular to a method for producing a battery based on an in-situ curing electrolyte and a battery.

[0002] Lithium-ion batteries are widely used in electronic products, electric vehicles, and large-scale energy storage, among other fields, due to their high energy density and good cycling performance. With the expansion of application areas, safety issues with lithium-ion batteries are gradually being revealed. The internal space of lithium-ion batteries contains a large amount of flammable electrolyte, which can easily lead to safety problems. Electrolyte hardening is considered an effective way to solve this problem, but due to complex processing and large interfacial impedance, solid electrolytes cannot be quickly mass-produced.

[0003] To solve the problem of lack of mass production, researchers have proposed an in-situ polyelectrolyte that is compatible with current production equipment while reducing interfacial impedance. For example, in Chinese patent application CN102903953A, a gel polymer and two acrylate monomers are dissolved in an electrolyte and injected into a battery. After curing, a cured electrolyte is formed. The monomers and polymer form a pig-cage-like structure to enclose the electrolyte, prevent its volatilization, and improve battery safety.In Chinese patent application CN108987791A, three monomers, namely a multifunctional acrylate, a monofunctional acrylate, and an amine acrylate, are added to an electrolyte and polymerized in situ, whereby a gel electrolyte with excellent electrical properties is obtained by regulating the ratio between the monomers.

[0004] Existing in-situ polymerization processes mostly utilize free radicals to initiate polymerization of acrylate monomers. The mechanism of free radical-initiated monomer polymerization is chain polymerization. The polymerization process releases a large amount of heat, the reaction activation energy is low, and the free radicals are prone to problems such as solvent transfer and double radical termination during the polymerization process. This leads to polydispersity in the molecular weight of the polymerization product and uneven polymer distribution, which can cause minor problems such as polymer oxidation and lithium precipitation in the negative electrode, thus affecting battery performance.

[0005] In view of the above-mentioned problems, prepolymerization is often used in the prior art to make improvements.

[0006] From CN114069036A, a manufacturing process for a gel electrolyte is known, in which an acrylate monomer is mixed with an initiator, a crosslinker, and carbon oxide nanoparticles to obtain a mixture which is first subjected to a first polymerization (“prepolymerization”) and to which a crosslinking agent is subsequently added, the resulting mixture being injected into the battery and then subjected to a second polymerization (“gel reaction”) under vacuum to obtain a gel electrolyte and a lithium-ion battery, thereby solving the problem of uneven polymerization caused by non-uniform chemical environments in battery cells.

[0007] CN108847504A proposes that an acrylate monomer, a hydroxyl(carboxyl)-containing acrylate monomer, and an initiator are stirred, then subjected to prepolymerization, and cooled after completion of this prepolymerization to obtain a prepolymerized electrolyte with a viscosity of 100 to 2000 cps. A crosslinking agent and a catalyst are then added to the prepolymerized electrolyte. The resulting mixture is then injected into a battery cell and cured at high temperature to obtain a solid battery cell. This solves the problem of deterioration in electrical performance caused by the low conversion rate of conventional in-situ curing monomers.

[0008] Although the above-mentioned solutions, which increase the polymerization degree by pre-polymerizing monomers outside a battery cell and then injecting liquid, are adopted, a commercial battery cell is difficult to infiltrate with an electrolyte liquid due to its thick electrodes and micrometer-sized pores. Furthermore, to improve the fit of the wound core, a square-wound battery cell also uses a thermal compounding process, which further increases the infiltration difficulty. Commercial batteries generally require an electrolyte viscosity of less than 10 mPa·S to meet the requirements for complete infiltration. However, using a pre-polymerization solution generally increases the viscosity of a precursor liquid, resulting in poor infiltration and unable to meet production requirements.

[0009] Technical problems to be solved by the present invention include: 1. Problem of uneven polymerization: Currently, radical polymerization is mainly used for in-situ curing, in which the polymerization process releases a large amount of heat, the reaction activation energy is low, and the free radicals are prone to problems such as transfer to solvent and termination of double radicals during their polymerization process, resulting in low polymerization degree and easy oxidation and decomposition by the positive electrode with high nickel content. 2. The problem of uneven infiltration: The currently used method, which involves pre-polymerization followed by liquid injection, can improve uneven polymerization, but significantly increases the viscosity of the precursor liquid. This leads to uneven battery infiltration or excessively long infiltration times, which is not conducive to mass production and manufacturing.

[0010] In embodiments of the present invention, a method for producing a battery based on an in-situ curing electrolyte is proposed, the method comprising: 1) Adding a first component, a second component, and a third component to an electrolyte liquid, which is then subjected to uniform stirring, followed by adding a catalyst and an initiator, and further stirring to obtain an in-situ curing precursor liquid; wherein the first component comprises at least a first monomer, the first monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 2; wherein the second component comprises at least a second monomer, the second monomer capable of copolymerizing with the first monomer;wherein the third component comprises at least a third monomer, the third monomer containing both a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 1; 2) Injecting the in-situ curing precursor liquid obtained in step 1) into the interior of a battery and allowing it to stand so that a pole piece and a separator are completely infiltrated; 3) Performing a first curing on a battery cell infiltrated in step 2) at a first temperature and then performing a second curing on the battery cell at a second temperature to obtain the battery based on an in-situ curing electrolyte.

[0011] According to one embodiment of the present invention, for example, it is provided that the functional group for chain polymerization is a carbon-carbon double bond, wherein the functional group for stepwise polymerization is selected from at least one of hydroxyl group, amine group and amide group; wherein the second monomer preferably comprises a diisocyanate monomer; wherein the second monomer preferably comprises a diisocyanate monomer and a diol; wherein the in-situ curing precursor liquid preferably has a viscosity of not more than 10 mPa·S at a temperature of 25°C; wherein the in-situ curing precursor liquid more preferably has a viscosity of not more than 8 mPa·S at a temperature of 25°C; wherein the in-situ curing precursor liquid more preferably has a viscosity of not more than 6 mPa·S at a temperature of 25°C.

