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CN-122025784-A - Flame-retardant polymer electrolyte material based on Lewis acid-base synergistic regulation and preparation method thereof

CN122025784ACN 122025784 ACN122025784 ACN 122025784ACN-122025784-A

Abstract

The invention relates to a flame-retardant polymer electrolyte material based on Lewis acid-base synergistic regulation and a preparation method thereof. A preparation method of a flame-retardant polymer electrolyte material based on the synergistic regulation of Lewis acid and alkali comprises the steps of mixing a compound containing a boric acid ester segment, a compound containing a phosphate ester segment, a crosslinking agent and lithium salt, adding an initiator, and carrying out polymerization reaction to obtain the flame-retardant polymer electrolyte material. According to the flame-retardant polymer electrolyte material based on the synergistic regulation of Lewis acid and alkali and the preparation method thereof, three functional molecular fragments are covalently crosslinked through in-situ free radical copolymerization to construct a three-dimensional network, so that the flame-retardant, high-ion-conductivity and stable-interface all-solid-state polymer electrolyte is obtained.

Inventors

  • LI NANA
  • LI CHENGLIN
  • ZHANG XIAOKANG
  • XU QI
  • SHEN YANBING

Assignees

  • 石河子大学

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. The preparation method is characterized in that a compound containing a boric acid ester segment, a compound containing a phosphate ester segment, a cross-linking agent and lithium salt are mixed, and then an initiator is added for in-situ polymerization reaction, so that the flame-retardant polymer electrolyte material is obtained.
  2. 2. The method according to claim 1, wherein, The compound containing the borate fragment is one of allylboronic acid pinacol ester, propenyl diisopropyl borate and butyl-1-alkene-4-boronic acid pinacol ester; The compound containing the phosphate segment is one of 3-butenyl phosphoethyl carboxylate, 2- (diethoxy phosphoryl) allyl acetate, 2-methacrylic acid ethoxyethyl phosphate, vinyl diethyl phosphate and polyphosphoryl ethylene glycol acrylate; the cross-linking agent is at least one of 1, 4-butanediol diacrylate, diallyl phthalate, N '-methylene bisacrylamide, N' -methylene bisacrylamide, diallyl isocyanurate, 1,3, 5-triallyl-1, 3, 5-triazine-2, 4,6 (1H, 3H, 5H) -trione and 1, 3-diallyl urea.
  3. 3. The method according to claim 2, wherein, The molar ratio of the compound containing the borate fragment to the compound containing the phosphate fragment to the crosslinking agent is 1:1-10:0.2.
  4. 4. The method according to claim 1, wherein, The lithium salt is at least one of lithium hexafluorophosphate, lithium perchlorate, lithium bis (trifluoromethanesulfonyl) imide, lithium bis (fluorosulfonyl) imide, lithium bis (oxalato) borate and lithium difluoro (oxalato) borate; The molar mass ratio of the lithium salt to the compound containing the borate fragment, the compound containing the phosphate fragment and the crosslinking agent is 1mol/g.
  5. 5. The method according to claim 1, wherein, The initiator is a thermal initiator; the temperature of the in-situ polymerization reaction is 65-70 ℃.
  6. 6. The method according to claim 5, wherein, The thermal initiator is 2,2' -azobis (isobutyronitrile); the in-situ polymerization reaction is carried out by mixing for 2h at 65 ℃ and then reacting for 6h at 70 ℃.
  7. 7. The method according to claim 5, wherein, The amount of the thermal initiator is 0.8-1.2wt% of the compound containing the borate fragment, the compound containing the phosphate fragment and the crosslinking agent.
  8. 8. A flame-retardant polymer electrolyte material based on the synergistic regulation of Lewis acid and alkali, which is characterized by being prepared by the preparation method of any one of claims 1-7.
  9. 9. A polymer solid state battery comprising the lewis acid base based synergistically regulated flame retardant polymer electrolyte material of claim 8.
  10. 10. The polymer solid state battery according to claim 9, wherein the polymer solid state battery further comprises a positive electrode material and a negative electrode active material; Wherein the positive electrode material is one or more of LiNi x Co y M 1-x-y O 2 、LiCoO 2 、LiMn 2 O 4 、LiFePO 4 , M in LiNi x Co y M 1-x-y O 2 is Mn or Al,0.2< x <0.9,0.1< y <0.5; the negative electrode active material is metallic lithium or lithium alloy.

