A gel polymer electrolyte precursor, electrolyte, gel battery and method

Abstract

The present invention provides a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method. The gel polymer electrolyte precursor is prepared by dissolving one or more of cyclic siloxane, mono-epoxy-terminated siloxane, and bis-epoxy-terminated siloxane, a catalyst, a lithium salt, a cyclic ether monomer, a cross-linking agent, and a phosphorus-based flame retardant in a carbonate mixed solvent. The above gel polymer electrolyte precursor is subjected to in-situ polymerization for 2 h to 96 h at 0.1 Mpa to 50 Mpa and 20 °C to 80 °C to obtain a gel polymer electrolyte. The above gel polymer electrolyte precursor is injected into a dry battery cell to infiltrate the electrodes and the separator. The infiltrated battery cell is subjected to in-situ polymerization for 2 h to 96 h at 0.1 Mpa to 50 Mpa and 20 °C to 80 °C to obtain a gel battery with an in-situ polymerized gel polymer electrolyte. The precursor solution of the present invention has a low viscosity, is easy to flow, and is convenient to enter into the interior of the electrode sheet in the battery cell, infiltrate the materials, and helps to exert the performance of the battery materials. The safety performance, the capacity performance, and the rate performance of the prepared battery are all improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of gel electrolytes and their batteries, and specifically belongs to gel polymer electrolyte precursors, gel batteries and methods with high safety and high rate performance. Background Art

[0002] To solve the safety problems of flammability and explosibility of high energy density batteries, the current market focuses on developing flame-retardant electrolytes and gel electrolyte technologies, etc. Flame-retardant electrolytes mainly reduce the flammability of electrolyte solvents through flame-retardant additives, thereby improving the safety of the battery. However, the dosage of flame-retardant additives is large, which damages the capacity performance of the battery, and the improvement of battery safety performance is not obvious; gel electrolytes mainly improve the safety performance of the battery by the frame restriction of glue-like substances, enhancing the liquid absorption capacity and the thermal stability of the electrolyte. However, gel electrolytes have high viscosity, reducing the ionic conductivity of the electrolyte, damaging the rate performance of the battery, and reducing the fast charge and discharge ability of the battery. All in all, the currently developed technologies reduce the capacity performance and rate performance of the battery while improving the battery safety performance. Summary of the Invention

[0003] To solve the problems existing in the prior art, the present invention provides a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, which improve the capacity performance and rate performance of the battery while improving the battery safety performance.

[0004] To achieve the above object, the present invention provides the following technical solution: A gel polymer electrolyte precursor, the raw materials include:

[0005] One or more of cyclic siloxane, mono-epoxy-terminated siloxane, bis-epoxy-terminated siloxane, catalyst, lithium salt, cyclic ether monomer, crosslinking agent, phosphorus-based flame retardant;

[0006] The above raw materials are dissolved in a carbonate mixed solvent to prepare a gel polymer electrolyte precursor.

[0007] Further, by mass fraction, the dosage of each raw material is:

[0008] Catalyst 0.1 - 5 parts, lithium salt 5 - 30 parts, cyclic ether monomer component 3 - 40 parts, crosslinking agent 0.5 - 10 parts, phosphorus-based flame retardant 0.5 - 10 parts, carbonate mixed solvent component 60 - 95 parts, cyclic siloxane component 0.5 - 20, mono-epoxy-terminated siloxane 0.2 - 30 parts, bis-epoxy-terminated siloxane 0.2 - 30 parts.

[0009] Further, the cyclic ether monomer is one or more of tetrahydrofuran, 1,3-epoxypentane, trioxane, propylene oxide, epichlorohydrin;

[0010] The crosslinking agent is one or more of ethylene glycol diglycidyl ether, resorcinol diglycidyl ether, polyethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and isocyanuric acid triglycidyl ether.

