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CN-121618033-B - Halide composite solid electrolyte, preparation method thereof, positive plate and battery

CN121618033BCN 121618033 BCN121618033 BCN 121618033BCN-121618033-B

Abstract

The application provides a halide composite solid electrolyte, a preparation method thereof, a positive plate and a battery. The solid electrolyte comprises a porous SiO 2 framework and a halide solid electrolyte, wherein the SiO 2 framework is provided with a continuous and intercommunicated pore canal structure, the halide solid electrolyte is partially filled with the pore canal structure of SiO 2 through in-situ growth, and the halide solid electrolyte is partially wrapped on the surface of the SiO 2 framework through in-situ growth. The interface between the SiO 2 framework and the halide solid electrolyte comprises a transition layer, the mass content of the SiO 2 framework is 1-30wt%, the specific surface area of the framework is 50-500m 2 /g.SiO 2 , the contact area between the halide electrolyte in the pore canal and ambient moisture can be effectively reduced, and the diffusion and permeation of the moisture into the material are delayed. The high bond energy Si-O bonds and the transition layer further inhibit hydrolysis of the halide electrolyte. The halide electrolyte forms a continuous ion transport path within the continuous pore canal of SiO 2 , ensuring high ionic conductivity.

Inventors

  • YANG KAI
  • ZHOU YUNAN
  • DING SHAO
  • LIU JINGCHAO
  • FU XIAOLAN

Assignees

  • 浙江绿色智行科创有限公司
  • 浙江吉利控股集团有限公司

Dates

Publication Date
20260512
Application Date
20260202

Claims (9)

  1. 1. A halide composite solid electrolyte is characterized by comprising a porous SiO 2 framework and a halide solid electrolyte, wherein the porous SiO 2 framework is provided with a continuous and intercommunicated pore channel structure, the halide solid electrolyte is partially filled in the pore channel structure of the porous SiO 2 framework through in-situ growth and is partially wrapped on the surface of the porous SiO 2 framework through in-situ growth, si-O bonds on the surface of the porous SiO 2 framework are used for preferentially capturing water molecules and inhibiting hydrolysis reaction of M-Cl bonds in halide; The interface of the porous SiO 2 framework and the halide solid-state electrolyte comprises a transition layer comprising Si-O-metal bonds; The mass content of the porous SiO 2 framework is 1 to 30wt percent based on the halide composite solid electrolyte; the specific surface area of the porous SiO 2 framework is 50-500m 2 /g; the particle size Dv50 of the porous SiO 2 skeleton is 0.2-0.7 mu m.
  2. 2. The halide composite solid state electrolyte of claim 1, wherein the porous SiO 2 framework has an average pore size of 5-50nm.
  3. 3. The halide composite solid state electrolyte according to claim 1 or 2, wherein the mass content of the porous SiO 2 skeleton is 5wt% to 10wt%.
  4. 4. The halide composite solid state electrolyte according to claim 1 or 2, wherein the porous SiO 2 skeleton is hydrophobic SiO 2 modified with alkyl chains.
  5. 5. The halide composite solid electrolyte according to claim 1 or 2, wherein the halide solid electrolyte has a chemical formula of Li a M x X y , wherein X is one or more selected from chlorine, bromine and iodine, M is one or more selected from Y, in, sc, al, zr, hf, ta, and the values of a, X and y satisfy the stoichiometric number of the valence balance.
  6. 6. The halide composite solid state electrolyte of claim 3, wherein the ionic conductivity is greater than or equal to 0.78 mS/cm and the retention of ionic conductivity is greater than or equal to 85% after 24 hours of exposure to 30% humidity.
  7. 7. A method for producing the halide composite solid electrolyte according to any one of claims 1 to 6, comprising the steps of: Dissolving a raw material of a halide solid electrolyte in an aprotic solvent to prepare a precursor solution; Immersing a porous SiO 2 framework into the precursor solution, and drying after the immersion treatment to obtain an immersion material; And carrying out heat treatment on the impregnating material, wherein the temperature of the heat treatment is 200-500 ℃, the time of the heat treatment is 1-10 h, and the precursor is subjected to in-situ reaction crystallization in the pore canal of the porous SiO 2 framework, so that the halide composite solid electrolyte is obtained.
  8. 8. A positive electrode sheet comprising a current collector, a positive electrode active material, and the halide composite solid electrolyte of any one of claims 1 to 6.
  9. 9. A solid-state battery comprising the positive electrode sheet, the negative electrode sheet, and the solid-state electrolyte according to claim 8.