Description

Flame-retardant polymer electrolyte material based on Lewis acid-base synergistic regulation and preparation method thereof Technical Field The invention belongs to the technical field of new energy materials, and particularly relates to a flame-retardant polymer electrolyte material based on Lewis acid-base synergistic regulation and a preparation method thereof. Background With the rapid development of electric vehicles and aviation industry, the demand for high energy density batteries has proliferated. Conventional graphite negative electrode lithium ion batteries have difficulty meeting this requirement. Lithium metal anodes are critical for increasing energy density due to their low redox potential (-3.04V vs. Standard hydrogen electrode) and high specific capacity (3830 mAh/g). However, liquid Electrolyte (LE) based Lithium Metal Batteries (LMB) present the risk of lithium dendrite growth runaway, short cycle life and thermal runaway, the root causes of which are (1) imbalanced interfacial ion distribution: LEDynamic reconstruction of solvated sheath impedes interfacial migration leading to concentration gradient collapse (2) Space Charge Layer (SCL) distortion, anion dissipation induces local electric field enhancement, drivingAnd (3) SEI layer heterogeneity, namely cracking of the SEI layer formed by solvated sheath decomposition aggravates uneven interface flux and accelerates dendrite growth. While polymer electrolytes (e.g., polyester-based) can reduce leakage risk, but still face three major bottlenecks, namely high ion pair binding energy due to low dielectric constant, difficult cleavage of lithium salt, polarization induced by anion migration dominance, and lithium ion migration count) Low side reaction to lithium metal, poor interface stability and incomplete solution of flammability. While various targeting strategies have been proposed to overcome these drawbacks, including adding inorganic fillers, mixing organic materials, editing molecular structures, forming gel electrolytes by combining with liquid electrolytes and designing new salts, these strategies have certain limitations in practical applications. They still cannot achieve excellent lithium salt dissociation capability and high levels at the same timeStable lithium metal properties, high voltage stability and excellent flame retardancy. Thus, there is a strong need for a simple, scalable strategy to improve the overall performance of polyester-based solid state electrolytes. In view of the above, the present invention provides a new electrolyte material, which is a flame-retardant polymer electrolyte material based on the synergistic regulation of lewis acid and alkali, and is an all-solid polymer electrolyte capable of realizing flame retardance, high ion conductivity and stable interface through the synergistic effect of lewis acid and alkali, and suitable for high energy density lithium metal batteries (such as electric automobiles and aircraft power systems). Disclosure of Invention The invention aims to provide a preparation method of a flame-retardant polymer electrolyte material based on Lewis acid-base cooperative regulation, which adopts a strategy of 'Lewis acid-base cooperative regulation', and constructs a flame-retardant polymer electrolyte (BE-P-Es) with a ternary molecular fragment covalently crosslinked through in-situ polymerization, so as to synchronously solve the bottleneck. In order to achieve the above purpose, the technical scheme adopted is as follows: A preparation method of a flame-retardant polymer electrolyte material based on the synergistic regulation of Lewis acid and alkali comprises the steps of mixing a compound containing a boric acid ester segment, a compound containing a phosphate ester segment, a crosslinking agent and lithium salt, adding an initiator, and carrying out in-situ polymerization reaction to obtain the flame-retardant polymer electrolyte material. Further, the compound containing the borate fragment is one of allyl boric acid pinacol ester, propenyl boric acid diisopropyl ester and butyl-1-alkene-4-boric acid pinacol ester; The compound containing the phosphate segment is one of 3-butenyl phosphoethyl carboxylate, 2- (diethoxy phosphoryl) allyl acetate, 2-methacrylic acid ethoxyethyl phosphate, vinyl diethyl phosphate and polyphosphoryl ethylene glycol acrylate; the cross-linking agent is at least one of 1, 4-butanediol diacrylate, diallyl phthalate, N '-methylene bisacrylamide, N' -methylene bisacrylamide, diallyl isocyanurate, 1,3, 5-triallyl-1, 3, 5-triazine-2, 4,6 (1H, 3H, 5H) -trione and 1, 3-diallyl urea. Still further, the molar ratio of the borate fragment-containing compound, the phosphate fragment-containing compound and the crosslinking agent is 1:1-10:0.2. Further, the lithium salt is at least one of lithium hexafluorophosphate, lithium perchlorate, lithium bistrifluoromethane sulfonyl imide, lithium bisoxalato borate and lithium difluorooxalato borate; The molar ma