[0011] Further, the cyclic siloxane is one or more of dimethylcyclosiloxane, trimethylcyclotrisiloxane, hexamethylcyclotrisiloxane, tetramethylcyclotetrasiloxane, and octamethylcyclotetrasiloxane;

[0012] The mono-epoxy-terminated siloxane is one or more of diethoxy(3-glycidyloxypropyl)methylsilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane;

[0013] The bis-epoxy-terminated siloxane is 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane;

[0014] The phosphorus-based flame retardant includes one or more of hexaphenoxycyclotriphosphazene, hexachlorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, tricresyl phosphate, tributyl phosphate, triphenyl phosphate, and tolyldiphenyl phosphate.

[0015] Further, the carbonate mixed solvent is a mixture of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and ethylene carbonate.

[0016] Further, the catalyst is one or more of boron trifluoride and its complexes, tin chloride, trifluoromethanesulfonic acid, phosphorus pentafluoride, lithium hexafluorophosphate, lithium difluorooxalate borate, lithium tetrafluoroborate, azobisisobutyronitrile, benzoyl peroxide, and lauroyl peroxide.

[0017] Further, the lithium salt is one or more of lithium hexafluorophosphate, lithium difluorooxalate borate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, and lithium bis(trifluoromethylsulfonyl)imide.

[0018] The present invention also provides a gel polymer electrolyte, which is obtained by in-situ polymerization of the above gel polymer electrolyte precursor under the conditions of 0.1 Mpa to 50 Mpa and 20 °C to 80 °C for 2 h to 96 h.

[0019] The present invention also provides a gel battery, including:

[0020] A dry battery cell, the dry battery cell includes an electrode and a separator;

[0021] The above gel polymer electrolyte, the gel polymer electrolyte is located inside the dry battery cell, coated outside the electrode particle material and penetrating through the separator voids.

[0022] The present invention also provides a method for preparing a gel battery, comprising:

[0023] S1, injecting the gel polymer electrolyte precursor into a dry battery cell to infiltrate the electrodes and separator in the dry battery cell;

[0024] S2, subjecting the dry battery cell processed in step S1 to in-situ polymerization for 2 h to 96 h under the conditions of 0.1 Mpa to 50 Mpa and 20°C - 80°C to obtain a gel battery with an in-situ polymerized gel polymer electrolyte.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] 1. The present invention provides a gel polymer electrolyte precursor, which has a low solution viscosity, is easy to flow, and is convenient to enter the interior of the electrode sheets in the battery cell to infiltrate the materials, contributing to the performance of the battery materials.

[0027] 2. By copolymerizing substances containing low-polarity siloxane chemical groups such as cyclic siloxane, mono-epoxy-terminated siloxane, and bis-epoxy-terminated siloxane in the polymer electrolyte precursor, the present invention reduces the interaction forces on the electrolyte solvent and lithium ions, thereby reducing the solution viscosity, enhancing the solution fluidity, strengthening the infiltration of the electrode materials, and accelerating the lithium ion transmission rate, improving the rate performance of the battery;

[0028] 3. Through the synergistic cooperation of the silicon element in cyclic siloxane, mono-epoxy-terminated siloxane, and bis-epoxy-terminated siloxane and the phosphorus-based flame retardant, the present invention reduces the dosage of the phosphorus-based flame retardant, helps to reduce the damage to the battery materials, and greatly improves the flame retardancy of the electrolyte, ensuring the safety performance of the battery;

[0029] 4. The present invention uses a cross-linking agent to connect polymer molecules to form a three-dimensional network structure, which has higher chemical and thermal stability, thereby improving the stability of the electrolyte and enabling the battery performance to be exerted stably and for a long time.

[0030] 5. When preparing a gel battery with the gel polymer electrolyte precursor, during the in-situ polymerization of the cyclic ether monomer in the gel polymer electrolyte precursor, the cyclic ether monomer undergoes cationic ring-opening polymerization under the action of a catalyst to generate a polymer, thereby generating a gel electrolyte; during the in-situ polymerization of the gel polymer electrolyte precursor, less heat is generated, the generation rate of the gel polymer is slow, the generated gel polymer has a large molecular weight, a high conversion rate, and uniform polymerization, contributing to the performance and stability of the battery.