Description

Halide composite solid electrolyte, preparation method thereof, positive plate and battery Technical Field The application relates to the field of solid-state batteries, in particular to a halide composite solid-state electrolyte, a preparation method thereof, a positive plate and a battery. Background All-solid-state batteries are considered as an important development direction of next-generation energy storage technologies because of their higher safety and energy density. Among them, a halide solid electrolyte (e.g., li 3YCl6、Li3 InCl, etc.) is attracting attention due to its high ion conductivity, excellent oxidation resistance stability, and good compatibility with high-voltage cathode materials. However, most halide electrolytes are extremely sensitive to moisture in the air, and exposure to humid air is susceptible to hydrolysis reactions, resulting in structural failure of the material, a dramatic drop in ionic conductivity, and the potential for corrosive byproducts (e.g., HCl). This inherent air instability severely hampers the mass production, storage and battery assembly process, and becomes a major bottleneck for its commercialization. To improve the air stability of the electrolyte, various strategies have been tried in the industry. One of the main ideas is surface coating, for example by coating the surface of the halide particles with a hydrophobic layer to isolate moisture contact. However, the coating may increase interfacial resistance and the integrity of the coating during long-term cycling is difficult to ensure. Another idea is the modification of elemental doping, such as the incorporation of oxygen elements in the halide electrolyte to enhance air stability. However, direct bulk oxygen doping of halides may improve stability, often at the expense of partial ionic conductivity. Therefore, the development of a novel halide solid electrolyte material with excellent air stability and high ionic conductivity has important practical significance and industrial value. Disclosure of Invention The application provides a halide composite solid electrolyte, a preparation method thereof, a positive plate and a battery, which are used for having air stability and high ionic conductivity. In a first aspect, the application provides a halide composite solid electrolyte, which comprises a porous SiO 2 framework and a halide solid electrolyte, wherein the porous SiO 2 framework is provided with a continuous and intercommunicated pore canal structure, the halide solid electrolyte is partially filled in the pore canal structure of the porous SiO 2 framework through in-situ growth, and the part of the halide solid electrolyte is wrapped on the surface of the porous SiO 2 framework through in-situ growth; the interface between the porous SiO 2 skeleton and the halide solid-state electrolyte comprises a transition layer; The mass content of the porous SiO 2 framework is 1 to 30wt percent based on the halide composite solid electrolyte; The specific surface area of the porous SiO 2 framework is 50-500m 2/g. Further, the average pore diameter of the porous SiO 2 skeleton is 5-50nm. Further, the particle diameter Dv50 of the porous SiO 2 skeleton is 0.2-0.7 μm. Further, the mass content of the porous SiO 2 skeleton is 5wt% to 10wt%. Further, the porous SiO 2 skeleton is hydrophobic SiO 2 modified by alkyl chains. Further, the chemical formula of the halide solid electrolyte is Li aMxXy, wherein X is one or more of chlorine, bromine and iodine, M is one or more of Y, in, sc, al, zr, hf, ta, and the values of a, X and y satisfy the stoichiometric number of valence balance. Further, after the halide composite solid electrolyte is exposed for 24 hours under the humidity of 30%, the ionic conductivity is more than or equal to 0.78 mS/cm, and the retention rate of the ionic conductivity is more than or equal to 85%. In a second aspect, the present application provides a method for preparing the halide composite solid electrolyte according to any one of the first aspects, comprising the steps of: Dissolving a raw material of a halide solid electrolyte in an aprotic solvent to prepare a precursor solution; Immersing a porous SiO 2 framework into the precursor solution, and drying after the immersion treatment to obtain an immersion material; And carrying out heat treatment on the impregnating material, wherein the temperature of the heat treatment is 200-500 ℃, the time of the heat treatment is 1-10 h, and the precursor is subjected to in-situ reaction crystallization in the pore canal of the porous SiO 2 framework, so that the halide composite solid electrolyte is obtained. In a third aspect, the present application provides a positive electrode sheet comprising a current collector, a positive electrode active material, and the halide composite solid electrolyte of any one of the first aspects. In a fourth aspect, the present application provides a battery comprising the positive electrode sheet, the negative el