[0012] For example, according to one embodiment of the present invention, it is provided that the first monomer having a functionality of stepwise polymerization of 2 can be selected from hydroxyl-containing acrylates or hydroxyl-containing acrylamides.

[0013] This includes, in particular, at least one of N-hydroxymethylacrylamide, N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)methacrylamide, dihydroxypropyl acrylate, and 2,3-dihydroxypropyl methacrylate. Preferably, it is a hydroxyl-containing acrylate.

[0014] According to one embodiment of the present invention, for example, it is provided that the second monomer is at least one of the following: diisocyanates, and compositions of a diisocyanate and a diol.

[0015] The diisocyanates include in particular: toluene diisocyanate, hexamethyl diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, polymerized diphenylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, biuret triisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylene diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 1,4-cyclohexyl diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyltolyldimethylene diisocyanate, methylcyclohexyl diisocyanate, decamethylene diisocyanate, 1,12-dodecane diisocyanate, 2,2,4-trimethylcyclohexyl diisocyanate, triphenylmethane triisocyanate, 4,4',4"-triphenylphosphorothioate triisocyanate, cyclohexane dimethylene diisocyanate, 4,4'-Dicyclohexylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, 4,4'-diphenyl diisocyanate, norbornene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 2-methylpentane diisocyanate, 4,4'-Diphenyl ether diisocyanate, 4-methyldiphenylmethane-3,4-diisocyanate, 2,4'-diphenyl sulfide diisocyanate, diethylbenzene diisocyanate, 4,4'-diphenylethane diisocyanate. These diisocyanates are preferably aromatic diisocyanates.

[0016] The diols are selected from diols containing ether segments and include, in particular, diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol. The diols are preferably diethylene glycol, triethylene glycol, or tetraethylene glycol.

[0017] Preferably, the second component is selected from compositions of an aromatic diisocyanate and a low-molecular-weight diol. A chain segment formed by the diisocyanate alone is relatively hard. The addition of the diol contributes to improving molecular flexibility, fluid absorption and retention capacity, and ion migration capacity.

[0018] According to one embodiment of the present invention, for example, it is provided that the third monomer is selected from at least one of acrylamides, acrylates having a hydroxyl group, and acrylates having an isocyanate, including in particular acrylamide, N-methacrylamide, N-ethylacrylamide, N-isopropylacrylamide, 2-hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 2-(acryloyloxy)ethyl isocyanate, and isocyanatoethyl methacrylate, wherein the third monomer is preferably acrylamide.

[0019] According to one embodiment of the present invention, for example, step 1) comprises: the first component, the second component, and the third component are added to the electrolyte liquid, which are then subjected to uniform stirring; subsequently, the catalyst, the initiator, and a polymerization inhibitor are added; then, further stirring is carried out to obtain the in-situ curing precursor liquid; wherein the polymerization inhibitor is preferably selected from at least one of 1,4-benzoquinone, 2,2-biphenyl-1-picrylhydrazyl, 2-amino-5-nitrobenzophenone, 3-nitroacetophenone, 4-methoxyphenol, N,N-diethylhydroxylamine, tannic acid, phenothiazine, methyl decanoate, galvinoxyl radical; wherein preferably the molar ratio of the first component, the second component and the third component is 1:(2 to 3):(0.3 to 0.8), preferably 1:(2.2 to 2.8):(0.4 to 0.6).

[0020] According to one embodiment of the present invention, for example, it is provided that the initiator is selected from at least one of azobisisobutyronitrile, azobisisoheptonitrile, dimethyl 2,2'-azobis(2-methylpropionate), 1-((cyano-1-methylethyl)azo)carboxamide, azodicarbonamide, dicumyl peroxide, di-tert-butyl peroxide, cumyl hydroperoxide, and preferably 1-((cyano-1-methylethyl)azo)carboxamide, azodicarbonamide, dicumyl peroxide or di-tert-butyl peroxide; wherein preferably the mass of the initiator constitutes 0.5 to 1.5% of the total mass of the first component and the third component; wherein preferably the catalyst is selected from at least one of the following: trialkylphosphine, tertiary amine, quaternary ammonium salt, compounds of the elements of the nitrogen family, organosilicon-phosphorus heteroatom compounds, organometallic compounds and alkaline carboxylates, etc., such as triethylphosphine, pyridine, dimethylphenylphosphine, tris(dimethylaminopropyl)hexahydrotriazine, 2,4,6-tris(dimethylaminomethyl)phenol, trimethyl-N-2-hydroxypropylhexanoic acid, tetramethylammonium octanoate, N-hydroxyalkyl quaternary ammonium base, potassium acetate, triphenylphosphine, tri-n-butylphosphine, lithium acetate, butyllithium, cesium fluoride, tributyltin oxide, tetrabutyl titanate, tetrabutyl zirconate, tin alkoxide, dialkyltin oxide, N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, Triethylenediamine, triethylamine, N,N,N',N'-tetramethylalkylenediamine, N,N-dimethylbenzylamine, N,N-dimethylbutylamine, N,N-dimethylhexadecylamine, N-ethylmorpholine, N-methylmorpholine, N,N-Diethylpiperazine, N,N-Diethyl-2-methylpiperazine, N,N'-Bis(α-hydroxypropyl)-2-methylpiperazine, triethanolamine, N,N-dimethylethanolamine, N,N-lutidine, (dimethylaminoethyl)ether, N-methylethylenediamine, dimethylformamide, triethylenethanediamine, diethyleneglycolamine and triethylenediamine, hexamethyldisilazane, Lithium bistrifluoromethylsulfonimide, lithium bisfluorosulfonimide, potassium carboxylate, tin octoate;, wherein the mass of the catalyst preferably amounts to 0.2 to 0.8%, preferably 0.5%, of the mass of the second component; wherein preferably the total mass of the first component, the second component and the third component amounts to 2 / 98 to 30 / 70, preferably 5 / 95 to 20 / 80, of the mass of the electrolyte.