[0031] 6. When using the gel polymer electrolyte precursor of the present invention to prepare a gel battery, the gel electrolyte precursor can be in-situ polymerized inside the electrode sheet, generating a gel electrolyte on the electrode material particles. The gel electrolyte coats the electrode particle material and penetrates the diaphragm voids, ensuring the contact between the electrolyte and the electrode material, reducing the internal resistance of the battery. At the same time, the chemical stability of the gel electrolyte is improved by the cross-linking between the molecular chains generated by the monomer polymerization of the gel polymer electrolyte precursor, enhancing the stability of the battery electrolyte. Meanwhile, the gel electrolyte restricts the fluidity of the flame retardant, reducing the side reaction between the flame retardant and the electrode material, jointly improving the cycle ability and capacity performance of the battery. Detailed Embodiments

[0032] The present invention will be further described below in conjunction with the detailed embodiments.

[0033] The present invention provides a gel polymer electrolyte precursor. The precursor solution has a low viscosity, which helps the infiltration of the electrode material, thereby improving the performance of the battery. The gel polymer electrolyte precursor is prepared by dissolving the following raw materials in a carbonate mixed solvent. The raw materials include:

[0034] One or more of cyclic siloxane, mono-epoxy-terminated siloxane, bis-epoxy-terminated siloxane, catalyst, lithium salt, cyclic ether monomer, cross-linking agent, phosphorus-based flame retardant;

[0035] By mass, specifically including: 0.1 - 5 parts of catalyst, 5 - 30 parts of lithium salt, 3 - 40 parts of cyclic ether monomer component, 0.5 - 10 parts of cross-linking agent, 0.5 - 10 parts of phosphorus-based flame retardant, 60 - 95 parts of carbonate mixed solvent component, 0.5 - 20 parts of cyclic siloxane component, 0.2 - 30 parts of mono-epoxy-terminated siloxane, 0.2 - 30 parts of bis-epoxy-terminated siloxane;

[0036] Preferably, the catalyst is one or more of boron trifluoride and its complexes, tin chloride, trifluoromethanesulfonic acid, phosphorus pentafluoride, lithium hexafluorophosphate, lithium difluorooxalate borate, lithium tetrafluoroborate, azobisisobutyronitrile, benzoyl peroxide, dilauroyl peroxide.

[0037] Preferably, the lithium salt is one or more of lithium hexafluorophosphate, lithium difluorooxalate borate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide.

[0038] Preferably, the cyclic ether monomer is one or more of tetrahydrofuran, 1,3-epoxypentane, trioxane, propylene oxide, epichlorohydrin.

[0039] Preferably, the cyclic siloxane is one or more of dimethylcyclosiloxane, trimethylcyclotrisiloxane, hexamethylcyclotrisiloxane, tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane.

[0040] Preferably, the mono-epoxy-terminated siloxane is one or more of diethoxy(3-glycidyloxypropyl)methylsilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0041] Preferably, the bis-epoxy-terminated siloxane is 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane.

[0042] Preferably, the crosslinking agent is one or more of ethylene glycol diglycidyl ether, resorcinol diglycidyl ether, polyethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and isocyanuric acid triglycidyl ether.

[0043] Preferably, the phosphorus-based flame retardant includes one or more of hexaphenoxycyclotriphosphazene, hexachlorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, tricresyl phosphate, tributyl phosphate, triphenyl phosphate, and tolyldiphenyl phosphate.

[0044] Preferably, the carbonate mixed solvent is a mixture of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and ethylene carbonate.

[0045] The present invention also discloses a gel polymer electrolyte, which is obtained by in-situ polymerization of the above gel polymer electrolyte precursor at 0.1 Mpa to 50 Mpa and 20 °C to 80 °C for 2 h to 96 h.

[0046] The present invention also provides a gel battery, including:

[0047] A dry battery cell, which includes an electrode and a separator;

[0048] The above gel polymer electrolyte, the microstructures of the positive electrode and the negative electrode are granular, there are voids on the separator, and the gel polymer electrolyte is located inside the dry battery cell, covering the electrode particle material and penetrating through the voids of the separator so that the electrolyte can conduct ions.

