CN-115700941-B - Polymer coated halide solid electrolyte and method for preparing solid battery

CN115700941BCN 115700941 BCN115700941 BCN 115700941BCN-115700941-B

Abstract

The invention discloses a polymer coated halide solid electrolyte and a preparation method of a solid battery, wherein the polymer coated halide solid electrolyte is prepared by dissolving a polymer into an oily solvent to form a solution, adding the halide solid electrolyte into the solution to form a solid electrolyte suspension, and drying the solid electrolyte suspension. The solid-state battery adopts polymer-coated halide solid-state electrolyte to prepare a solid-state electrolyte separation layer. The invention not only can effectively exert the advantages of the halide electrolyte, but also can avoid the problems that the halide solid electrolyte is deliquesced and difficult to dehydrate in the storage and use processes, effectively solves the physical contact problem, improves the ion conducting capability, and solves the problems of poor electrolyte processability, multiple interfaces between materials and high scale cost of the traditional solid-state battery.

Inventors

LI ZHENGZHENG
Tan yingbin
XU LIMIN
WANG JINGJIE
YANG BING

Assignees

宝武碳业科技股份有限公司
宝山钢铁股份有限公司

Dates

Publication Date: 20260505
Application Date: 20210715

Claims (11)

1. A process for preparing the polymer coated halide solid electrolyte includes such steps as dissolving polymer in oily solvent to obtain solution, adding halide solid electrolyte to said solution to obtain solid electrolyte suspension, drying to obtain polymer coated halide solid electrolyte, The polymer is selected from one of PI, PPS, PVDF, PVDF-HFP and PMMA; the oily solvent is selected from one of NMP, tetrahydrofuran, ethylene carbonate and dimethyl carbonate; The halide solid electrolyte is Li a MX b or Li 3 Y 1-c In c X 6 , wherein M is a metal element selected from In, sc, Y, la, X is a halogen element, a is more than or equal to 0 and less than or equal to 10, b is more than or equal to 1 and less than or equal to 13, and c is more than or equal to 0 and less than or equal to 1; in the solution, the concentration of the polymer is 1-15wt%; in the solid electrolyte suspension, the solid content of the halide solid electrolyte is 10-65wt%, The particle size D50 of the polymer-coated halide solid electrolyte is 0.1-10 mu m.
2. The method according to claim 1, wherein, The drying mode is one of spray drying, vacuum drying, hot air drying, infrared drying or microwave drying.
3. The method according to claim 2, wherein, When the drying mode adopts spray drying, the drying temperature is 80-140 ℃ and/or The halide solid electrolyte of Li a MX b is selected from one of Li 3 InCl 6 、Li 3 YCl 6 、Li 3 ScCl 6 or Li 3 InBr 6 .
4. A polymer-coated halide solid electrolyte material, characterized in that the polymer-coated halide solid electrolyte material is produced by the production method of the polymer-coated halide solid electrolyte according to any one of claims 1 to 3.
5. A method for producing a solid-state battery, characterized in that the solid-state electrolyte separator of the solid-state battery is produced by using the polymer-coated halide solid-state electrolyte produced by the method for producing a polymer-coated halide solid-state electrolyte according to any one of claims 1 to 3.
6. The method of manufacturing a solid-state battery according to claim 5, characterized in that the method of manufacturing a solid-state battery comprises the steps of: (1) Preparing a negative electrode plate, namely mixing and pulping a negative electrode material, a conductive agent, a binder, a dispersing agent, a halide solid electrolyte and a non-halide solid electrolyte to obtain a negative electrode slurry, and then coating, drying or roasting to obtain the negative electrode plate; (2) Preparing a solid electrolyte isolation layer, namely adding the polymer-coated halide solid electrolyte and the non-halide solid electrolyte into an oily solvent to obtain electrolyte slurry, then coating the electrolyte slurry on the negative electrode plate in the step (1), and drying and compacting the electrolyte slurry after the electrolyte slurry penetrates into the negative electrode to obtain the negative electrode plate coated with the solid electrolyte isolation layer; (3) Preparing a positive electrode plate, namely adding a positive electrode material, a conductive agent, a polymer-coated halide solid electrolyte, a non-halide solid electrolyte and a dispersing agent into an oily solvent, mixing and pulping to obtain positive electrode slurry, and then coating, drying and compacting to obtain the positive electrode plate; (4) And assembling, namely assembling the positive electrode plate and the negative electrode plate coated with the solid electrolyte isolation layer into a battery core to prepare the solid-state battery.
7. The method of manufacturing a solid-state battery according to claim 6, wherein in the step (1): the negative electrode material is selected from one of graphite and silicon carbon negative electrode material, and/or The conductive agent is selected from one or more of carbon black, carbon nano tube and graphene, and/or The dispersant is selected from CMC, PVP, and/or The halide solid electrolyte is Li a MX b or Li 3 Y 1-c In c X 6 , wherein M is a metal element selected from one of In, sc, Y, la, X is a halogen element, a is more than or equal to 0 and less than or equal to 10, b is more than or equal to 1 and less than or equal to 13, c is more than or equal to 0 and less than or equal to 1, and/or The non-halide electrolyte is a ceramic solid electrolyte, and/or The temperature of the drying or roasting is 50-650 ℃, and/or The concentration of the halide solid electrolyte in the negative electrode slurry is 1-30wt%, and/or The ceramic solid electrolyte is selected from one of LLZO, LLTO, LATP, LAGP.
8. The method of manufacturing a solid-state battery according to claim 6, wherein in the step (2): The non-halide electrolyte is a polymer solid electrolyte and/or a ceramic solid electrolyte, and/or The oily solvent is NMP or tetrahydrofuran, and/or The drying temperature is 90-110 ℃.
9. The method of producing a solid-state battery according to claim 8, wherein in the step (2) and/or the step (3): the polymer solid electrolyte is selected from one of PEO, PVDF-HFP or PMMA, and/or The ceramic solid electrolyte is selected from one of LLZO, LLTO, LATP or LAGP.
10. The method of manufacturing a solid-state battery according to claim 6, wherein in the step (3): the positive electrode material is selected from one of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate and lithium manganese oxide, and/or The conductive agent is selected from one or more of carbon black, carbon nano tube and graphene, and/or The non-halide solid electrolyte is a polymer solid electrolyte and/or a ceramic solid electrolyte, and/or The dispersant is selected from CMC, PVP, and/or The oily solvent is selected from NMP or tetrahydrofuran.
11. A solid state lithium ion battery, characterized in that it is produced by the solid state battery production method according to any one of claims 5 to 10.

