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CN-121983658-A - High-temperature-resistant composite solid electrolyte and preparation method and application thereof

CN121983658ACN 121983658 ACN121983658 ACN 121983658ACN-121983658-A

Abstract

The invention relates to the technical field of solid-state batteries, in particular to a high-temperature-resistant composite solid-state electrolyte, a preparation method and application thereof, wherein the preparation method of the high-temperature-resistant composite solid-state electrolyte comprises the steps of mixing a monomer solution obtained by mixing a polymer monomer containing ester groups with a polymer monomer containing urea groups or sulfonamide groups with lithium salt and oxide electrolyte to obtain precursor slurry; and mixing the precursor slurry with a thermal initiator, injecting the mixture into a mold, and performing in-situ curing treatment to obtain the high-temperature-resistant composite solid electrolyte. The polymerized monomer containing the ester group has good thermal stability and is responsible for forming a flexible network, so that the ionic conductivity is ensured, the polymerized monomer containing the urea group or the sulfonamide group can strengthen the acting force between chains by establishing a hydrogen bond network, and the double-monomer system can inhibit the movement of molecular chains at high temperature, so that the structural stability is improved; the high-temperature-resistant composite solid electrolyte has excellent thermal stability, high-performance electrochemical circulation and wide-temperature-range working capacity.

Inventors

  • WANG JUN
  • YU KAI
  • XU XIAOXIONG
  • CHI SHANGSEN
  • DENG YONGHONG
  • LIU CHUNYU

Assignees

  • 南方科技大学

Dates

Publication Date
20260505
Application Date
20260108

Claims (10)

  1. 1. The preparation method of the high-temperature-resistant composite solid electrolyte is characterized by comprising the following steps of: mixing a polymerized monomer containing an ester group with a polymerized monomer containing an ureido or sulfonamide group to obtain a monomer solution; mixing the monomer solution with lithium salt and oxide electrolyte to obtain precursor slurry; and mixing the precursor slurry with a thermal initiator, injecting the mixture into a mold, and performing in-situ curing treatment to obtain the high-temperature-resistant composite solid electrolyte.
  2. 2. The method for preparing a high temperature resistant composite solid electrolyte according to claim 1, wherein the polymer monomer containing ester groups comprises at least one of ethylene carbonate, methyl methacrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, vinyl acetate and vinyl propionate.
  3. 3. The method for preparing the high-temperature-resistant composite solid electrolyte according to claim 1, wherein the polymeric monomer containing ureido comprises at least one of 1, 3-diallyl urea, ureidoethyl methacrylate, ureidoethyl acrylate, N- (2-acryloyloxyethyl) ethylene urea, N- (2-methacryloyloxyethyl) ethylene urea, N-methacrylamidomethylethylene urea, N-methacrylamidoethylethylene urea and N- (3-allyloxy-2-hydroxypropyl) aminoethylethylene urea, and the polymeric monomer containing sulfonamide comprises at least one of 4-vinylbenzenesulfonamide, N-allylp-toluenesulfonamide and N-methylvinylsulfonamide.
  4. 4. The method for preparing a high temperature resistant composite solid electrolyte according to claim 1, wherein the polymer monomer containing ester groups accounts for 50% -95% of the total mass of the precursor slurry.
  5. 5. The method for preparing a high temperature resistant composite solid electrolyte according to claim 1, wherein the polymerized monomer containing urea group or sulfonamide group accounts for 1% -10% of the total mass of the precursor slurry.
  6. 6. The method for preparing the high-temperature-resistant composite solid electrolyte according to claim 1, wherein the oxide electrolyte is LLZO-based solid electrolyte, and the oxide electrolyte accounts for 5% -40% of the total mass of the precursor slurry; preferably, the LLZO-based solid state electrolyte includes at least one of Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 、Li 6.4 La 3 Zr 1.4 Nb 0.6 O 12 .
  7. 7. The method for preparing a high temperature resistant composite solid electrolyte according to claim 1, wherein the lithium salt is one or more selected from the group consisting of lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (difluorosulfonimide), lithium bis (trifluoromethylsulfonimide), lithium bis (oxalato) borate, and lithium difluoro (oxalato) borate; preferably, the lithium salt accounts for 1% -2% of the total mass of the precursor slurry.
  8. 8. The method for preparing a high temperature resistant composite solid electrolyte according to claim 1, wherein the temperature of the in-situ curing treatment is 60 ℃ to 100 ℃, and the time of the in-situ curing treatment is 12h to 24h.
  9. 9. A high temperature resistant composite solid electrolyte prepared by the method of preparing a high temperature resistant composite solid electrolyte according to any one of claims 1 to 8.
  10. 10. Use of the high temperature resistant composite solid state electrolyte of claim 9 in an all solid state lithium metal battery.