[0049] The specific steps for preparing the above gel battery are as follows:

[0050] 1. Inject the above gel polymer electrolyte precursor solution into the dry battery cell, and infiltrate the electrode and the separator for 2 h to 24 h under vacuum or normal pressure at 20 °C to 60 °C;

[0051] 3. Place the infiltrated battery cell at 0.1 Mpa to 50 Mpa and 20 °C to 80 °C for in-situ polymerization for 2 h to 96 h to obtain a gel battery with an in-situ polymerized gel polymer electrolyte.

[0052] Example 1

[0053] Embodiments of the present invention provide a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0054] Formulation of the gel polymer electrolyte precursor solution:

[0055] In an argon glove box, 0.5 parts of boron trifluoride etherate, 12 parts of lithium hexafluorophosphate, 10 parts of 1,3-epoxypentane, 5 parts of trimethylcyclotrisiloxane, 2 parts of ethylene glycol diglycidyl ether crosslinking agent, 5 parts of diethoxy(3-glycidyloxypropyl)methylsilane, and 5 parts of hexachlorocyclotriphosphazene flame retardant are dissolved in 65 parts of a carbonate mixed solvent, and stirred thoroughly to prepare a gel polymer electrolyte precursor solution;

[0056] Preparation method process of in-situ polymerization of gel battery:

[0057] Inject the gel polymer electrolyte precursor solution into a dry battery cell, and infiltrate the electrodes and the separator. Infiltration is carried out under a vacuum condition, the temperature is 25 °C, and the time is 4 h;

[0058] Then, the battery cell is infiltrated with liquid and polymerized under pressure and temperature. The pressure is 30 MPa, the temperature range is 45 °C, and the time is 6 h, that is, a gel polymer electrolyte battery is prepared by in-situ polymerization.

[0059] The results of testing the NCM811-SiO@C450 battery system by the constant current charge and discharge cycling method: The electrolyte is in a gel state, the battery capacity is 2.0 Ah, the rate is 86% @ 1C, and the cycle is 80% @ 350 cycles.

[0060] Example 2

[0061] Embodiments of the present invention provide a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0062] Solution formulation of the gel polymer electrolyte:

[0063] In an argon glove box, 1 part of tin chloride, 5 parts of lithium hexafluorophosphate, 7 parts of lithium difluorooxalate borate, 10 parts of 1,3-epoxypentane, 5 parts of tetrahydrofuran, 2 parts of dimethylcyclosiloxane, 3 parts of trimethylcyclotrisiloxane, 3 parts of hexamethylcyclotrisiloxane, 1 part of resorcinol diglycidyl ether crosslinking agent, 1 part of polyethylene glycol diglycidyl ether crosslinking agent, 3 parts of 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, 1 part of trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, 2 parts of hexachlorocyclotriphosphazene flame retardant, and 4 parts of hexaphenoxycyclotriphosphazene are dissolved in 60 parts of a carbonate mixed solvent, and stirred thoroughly to prepare a gel polymer electrolyte precursor solution;

[0064] Preparation method process of in-situ polymerization of gel battery:

[0065] Inject the solution into the dry electrode assembly to wet the electrodes and the separator. Under normal pressure, the temperature is 40 °C and the time is 2 h.

[0066] Then, the wet electrode assembly is polymerized under pressure and temperature. The pressure is 50 MPa, the temperature is 80 °C, and the time is 12 h, namely, in-situ polymerization to prepare the gel polymer electrolyte battery.

[0067] The results of testing the NCM811-SiO@C450 battery system by the constant current charge and discharge cycling method are as follows: The electrolyte is in gel state, the battery capacity is 1.9 Ah, the rate is 90% @ 1C, and the cycle is 80% @ 400 cycles.

[0068] Example 3

[0069] The embodiment of the present invention provides a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0070] Solution formulation of the gel polymer electrolyte:

[0071] In an argon glove box, 0.1 part of trifluoromethanesulfonic acid, 5 parts of lithium hexafluorophosphate, 2 parts of lithium tetrafluoroborate, 10 parts of trioxane, 15 parts of propylene oxide, 5 parts of tetramethylcyclotetrasiloxane, 3 parts of hexamethylcyclotrisiloxane, 2 parts of trimethylolpropane triglycidyl ether crosslinking agent, 4 parts of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3 parts of ethoxypentafluorocyclotriphosphazene, and 3 parts of tricresyl phosphate are dissolved in 70 parts of carbonate mixed solvent, and stirred thoroughly to prepare the gel polymer electrolyte precursor solution;

[0072] Preparation process of the in-situ polymerization of the gel battery:

[0073] Inject the solution into the dry electrode assembly to wet the electrodes and the separator. Under normal pressure, the temperature is 20 °C and the time is 2 h.