[0021] According to one embodiment of the present invention, for example, it is provided that the second temperature is higher than the first temperature; wherein the second temperature is preferably at least 10°C higher than the first temperature, more preferably the second temperature is at least 20°C higher than the first temperature, further preferably the second temperature is at least 30°C higher than the first temperature, most preferably the second temperature is at least 40°C higher than the first temperature; wherein the first temperature is 40 to 80 °C, preferably 40 to 60 °C, wherein the first temperature within this temperature range can ensure a first curing reaction and exceeding this temperature range results in the initiator of a second reaction being decomposed in advance and initiating crosslinking; wherein the second temperature is 50 to 100°C, preferably 60 to 90°C. The second temperature within this temperature range can ensure a second curing reaction; exceeding this temperature range results in the decomposition of the salt in the electrolyte liquid and thus the formation of byproducts, which adversely affects the electrical performance.

[0022] The embodiments of the present invention also provide a battery manufactured according to the above-described method for manufacturing a battery based on an in-situ curing electrolyte.

[0023] Embodiments of the present invention further provide an in-situ-curing electrolyte precursor fluid, wherein the in-situ-curing electrolyte precursor fluid comprises a first component, a second component, a third component, a catalyst, an initiator, and an electrolyte fluid; wherein the first component comprises at least a first monomer, wherein the first monomer contains a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 2; wherein the second component comprises at least a second monomer, wherein the second monomer is capable of copolymerizing with the first monomer;wherein the third component comprises at least a third monomer, the third monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 1.;

[0024] According to one embodiment of the present invention, for example, it is provided that the first component consists of a first monomer and the second component consists of a second monomer; wherein preferably the functional group for chain polymerization is a carbon-carbon double bond, and the functional group for stepwise polymerization is selected from at least one of hydroxyl group, amine group and amide group; wherein the second monomer preferably comprises a diisocyanate monomer; wherein the second monomer preferably comprises a diisocyanate monomer and a diol; wherein the in-situ curing electrolyte precursor liquid has a viscosity of not more than 10 mPa·S at a temperature of 25°C; wherein the in-situ curing precursor liquid more preferably has a viscosity of not more than 8 mPa·S at a temperature of 25°C; wherein the in-situ curing precursor liquid more preferably has a viscosity of not more than 6 mPa·S at a temperature of 25°C; wherein preferably the molar ratio of the first component, the second component and the third component is 1:(2 to 3):(0.3 to 0.8), preferably 1:(2.2 to 2.8):(0.4 to 0.6).

[0025] The functionality referred to herein refers to the number of functional groups in a molecule that can participate in a specific polymerization reaction during a condensation reaction.

[0026] The stepwise polymerization referred to herein refers to a stepwise polymerization reaction without an active center in which the functional monomer groups react with each other and thus gradually grow, including the reaction of isocyanate and hydroxyl group, the reaction of isocyanate and amino group, and the reaction of isocyanate and amide group.

[0027] Chain polymerization, as referred to herein, refers to a reaction in which active centers (free radicals or ions) are formed during a polymerization reaction, allowing many monomers to be polymerized together in a short time to form high-molecular-weight macromolecules. Chain polymerization, as referred to herein, refers to a polymerization reaction of groups containing unsaturated double bonds in the presence of free-radical initiators.

[0028] The present invention provides an in-situ polymerized electrolyte wherein monomers for two types of polymerization mechanisms, namely stepwise polymerization and chain polymerization, are introduced, wherein the monomers used for stepwise polymerization are used for the growth of a polymer molecular chain, wherein the monomers used for chain polymerization are used for later crosslinking, whereby a crosslinked polymer electrolyte with a long main chain length is obtained by utilizing the characteristics of the gradual polymerization, namely low heat release, mild reaction, and high conversion rate in the early stage of the reaction, thereby improving the oxidation resistance of the electrolyte.In the later stages of polymerization, the low activation energy of radical polymerization is utilized to reduce the reaction energy barrier and obtain highly cross-linked polymers. The raw materials used, i.e., the polymerized monomers, are all low-molecular-weight monomers. While ensuring that the viscosity of the electrolyte during injection is less than 6 mPa·S, they achieve the effect of stepwise polymerization. This improves the penetration into the microporous structure of the battery and the homogeneity of the macroscopic distribution of the polymer within the battery. It also solves the problems of uneven polymerization and uneven infiltration during the in-situ curing process, significantly improving lithium precipitation, cycle life, and battery load capacity.In addition, this solution uses a one-pot process, which simplifies the production process and enables extremely easy mass production.

[0029] The invention described above is explained in more detail below using an exemplary embodiment. Fig. 1 shows a representation of a pole piece of a disassembled battery according to embodiment 1; Fig. 2 shows a diagram of a pole piece of a disassembled battery according to Comparative Example 3; Fig. 3 shows a diagram of a pole piece of a disassembled battery according to Comparative Example 4; Fig. 4 shows the test results of the electrochemical window of Embodiment 1, Comparative Example 3 and Comparative Example 4; Fig. 5 shows the battery cycle test results of Embodiment 1, Comparative Example 3 and Comparative Example 4; Fig. 6 shows a representation of a pole piece of a large commercial battery cell disassembled using the solution according to Embodiment 1; Fig. 7 shows a representation of a pole piece of a large commercial battery cell disassembled using the solution according to Comparative Example; Fig. Figure 8 shows a representation of a pole piece of a large commercial battery cell disassembled using the solution according to Comparative Example 4.

[0030] To further clarify the object, technical solutions, and advantages of the present invention, the present invention will be described in more detail below in conjunction with specific embodiments and with reference to the accompanying drawings. However, those skilled in the art will appreciate that the present invention is not limited to the accompanying drawings and the following embodiments.

[0031] The same implementation means used in the following embodiments and comparative examples include: pouch battery NCM811 / graphite, commercially available electrolyte liquid, nominal capacity of 10.5 Ah, charge and discharge voltage range from 2.75 V to 4.25 V.