Description

High-temperature-resistant composite solid electrolyte and preparation method and application thereof Technical Field The invention relates to the technical field of solid-state batteries, in particular to a high-temperature-resistant composite solid-state electrolyte, and a preparation method and application thereof. Background With the rapid development of electric vehicles and large-scale energy storage systems, lithium ion batteries with high energy density and high safety are becoming research hotspots. Although the traditional liquid electrolyte lithium ion battery has high ionic conductivity and good interface contact, potential safety hazards such as easy leakage, inflammability and explosion exist, and especially under a high-temperature environment, an organic solvent is easy to decompose, so that the battery performance is attenuated and even thermal runaway is caused. As an alternative, the solid electrolyte can significantly improve battery safety by conducting lithium ions through the solid material. At present, the main stream solid electrolyte technical route comprises a polymer, an oxide and a sulfide system, but all suffer from the bottleneck problems of insufficient high-temperature stability, high interface impedance, complex preparation process and the like. The liquid electrolyte is usually formed by dissolving lithium salt (such as LiPF 6) in carbonate solvent (such as EC/DMC), and has high ionic conductivity (up to 10 -3 S/cm at normal temperature), but low boiling point, poor thermal stability and extremely unstable at high temperature. Polymer electrolytes (such as polyethylene oxide PEO) are widely studied for good flexibility and interfacial compatibility, but their intrinsic ionic conductivity is low, only 10 -8~10-6 S/cm at room temperature, limiting their application at room temperature. In addition, the polymer chain segment is easy to degrade at high temperature, and has poor thermal stability (degradation usually occurs below 100 ℃), so that the electrolyte is easy to fail at high temperature, and the application of the polymer chain segment in a high-temperature environment is limited. Oxide electrolytes (e.g., garnet-type Li 7La3Zr2O12, LLZO) have excellent high-temperature stability and a wide electrochemical window, but their rigid interfaces are poorly contacted with electrode materials and are difficult to process. The prior study improves the interface performance through surface coating, but the coating layer is easy to lose efficacy at high temperature, and the thermal expansion coefficient of the composite system is not matched. Sulfide (e.g., li 6PS5 Cl) and halide (e.g., li 3YCl6) electrolytes have room temperature ionic conductivities approaching those of liquid electrolytes (> 10 -3 S/cm), but sulfide is sensitive to water oxygen (generating H 2 S toxic gases), halide is costly and not stable enough. The conventional Gao Wenshi formula is required to rely on a complex packaging technology, and interface side reactions are aggravated at high temperature, so that the battery performance is quickly attenuated, and the requirements of high-temperature stability, wide-temperature-range operation and long-acting circulation are difficult to be met. Accordingly, the prior art is still in need of improvement and development. Disclosure of Invention In view of the shortcomings of the prior art, the invention aims to provide a high-temperature-resistant composite solid electrolyte, a preparation method and application thereof, and aims to solve the problems that the existing solid electrolyte cannot be compatible with high-temperature stability, wide-temperature-range operation and long-acting circulation. The technical scheme of the invention is as follows: a preparation method of a high-temperature-resistant composite solid electrolyte comprises the following steps: mixing a polymerized monomer containing an ester group with a polymerized monomer containing an ureido or sulfonamide group to obtain a monomer solution; mixing the monomer solution with lithium salt and oxide electrolyte to obtain precursor slurry; and mixing the precursor slurry with a thermal initiator, injecting the mixture into a mold, and performing in-situ curing treatment to obtain the high-temperature-resistant composite solid electrolyte. The preparation method of the high-temperature-resistant composite solid electrolyte comprises the step of preparing the high-temperature-resistant composite solid electrolyte, wherein the polymer monomer containing ester groups comprises at least one of ethylene carbonate, methyl methacrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, vinyl acetate and vinyl propionate. The preparation method of the high-temperature-resistant composite solid electrolyte comprises the steps that the polymer monomer containing ureido comprises at least one of 1, 3-diallyl urea, ureidoethyl methacrylate, ureidoethyl acrylate, N- (2-acryloyloxyethyl) ethylene urea, N-