[0074] Then, the wet electrode assembly is polymerized under pressure and temperature. The pressure is 0.1 MPa, the temperature is 50 °C, and the time is 96 h, namely, in-situ polymerization to prepare the gel polymer electrolyte battery.

[0075] The results of testing the NCM811-SiO@C450 battery system are as follows: The electrolyte is in gel state, the battery capacity is 1.9 Ah, the rate is 86% @ 1C, and the cycle is 80% @ 320 cycles.

[0076] Example 4

[0077] The embodiment of the present invention provides a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0078] Solution formulation of the gel polymer electrolyte:

[0079] In an argon glove box, 0.2 parts of phosphorus pentafluoride, 5 parts of lithium hexafluorophosphate, 7 parts of lithium difluorooxalate borate, 15 parts of epichlorohydrin, 10 parts of tetrahydrofuran, 5 parts of octamethylcyclotetrasiloxane, 3 parts of hexamethylcyclotrisiloxane, 3 parts of isocyanuric acid triglycidyl ether, 3 parts of 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, 1 part of trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, 2 parts of hexachlorocyclotriphosphazene flame retardant, and 4 parts of hexaphenoxycyclotriphosphazene are dissolved in 60 parts of a carbonate mixed solvent, and stirred well to prepare a gel polymer electrolyte precursor solution;

[0080] Preparation process of in-situ polymerization of gel battery:

[0081] Inject the solution into a dry battery cell, and perform wetting of the electrodes and separator. Under normal pressure conditions, the temperature is 20 °C and the time is 24 h;

[0082] Then, the battery cell after wetting by injection is polymerized under pressure and temperature. The pressure is 50 MPa, the temperature is 80 °C, and the time is 2 h, that is, a gel polymer electrolyte battery is prepared by in-situ polymerization.

[0083] Results of testing the NCM811-SiO@C450 battery system: The electrolyte is in a gel state, the battery capacity is 1.7 Ah, the rate is 85% @ 1C, and the cycle is 80% @ 300 cycles.

[0084] Example 5

[0085] The embodiments of the present invention provide a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0086] Formulation of the gel polymer electrolyte precursor solution:

[0087] In an argon glove box, 0.1 part of boron trifluoride diethyl ether, 30 parts of lithium hexafluorophosphate, 3 parts of 1,3-epoxypentane, 20 parts of trimethylcyclotrisiloxane, 0.5 part of ethylene glycol glycidyl ether crosslinking agent, 30 parts of diethoxy(3-glycidyloxypropyl)methylsilane, and 0.5 part of hexachlorocyclotriphosphazene flame retardant are dissolved in 95 parts of a carbonate mixed solvent, and stirred well to prepare a gel polymer electrolyte precursor solution;

[0088] Preparation process of in-situ polymerization of gel battery:

[0089] Inject the gel polymer electrolyte precursor solution into a dry battery cell, and perform wetting of the electrodes and separator. The wetting is carried out under a vacuum condition, the temperature is 30 °C, and the time is 20 h;

[0090] Then, the injected electrolyte infiltrates the battery cell and polymerizes under pressure and temperature. The pressure is 30 MPa, the temperature range is 40 °C, and the time is 12 h, that is, a gel polymer electrolyte battery is prepared by in-situ polymerization.

[0091] The NCM811-SiO@C450 battery system was tested using a constant current charge-discharge cycling method. The results are as follows: The electrolyte is in a gel state, the battery capacity is 1.7 Ah, the rate is 83% @ 1C, and the cycle retention is 80% @ 150 cycles.