Description

Polymer coated halide solid electrolyte and method for preparing solid battery Technical Field The invention belongs to the field of lithium batteries, and particularly relates to a polymer-coated halide solid electrolyte and a preparation method of a solid battery. Background The solid-state battery is the battery which is most likely to inherit the position of the lithium ion battery in recent years, and the solid-state electrolyte is adopted to replace electrolyte in the past lithium battery as a conducting substance, so that the energy density of the battery can be greatly improved, and the problems of short circuit, severe flammable and explosive solvent side reaction and the like caused by dendrite which are easy to generate in the traditional liquid battery are avoided; the solid electrolyte is key to the large-scale application of the solid battery, and not only has excellent electrochemical performance, but also has chemical stability and mechanical processing performance which can be matched with the large-scale production process. In the prior art, the main solid electrolyte has high sulfide ion conductivity but poor chemical stability, ceramic solid electrolyte systems such as oxides and the like relate to complexity, the mechanical processing performance is poor, the physical contact problem is difficult to solve, the thermodynamic stability of borohydride, the suitability between the borohydride and positive and negative electrodes, the capability of inhibiting dendrite growth and the like are insufficient, the polymer solid electrolyte needs to operate at a high temperature and has weak ion conducting capability, and therefore, the scale, the production cost and the comprehensive performance of the solid battery are difficult to break through. The halide solid electrolyte has high ionic conductivity, stable chemical/electrochemical stability and good plasticity, has ionic conductivity of more than 10 -3S·cm-1 at room temperature, shows good thermal and electrochemical stability, has good compatibility with various interfaces, is a solid electrolyte material with higher plasticity, and has great potential in the field of lithium ion batteries, in particular to the field of solid batteries, wherein the halide solid electrolyte can be prepared by mechanical ball milling and calcination and has higher ionic conductivity. The halide solid electrolyte has high stability, can be used as an excellent buffer layer between a high-voltage positive electrode and other electrolyte materials, and is an excellent negative electrode protective layer material for materials with weaker easily-conductive ions, such as graphite. However, the halide electrolyte has the characteristic of deliquescence, crystal water is easy to form to lead the ionic conductivity to drop sharply, and the drying dehydration temperature is higher than 200 ℃, which conflicts with the tolerance temperature of the binder in the pole piece, thus limiting the large-scale engineering application of the material. In view of the above, there is a need in the industry to develop a new halide solid electrolyte, which not only can effectively play the advantages of the halide electrolyte, but also can avoid the problems that the halide solid electrolyte is deliquescent and difficult to dehydrate during storage and use, effectively solve the physical contact problem, and improve the ion conducting capability, thereby solving the above-mentioned series of engineering application problems of the solid battery. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a polymer-coated halide solid electrolyte, and a method for preparing a solid battery, in which the polymer-coated halide solid electrolyte is prepared by coating a halide electrolyte material with a polymer, and the polymer-coated halide solid electrolyte is used in combination with water and an oily solvent to form a solid battery which is easy to manufacture and has excellent performance, so that not only can the advantages of the halide electrolyte be effectively exerted, but also the problems of deliquescence and difficult dehydration of the halide solid electrolyte during storage and use can be avoided, the physical contact problem can be effectively solved, and the ion conducting capability can be improved, thereby solving the problems of poor electrolyte processability, multiple interfaces between materials and high scale cost of the existing solid battery. In order to achieve the above purpose, the invention adopts the following technical scheme: According to a first aspect of the invention, there is provided a method of preparing a polymer-coated halide solid electrolyte, comprising dissolving a polymer in an oily solvent to form a solution, adding the halide solid electrolyte to the solution to form a solid electrolyte suspension, and drying the solid electrolyte suspension to obtain the polymer-coate