[0032] Test method: 1. A rotational viscometer is used to test the viscosity of the electrolyte fluid, with the test temperature being 25 °C. 2. A stainless steel / Li button battery is assembled to perform an electrochemical window test on the electrolyte, with the test voltage range being OCV-5V and the scanning speed being 1mV / s. 3. A device from Wuhan Land Electronics Co., Ltd. is used to conduct a 0.5C charge and discharge test on a pouch cell, with the voltage range being between 2.75 V and 4.25 V, so that information about the capacity utilization and cycle of the pouch battery can be obtained. 4. After disassembling the battery, the homogeneity of the surface appearance of the pole piece is visually compared. 5. An AC impedance meter is used to test the internal resistance of the battery. Example 1 1) Preparation of an in-situ curing precursor fluid: Dihydroxypropyl acrylate, toluene diisocyanate, tetraethylene glycol, and acrylamide are added in a molar ratio of 1:2:0.5:0.5 with a total mass of 10 g to a commercially available electrolyte fluid with a mass of 90 g (EC / EMC / DMC=1 / 1 / 1 v / v / v, 5% wt / VC, 1M LiPF6) and then stirred for 1 hour at room temperature. After uniform stirring, 0.028 g of the catalyst "tin octoate" and 0.043 g of the initiator "1-cyano-1-methylethylazocarboxamide" are added. After further stirring for 30 minutes, the in-situ curing precursor fluid is obtained. The precursor fluid is subjected to a viscosity test at a temperature of 25 °C, stored for 24 hours at a temperature of 40 °C, and then subjected to another viscosity test. 2) 20 g of the in-situ curing precursor liquid obtained in step 1) are injected into the interior of the battery and left to stand for 24 hours at a temperature of 25 °C to allow the electrolyte liquid to completely infiltrate the pole pieces and separators. 3) The battery cell infiltrated in step 2) is left to stand for 24 hours at a temperature of 40°C and subjected to a first cure. After the first cure, the battery cell is left to stand for 5 hours at a temperature of 80°C and subjected to a second cure. After the second cure, a portion of the battery cell is disassembled. The homogeneity of the pole piece is then observed. 4) The battery cell, which has been hardened but not disassembled in step 3), is shaped and divided into different capacities. After the capacity division is complete, the internal resistance of the battery is tested with an AC impedance meter. A charge and discharge cycle test is then performed. 5) When testing the electrochemical window, the precursor fluid from step 1) is used to assemble the button battery. Then, curing is performed according to steps 2) and 3). Afterward, an electrochemical window test is performed. Example 2

[0033] Compared to Example 1, the temperature during the first curing step in step 2) is set to 50 °C, while the temperature during the second curing step in step 3) is set to 60 °C. The remaining processes are the same as in Example 1. Example 3

[0034] Compared to Example 1, the temperature during the first curing step in step 2) is set to 60 °C, while the temperature during the second curing step in step 3) is set to 90 °C. The remaining processes are the same as in Example 1. Example 4

[0035] Compared to Example 1, the temperature during the first curing step in step 3) is set to 70 °C, while the temperature during the second curing step in step 3) is set to 100 °C. The remaining processes are the same as in Example 1. Example 5

[0036] Compared to Example 1, the temperature during the first curing in step 3) is set to 80 °C, while the temperature during the second curing in step 3) is set to 110 °C. The remaining processes are the same as in Example 1. Example 6

[0037] The dihydroxypropyl acrylate in the formula of the precursor liquid of step 1) in Example 1 is replaced with N-hydroxymethylacrylamide. The remaining procedures are the same as in Example 1. Example 7

[0038] The acrylamide in the formula of the precursor liquid of step 1) in Example 1 is replaced with hydroxypropyl acrylate. The remaining procedures are the same as in Example 1. Example 8

[0039] A polymerization inhibitor "4-methoxyphenol," which constitutes 10% of the initiator mass, is added to the precursor liquid formula in Example 1. The remaining procedures are the same as in Example 1. Example 9

[0040] A polymerization inhibitor "phenothiazine," which constitutes 10% of the initiator mass, is added to the precursor liquid formula in Example 1. The remaining procedures are the same as in Example 1. Example 10

[0041] A polymerization inhibitor "1,4-benzoquinone," which constitutes 10% of the initiator mass, is added to the precursor liquid formula in Example 1. The remaining procedures are the same as in Example 1. Example 11

[0042] Toluene diisocyanate and tetraethylene glycol in the formula of the precursor liquid in Example 1 are replaced by isophorone diisocyanate and tetraethylene glycol. The remaining processes are the same as in Example 1. Example 12

[0043] Toluene diisocyanate and tetraethylene glycol in the formula of the precursor liquid in Example 1 are replaced by hexamethylene diisocyanate and tetraethylene glycol. The remaining processes are the same as in Example 1. Example 13

[0044] Tetraethylene glycol in the formula of the precursor fluid in Example 1 is replaced by polyethylene glycol with a molecular weight of 2000. Example 14

[0045] Compared to Example 1), the mass ratio of the monomer to the commercially available electrolyte liquid is changed from 1 / 9 to 2 / 8. The remaining processes are the same as in Example 1. Example 15

[0046] Compared to Example 1), the mass ratio of the monomer to the commercially available electrolyte liquid is changed from 1 / 9 to 5 / 95. The remaining processes are the same as in Example 1. Example 16

[0047] Compared to Example 1), the mass ratio of the monomer to the commercially available electrolyte liquid is changed from 1 / 9 to 2 / 98. The remaining processes are the same as in Example 1. Example 17

[0048] Compared to Example 1), the mass ratio of the monomer to the commercially available electrolyte liquid is changed from 1 / 9 to 3 / 7. The remaining processes are the same as in Example 1. Comparison example 1

[0049] A commercially available electrolyte fluid (EC / EMC / DMC=1 / 1 / 1v / v / v, 5% wtVC, 1 M LiPF6)) is injected, which is then infiltrated for 24 hours at a temperature of 25 °C and then subjected to tests such as formation and capacity division. Comparison example 2