[0092] Example 6

[0093] The embodiments of the present invention provide a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0094] Solution formula of the gel polymer electrolyte:

[0095] In an argon glove box, 5 parts of tin chloride, 5 parts of lithium difluorooxalate borate, 40 parts of 1,3-epoxypentane, 0.5 part of dimethylcyclosiloxane, 10 parts of resorcinol diglycidyl ether crosslinking agent, 0.2 part of trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, 2 parts of hexachlorocyclotriphosphazene flame retardant, and 8 parts of hexaphenoxycyclotriphosphazene are dissolved in 60 parts of a carbonate mixed solvent, and stirred thoroughly to prepare a gel polymer electrolyte precursor solution;

[0096] Preparation process of the in-situ polymerization of the gel battery:

[0097] Inject the solution into the dry battery cell, and infiltrate the electrodes and the separator. Under normal pressure conditions, the temperature is 45 °C and the time is 5 h;

[0098] Then, the injected electrolyte infiltrates the battery cell and polymerizes under pressure and temperature. The pressure is 50 MPa, the temperature is 30 °C, and the time is 48 h, that is, a gel polymer electrolyte battery is prepared by in-situ polymerization.

[0099] The NCM811-SiO@C450 battery system was tested using a constant current charge-discharge cycling method. The results are as follows: The electrolyte is in a gel state, the battery capacity is 1.6 Ah, the rate is 86% @ 1C, and the cycle retention is 80% @ 200 cycles.

[0100] Example 7

[0101] The embodiments of the present invention provide a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0102] Solution formula of the gel polymer electrolyte:

[0103] In an argon glove box, 5 parts of tin chloride, 5 parts of lithium difluorooxalate borate, 40 parts of 1,3 - epoxy pentane, 10 parts of resorcinol diglycidyl ether cross - linker, 0.2 parts of 1,3 - bis(3 - glycidyloxypropyl)-1,1,3,3 - tetramethyldisiloxane, 2 parts of hexachlorocyclotriphosphazene flame retardant, and 8 parts of hexaphenoxycyclotriphosphazene are dissolved in 60 parts of a carbonate mixed solvent, and stirred thoroughly to prepare a gel polymer electrolyte precursor solution;

[0104] Preparation method and process of in - situ polymerization of gel battery:

[0105] Inject the solution into a dry battery cell, and infiltrate the electrodes and separator. Under normal pressure conditions, the temperature is 45 °C and the time is 5 h;

[0106] Then, the injected and infiltrated battery cell is polymerized under pressure and temperature conditions. The pressure is 50 MPa, the temperature is 30 °C, and the time is 48 h, that is, a gel polymer electrolyte battery is prepared by in - situ polymerization.

[0107] The results of testing the NCM811 - SiO@C450 battery system by the constant current charge - discharge cycling method: The electrolyte is in a gel state, the battery capacity is 1.8 Ah, the rate is 83% @ 1C, and the cycle is 80% @ 100 cycles.

[0108] Example 8

[0109] The embodiments of the present invention provide a gel polymer electrolyte precursor, an electrolyte, a gel battery and a method, including:

[0110] Formulation of the gel polymer electrolyte precursor solution:

[0111] In an argon glove box, 0.1 part of boron trifluoride diethyl ether, 30 parts of lithium hexafluorophosphate, 3 parts of 1,3 - epoxy pentane, 20 parts of trimethylcyclotrisiloxane, 0.5 part of ethylene glycol diglycidyl ether cross - linker, 30 parts of 1,3 - bis(3 - glycidyloxypropyl)-1,1,3,3 - tetramethyldisiloxane, and 0.5 part of hexachlorocyclotriphosphazene flame retardant are dissolved in 95 parts of a carbonate mixed solvent, and stirred thoroughly to prepare a gel polymer electrolyte precursor solution;

[0112] Preparation method and process of in - situ polymerization of gel battery:

[0113] Inject the gel polymer electrolyte precursor solution into a dry battery cell, and infiltrate the electrodes and separator. Infiltration is carried out under vacuum conditions, the temperature is 30 °C, and the time is 20 h;

[0114] Then, the injected and infiltrated battery cell is polymerized under pressure and temperature conditions. The pressure is 30 MPa, the temperature range is 40 °C, and the time is 12 h, that is, a gel polymer electrolyte battery is prepared by in - situ polymerization.