[0050] Comparative Example 2 differs from Working Example 1 in that the initiator in the precursor liquid in step 1 is replaced with azobisisoheptonitrile, and the catalyst tin octoate is not added. The remaining processes are the same as in Working Example 1. In Working Example 1, a stepwise polymerization is performed first, followed by a chain polymerization. In Comparative Example 2, a low-temperature initiator and no catalyst are used. This results in the stepwise polymerization process being delayed and the chain polymerization occurring prematurely. Thus, the chain polymerization begins before the stepwise polymerization is completed. Comparison example 3 1) Preparation of an in-situ curing precursor fluid: 2.94 g of dihydroxypropyl acrylate and 1.43 g of acrylamide are added to a commercially available electrolyte fluid with a mass of 90 g and then stirred at room temperature for 1 hour. Then, 0.043 g of azobisisobutyronitrile is added, and stirring is continued for another 30 minutes. The resulting mixture is then stirred at 80 °C for 10 hours and subsequently subjected to a viscosity test. 2) After completion, 3.5 g of toluene diisocyanate, 2.13 g of tetraethylene glycol and 0.028 g of stannous octoate are added and then stirred for 5 hours to form an in-situ curing precursor liquid. 3) The in-situ curing precursor fluid obtained in step 2) is injected into the battery and subjected to infiltration for 24 hours at a temperature of 25 °C, followed by a reaction for 5 hours at a temperature of 70 °C. After curing is complete, a portion of the battery cell is disassembled to observe the homogeneity of the pole piece. 4) The battery cell, cured but not disassembled in step 3), is shaped and divided into different capacities. It is then subjected to a charge and discharge cycle test. For electrochemical window testing, the precursor fluid from step 1 is used to assemble the button battery. Curing is then performed according to steps 2 and 3. Afterward, an electrochemical window test is performed.

[0051] The biggest difference between Comparative Example 3 and Working Example 1 is that in step 1) of Comparative Example 3, high-temperature prepolymerization is carried out, that is, in Comparative Example 3, prepolymerization is carried out first and then liquid is injected. Comparison example 4 1) Preparation of an in-situ curing precursor fluid: 8 g of methyl methacrylate is added to a 90 g commercially available electrolyte fluid, followed by stirring at room temperature for 1 hour. Then, 0.1 g of azobisisobutyronitrile is added, and stirring is continued for 30 minutes. The resulting mixture is then stirred at 80°C for 5 hours. Then, 2 g of ethylene glycol dimethacrylate is added as a crosslinking agent, followed by further stirring for 1 hour. A viscosity test is then conducted. 2) 20 g of the in-situ curing precursor liquid obtained in step 1) are injected into the interior of the battery and left to stand for 24 hours at a temperature of 25 °C to allow the electrolyte liquid to completely infiltrate the pole pieces and separators. 3) The battery cell infiltrated in step 2) is left to stand for 5 hours at a temperature of 80 °C and subjected to a second curing. After curing is complete, a portion of the battery cell is disassembled to observe the homogeneity of the pole piece. 4) The battery cell, cured but not disassembled in step 3), is shaped and divided into different capacities. It is then subjected to a charge and discharge cycle test. For electrochemical window testing, the precursor fluid from step 1 is used to assemble the button battery. Curing is then performed according to steps 2 and 3. Afterward, an electrochemical window test is performed.

[0052] The biggest difference between Comparative Example 4 and Working Example 1 is that Comparative Example 4 uses a conventional method of first pre-polymerizing free radicals and then injecting them into the battery for two-step crosslinking. Comparison example 5

[0053] The dihydroxypropyl acrylate in Example 1 is replaced with 2-acrylic acid 2-hydroxy-1,3-propylene-dioxy-2-hydroxy-3,1-propylene ester. The remaining procedures are the same as in Example 1. Comparison example 6

[0054] The dihydroxypropyl acrylate in Example 1 is replaced with N-trihydroxymethylmethacrylamide. The remaining procedures are the same as in Example 1.

[0055] The results of the above-described embodiments and comparative examples are summarized in the following Table 1. Discussion of the results: (1) From the comparison of Embodiment 1, Comparative Example 3, and Comparative Example 4, it can be seen that Embodiment 1 uses the technical solution of the present invention, i.e., no prepolymerization is carried out, while Comparative Examples 3 and 4 prepolymerize outside a battery cell for 5 hours at a temperature of 80°C; that the viscosity of the in-situ curing precursor liquid measured at 25°C in Embodiment 1 is 5.5 mPa·S, while the viscosity of the precursor liquid measured under the same conditions in Comparative Example 3 and Comparative Example 4 is 235 mPa·S and 358 mPa, respectively. It can be seen that the interface state and the internal resistance of the battery in Embodiment 1 are significantly lower after infiltration.Due to the high viscosity of the precursor fluids in Comparative Examples 3 and 4, the pole pieces and separators cannot be fully infiltrated after injection into the battery cell. It is observed that the infiltration state of Comparative Examples 3 and 4 contains bubbles and is heterogeneous, which further affects Comparative Examples 3 and 4, resulting in a reduction in the electrochemical window, an increase in the internal resistance of the battery, and a decrease in cycle performance. (2) From the comparison of the results of Embodiment 1, Comparative Example 2, and Comparative Example 4, it can be seen that in Comparative Example 2, the formula is changed to perform free radical polymerization first and then polycondensation, and the electrochemical window of Comparative Example 2 is not as good as that of Embodiment 1, indicating that a higher degree of monomer reaction is realized in the solution used in Embodiment 1 of the present invention; similarly, Comparative Example 4 uses only free radical reaction, performing prepolymerization first and then crosslinking (the crosslinking agent is the second monomer), and due to the viscosity and conversion rate, the performance of Comparative Example 4 is not as good as that of Embodiment 1. (3) Comparing the results of Working Examples 1 to 5, it can be seen that as the first temperature increases, the internal resistance of the battery increases, the electrochemical window decreases, and the cycle performance also decreases. This is because if the first temperature is too high, the crosslinking reaction that should have occurred in the second step occurs prematurely, resulting in the viscosity of the electrolyte increasing too rapidly, the conversion rate of monomers decreasing, and the concomitant reduction of the electrolyte's resistance to high-pressure oxidation, which also affects the battery performance. If the second temperature is too high, the electrolyte fluid deteriorates, resulting in a decrease in the electrical performance. (4) Comparing Embodiment 1 with Embodiment 6, it can be seen that the internal resistance of the battery of Embodiment 6 is larger than that of Embodiment 1. In Embodiment 6, the dihydroxypropyl acrylate in the formula of the precursor liquid of step 1) in Embodiment 1 is replaced with N-hydroxymethylacrylamide, and the other procedures are the same as in Embodiment 1. When amides are selected as the first monomer (Embodiment 6), the internal resistance of the battery is relatively large. This may be because hydrogen bonds are present in the polymer after a reaction and the cohesion is too high, resulting in poor liquid absorption capacity. The first monomer is preferably hydroxyl-containing acrylates. (5) From the comparison of Embodiment 1 with Embodiment 7, it can be seen that the electrochemical window of Embodiment 7 is smaller than that of Embodiment 1. In Embodiment 7, the acrylamide in the formula of the precursor liquid of step 1) in Embodiment 1 is replaced with hydroxypropyl acrylate, and the other operations are the same as in Embodiment 1. From this, it can be concluded that when amides are selected as the third monomer (Embodiment 1), the electrochemical window is improved, and the oxidation resistance of the electrolyte can be improved by the appropriate introduction of amide monomers. (6) In Working Examples 8 to 10, a polymerization inhibitor is added based on Working Example 1. From Table 2, it can be seen that in Working Examples 8 to 10, due to the addition of the polymerization inhibitor, the viscosity of the precursor liquid is lower after 24 hours of storage at 40°C. This is because, without the addition of the polymerization inhibitor, the monomers to be used in the second step of the reaction are slightly polymerized during the first step of the reaction at 40°C, which leads to premature crosslinking and is not favorable for the infiltration of the electrolyte liquid into the battery cell. (7) In Comparative Example 5, the first monomer in Working Example 1 is replaced with 2-acrylic acid (2-hydroxy-1,3-methylene)bis[oxy(2-hydroxy-3,1-methylene)] ester, whose functionality is 3. In Comparative Example 6, the first monomer in Working Example 1 is replaced with N-[tris(hydroxymethyl)methyl]acrylamide, whose functionality is 3. As can be seen from Table 2, the electrochemical windows of Comparative Examples 5 and 6 are significantly lower than those of Working Example 1. This is because when the functionality of the first monomer is comparatively high, premature crosslinking easily occurs, resulting in a decrease in the molecular weight of the polymer main chain, causing residue formation, and ultimately leading to deterioration in battery performance. (8) From the comparison of the results of Example 1, Example 11, and Example 12, it is clear that an aromatic isocyanate monomer is preferable as the second monomer over aliphatic isocyanate or alicyclic isocyanate. This is because the aromatic monomer in Example 1 has high reactivity, promotes the reaction at low temperature in the first stage, has a higher conversion rate, and is less likely to remain. Thus, the battery ultimately performs better. From Comparative Example 1 and Comparative Example 13, it is clear that by selecting polyethylene glycol having a higher molecular weight, the viscosity of the electrolyte liquid is increased to some extent, and the electric performance after the subsequent injection decreases slightly. (9) From the comparison of the results of Embodiments 1, 14, 15, 16, and 17, it is clear that, considering various battery performance indicators comprehensively, it is a better choice to set the monomer mass to 5 to 20% of the sum of the monomer mass and the electrolyte mass in Embodiment 1. In Embodiment 14, the monomer mass is increased to 20% of the sum of the monomer mass and the electrolyte mass; although the capacity and cycle performance decrease to some extent, and the internal resistance of the battery increases to some extent, the electrochemical window is improved to some extent compared to Embodiment 1.This is because polymers exhibit better oxidation resistance than low-molecular-weight solvents in the electrolyte liquid. As the polymer content increases, low-molecular-weight solvents have less contact with electrodes, improving the overall oxidation resistance of the electrolyte. This can also be seen in the pure electrolyte liquid of Comparative Example 1; although the electrolyte liquid has no problem with infiltration uniformity, the electrolyte liquid exhibits poorer oxidation resistance and lower cycling stability than solid electrolyte. When the monomer mass further increases to 30% of the sum of the monomer mass and the electrolyte mass (Working Example 17), the viscosity of the injected liquid increases, which has a certain impact on battery infiltration and leads to a reduction in battery performance. In Embodiment 15 and Embodiment 16, the above-mentioned content is reduced to 5% and 2%, respectively. The electrochemical window, internal resistance of the battery, and capacity are not significantly changed, but the cycle performance decreases. In particular, the cycle performance of Embodiment 16 decreases significantly because, after the polymer content decreases to a certain level, the electrolyte components dominate, and the oxidation property is mainly determined by the electrolyte solvent molecules themselves. Although the basic performance is not significantly different in initial tests, low-molecular-weight solvents undergo continuous side reactions during long cycles, resulting in poor cycle performance. (10) From the Fig. 1 to 3 and Fig. 6 to 8 it can be seen that in comparison with the pole pieces obtained by the conventional method in which pre-polymerization is carried out first and then liquid injection and polymerization are carried out ( Fig. 2 and Fig. 3), the pole pieces obtained by the stepwise polymerization of the present invention ( Fig. 1) have a pole piece surface that is more evenly covered with polymer after disassembly. This effect is more evident in large commercial batteries. As shown in Fig. 6 (the solution of the present invention), the degree of coverage of the polymers on the pole piece surface is significantly higher. In Fig. 7 there is obviously a large uncovered area. In Fig. 8, there are circular, uncovered areas, indicating that a large number of bubbles have not been discharged. This is because using the process that initially involves pre-polymerization, the viscosity of the electrolyte liquid is significantly increased, resulting in poor fluidity and wettability.