[0115] Results of testing the NCM811-SiO@C450 battery system using the constant current charge-discharge cycle method: The electrolyte is in a gel state, the battery capacity is 1.8 Ah, the rate is 91% @ 1C, and the cycle is 80% @ 400 cycles.

Claims

1. A gel polymer electrolyte precursor, characterized in that, the raw materials include: one or more of cyclic siloxanes, mono-epoxy-terminated siloxanes, and bis-epoxy-terminated siloxanes, a catalyst, a lithium salt, a cyclic ether monomer, a crosslinking agent, and a phosphorus-based flame retardant; dissolving the above raw materials in a carbonate mixed solvent to obtain a gel polymer electrolyte precursor; in terms of parts by mass, the amounts of each raw material are as follows: 0.1 - 5 parts of the catalyst, 5 - 30 parts of the lithium salt, 3 - 40 parts of the cyclic ether monomer, 0.5 - 10 parts of the crosslinking agent, 0.5 - 10 parts of the phosphorus-based flame retardant, 60 - 95 parts of the carbonate mixed solvent, 0.5 - 20 parts of the cyclic siloxane, 0.2 - 30 parts of the mono-epoxy-terminated siloxane, and 0.2 - 30 parts of the bis-epoxy-terminated siloxane; the cyclic siloxane is one or more of dimethylcyclosiloxane, trimethylcyclotrisiloxane, hexamethylcyclotrisiloxane, tetramethylcyclotetrasiloxane, and octamethylcyclotetrasiloxane; the mono-epoxy-terminated siloxane is one or more of diethoxy(3 - glycidyloxypropyl)methylsilane, trimethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane; the bis-epoxy-terminated siloxane is 1,3-bis(3-glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane.

2. The gel polymer electrolyte precursor according to claim 1, characterized in that, the cyclic ether monomer is one or more of tetrahydrofuran, 1,3-epoxypentane, trioxane, propylene oxide, and epichlorohydrin; the crosslinking agent is one or more of ethylene glycol diglycidyl ether, resorcinol diglycidyl ether, polyethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and isocyanuric acid triglycidyl ether.

3. The gel polymer electrolyte precursor according to claim 1, characterized in that, the phosphorus-based flame retardant includes one or more of hexaphenoxycyclotriphosphazene, hexachlorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, tricresyl phosphate, tributyl phosphate, triphenyl phosphate, and tolyldiphenyl phosphate.

4. The gel polymer electrolyte precursor according to claim 1, characterized in that, the carbonate mixed solvent is a mixture of dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and ethylene carbonate.

5. The gel polymer electrolyte precursor according to claim 1, characterized in that, the catalyst is one or more of boron trifluoride and its complexes, tin chloride, trifluoromethanesulfonic acid, phosphorus pentafluoride, lithium hexafluorophosphate, lithium difluorooxalate borate, lithium tetrafluoroborate, azobisisobutyronitrile, benzoyl peroxide, and lauroyl peroxide.

6. The gel polymer electrolyte precursor according to claim 1, characterized in that, the lithium salt is one or more of lithium hexafluorophosphate, lithium difluorooxalate borate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, and lithium bis(trifluoromethylsulfonyl)imide.

7. A gel polymer electrolyte, characterized in that, It is obtained by in-situ polymerization of the gel polymer electrolyte precursor described in any one of claims 1-6 under the conditions of 0.1 Mpa to 50 Mpa and 20 °C to 80 °C for 2 h to 96 h.

8. A gel battery, characterized in that it includes: a dry battery cell, and the dry battery cell includes an electrode and a separator; the gel polymer electrolyte described in claim 7, and the gel polymer electrolyte is located inside the dry battery cell, coats the electrode particle material, and penetrates the voids of the separator.

9. A method for preparing a gel battery, characterized in that it includes: S1, injecting the gel polymer electrolyte precursor described in any one of claims 1-6 into the dry battery cell to infiltrate the electrode and the separator in the dry battery cell; S2, subjecting the dry battery cell processed in step S1 to in-situ polymerization at 0.1 Mpa to 50 Mpa and 20 °C to 80 °C for 2 h to 96 h to obtain a gel battery having an in-situ polymerized gel polymer electrolyte.