[0056] As from Fig. As can be seen from Figure 4, in the linear voltammetry scan test with the battery blocked, the current of Example 1 is significantly lower, indicating that the electrolyte itself is less oxidized and decomposed. This is because Comparative Examples 3 and 4 use radical polymerization for the early growth of molecular chains. Radical polymerization itself is difficult to control and prone to various problems such as transfer and termination, resulting in a low degree of polymerization of the main chain and reduced oxidation resistance. In contrast, the present invention uses stepwise polymerization, which achieves better effects.

[0057] Out of Fig.5 shows that in Example 1, the battery performance gradually decreases with increasing cycle number, and only when the cycle number exceeds 400 does the battery performance deteriorate rapidly. For Comparative Example 3, the number of cycles at which the battery performance rapidly deteriorates is 100. For Comparative Example 4, the number of cycles at which the battery performance rapidly deteriorates is 200. This is because uneven infiltration or polymerization impairs ion transfer, and a long cycle is prone to lithium precipitation, leading to performance deterioration.

[0058] The advantageous effects of the present invention can be summarized as follows: 1. In the present invention, monomers are used for two types of polymerization mechanisms, distinguishing two steps, namely main chain growth and crosslinking, avoiding abnormal polymerizations such as solvent transfer, double radical termination, crosslinking to form a ring, explosive polymerization, etc. in the early radical polymerization process of the conventional in situ curing, and the formed electrolyte has a higher electrochemical window and is more suitable for long cycles. 2. The viscosity of the precursor liquid during injection according to the present invention is less than 10 mPa·s, which promotes the infiltration of the battery cell by the electrolyte liquid, the surface of the disassembled pole piece is more uniform and bubble-free, and the internal resistance of the battery cell is lower. 3. The present invention uses a one-pot process, which has a positive effect on the expansion of production. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 102903953A

[0003] CN 108987791A

[0003] CN 114069036A

[0006] CN 108847504A

[0007]

Claims

[1] Process for producing a battery based on an in-situ curing electrolyte, characterized by that the procedure includes: 1) Adding a first component, a second component, and a third component to an electrolyte liquid, which is then subjected to uniform stirring, followed by adding a catalyst and an initiator, and further stirring to obtain an in-situ curing precursor liquid; wherein the first component comprises at least a first monomer, the first monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 2; wherein the second component comprises at least a second monomer, the second monomer capable of copolymerizing with the first monomer;wherein the third component comprises at least a third monomer, the third monomer containing both a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 1; 2) Injecting the in-situ curing precursor liquid obtained in step 1) into the interior of a battery and allowing it to stand so that a pole piece and a separator are completely infiltrated; 3) Performing a first curing on a battery cell infiltrated in step 2) at a first temperature and then performing a second curing on the battery cell at a second temperature to obtain the battery based on an in-situ curing electrolyte. [2] A process for producing a battery based on an in-situ curing electrolyte according to claim 1, characterized bythat the functional group for chain polymerization is a carbon-carbon double bond, wherein the functional group for stepwise polymerization is selected from at least one of hydroxyl group, amine group and amide group; wherein the second monomer preferably comprises a diisocyanate monomer; wherein the second monomer preferably comprises a diisocyanate monomer and a diol; wherein the in-situ curing precursor liquid preferably has a viscosity of not more than 10 mPa·S at a temperature of 25°C; wherein the in-situ curing precursor liquid more preferably has a viscosity of not more than 8 mPa·S at a temperature of 25°C; wherein the in-situ curing precursor liquid more preferably has a viscosity of not more than 6 mPa·S at a temperature of 25°C. [3] A process for producing a battery based on an in-situ curing electrolyte according to claim 1 or 2, characterized by that the first monomer is selected from hydroxyl-containing acrylates or hydroxyl-containing acrylamides, in particular comprising at least one of N-hydroxymethylacrylamide, N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)methacrylamide, dihydroxypropyl acrylate and 2,3-dihydroxypropyl methacrylate, and is preferably a hydroxyl-containing acrylate. [4] A process for producing a battery based on an in-situ curing electrolyte according to claim 1 or 2, characterized by that the second monomer is selected from at least one of the following: Diisocyanates, and compositions of a diisocyanate and a diol; wherein the diisocyanates in particular comprise at least one of the following: toluene diisocyanate, hexamethyl diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, polymerized diphenylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, biuret triisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylene diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 1,4-cyclohexyl diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyltolyldimethylene diisocyanate, methylcyclohexyl diisocyanate, decamethylene diisocyanate, 1,12-dodecane diisocyanate, 2,2,4-trimethylcyclohexyl diisocyanate, triphenylmethane triisocyanate, 4,4',4"-triphenylphosphorothioate triisocyanate, cyclohexane dimethylene diisocyanate, 4,4'-Dicyclohexylmethane diisocyanate, polymethylene polyphenyl diisocyanate, 4,4'-diphenyl diisocyanate, norbornene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate,2-Methylpentane diisocyanate, 4,4'-diphenyl ether diisocyanate, 4-methyldiphenylmethane-3,4-diisocyanate, 2,4'-diphenyl sulfide diisocyanate, diethylbenzene diisocyanate, 4,4'-diphenylethane diisocyanate; the diisocyanates are preferably aromatic diisocyanates; wherein the diols are selected from diols containing ether segments and in particular comprise at least one of diethylene glycol, triethylene glycol, tetraethylene glycol and polyethylene glycol, wherein the diols are preferably diethylene glycol, triethylene glycol or tetraethylene glycol; wherein the second monomer is preferably a composition of an aromatic diisocyanate and a low molecular weight diol. [5] A process for producing a battery based on an in-situ curing electrolyte according to claim 1 or 2, characterized bythat the third monomer is selected from at least one of acrylamides, acrylates having a hydroxyl group and acrylates having an isocyanate, which include in particular acrylamide, N-methacrylamide, N-ethylacrylamide, N-isopropylacrylamide, 2-hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 2-(acryloyloxy)ethyl isocyanate and isocyanatoethyl methacrylate, wherein the third monomer is preferably acrylamide. [6] A process for producing a battery based on an in-situ curing electrolyte according to claim 1 or 2, characterized bythat step 1) comprises: the first component, the second component and the third component are added to the electrolyte liquid, which are then subjected to uniform stirring; subsequently, the catalyst, the initiator and a polymerization inhibitor are added; then, further stirring is carried out to obtain the in-situ curing precursor liquid; wherein the polymerization inhibitor is preferably selected from at least one of 1,4-benzoquinone, 2,2-biphenyl-1-picrylhydrazyl, 2-amino-5-nitrobenzophenone, 3-nitroacetophenone, 4-methoxyphenol, N,N-diethylhydroxylamine, tannic acid, phenothiazine, methyl decanoate, galvinoxyl radical; wherein preferably the molar ratio of the first component, the second component and the third component is 1:(2 to 3):(0.3 to 0.8), preferably 1:(2.2 to 2.8):(0.4 to 0.6). [7] A process for producing a battery based on an in-situ curing electrolyte according to claim 6, characterized by that the initiator is selected from at least one of azobisisobutyronitrile, azobisisoheptonitrile, dimethyl 2,2'-azobis(2-methylpropionate), 1-((cyano-1-methylethyl)azo)carboxamide, azodicarbonamide, dicumyl peroxide, di-tert-butyl peroxide, cumyl hydroperoxide, and preferably is 1-((cyano-1-methylethyl)azo)carboxamide, azodicarbonamide, dicumyl peroxide or di-tert-butyl peroxide; wherein preferably the mass of the initiator constitutes 0.5 to 1.5% of the total mass of the first component and the third component; wherein preferably the catalyst is selected from at least one of the following: trialkylphosphine, tertiary amine, quaternary ammonium salt, compounds of the elements of the nitrogen family, organosilicon-phosphorus heteroatom compounds, organometallic compounds and alkaline carboxylates, etc., such as triethylphosphine, pyridine, dimethylphenylphosphine, tris(dimethylaminopropyl)hexahydrotriazine, 2,4,6-tris(dimethylaminomethyl)phenol, trimethyl-N-2-hydroxypropylhexanoic acid, tetramethylammonium octanoate, N-hydroxyalkyl quaternary ammonium base, potassium acetate, triphenylphosphine, tri-n-butylphosphine, lithium acetate, butyllithium, cesium fluoride, tributyltin oxide, tetrabutyl titanate, tetrabutyl zirconate, tin alkoxide, dialkyltin oxide, N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, Triethylenediamine, triethylamine, N,N,N',N'-tetramethylalkylenediamine, N,N-dimethylbenzylamine, N,N-dimethylbutylamine, N,N-dimethylhexadecylamine, N-ethylmorpholine, N-methylmorpholine, N,N-Diethylpiperazine, N,N-Diethyl-2-methylpiperazine, N,N'-Bis(α-hydroxypropyl)-2-methylpiperazine, triethanolamine, N,N-dimethylethanolamine, N,N-lutidine, (dimethylaminoethyl)ether, N-methylethylenediamine, dimethylformamide, triethylenethanediamine, diethyleneglycolamine and triethylenediamine, hexamethyldisilazane, Lithium bistrifluoromethylsulfonimide, lithium bisfluorosulfonimide, potassium carboxylate, tin octoate;, wherein the mass of the catalyst preferably amounts to 0.2 to 0.8%, preferably 0.5%, of the mass of the second component; wherein preferably the total mass of the first component, the second component and the third component amounts to 2 / 98 to 30 / 70, preferably 5 / 95 to 20 / 80, of the mass of the electrolyte. [8] A process for producing a battery based on an in-situ curing electrolyte according to claim 1 or 2, characterized by that the second temperature is higher than the first temperature; wherein the second temperature is preferably at least 10°C higher than the first temperature, more preferably the second temperature is at least 20°C higher than the first temperature, further preferably the second temperature is at least 30°C higher than the first temperature, most preferably the second temperature is at least 40°C higher than the first temperature; wherein the first temperature is preferably 40 to 80 °C, preferably 40 to 60 °C; and wherein the second temperature is 50 to 100 °C, preferably 60 to 90 °C. [9] A battery produced according to a method for producing a battery based on an in-situ curing electrolyte according to any one of claims 1 to 8. [10] In-situ curing electrolyte precursor fluid, characterized byin that the in-situ-curing electrolyte precursor fluid comprises a first component, a second component, a third component, a catalyst, an initiator, and an electrolyte fluid; wherein the first component comprises at least a first monomer, the first monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 2; wherein the second component comprises at least a second monomer, the second monomer capable of copolymerizing with the first monomer; wherein the third component comprises at least a third monomer, the third monomer containing a stepwise polymerization functional group and a chain polymerization functional group, with a stepwise polymerization functionality of 1. [11] In-situ curing electrolyte precursor fluid according to claim 10, characterized by that the first component consists of a first monomer and the second component consists of a second monomer; wherein preferably the functional group for chain polymerization is a carbon-carbon double bond, and the functional group for stepwise polymerization is selected from at least one of hydroxyl group, amine group and amide group; wherein preferably the first monomer is selected from at least one of hydroxyl-containing acrylates or hydroxyl-containing acrylamides; wherein preferably the second monomer is selected from at least one of the following: diisocyanates, and compositions of a diisocyanate and a diol; wherein preferably the third monomer is selected from at least one of acrylamides, acrylates having a hydroxyl group and acrylates having an isocyanate; wherein the in-situ curing electrolyte precursor liquid has a viscosity of not more than 10 mPa·S at a temperature of 25°C; wherein the in-situ curing electrolyte precursor liquid more preferably has a viscosity of not more than 8 mPa·S at a temperature of 25°C; wherein the in-situ curing electrolyte precursor liquid more preferably has a viscosity of not more than 6 mPa·S at a temperature of 25°C; wherein preferably the molar ratio of the first component, the second component and the third component is 1:(2 to 3):(0.3 to 0.8), preferably 1:(2.2 to 2.8):(0.4 to 0.6).

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