Porous membrane reinforced polymer-plastic crystal solid electrolyte membrane, its preparation method and application

Abstract

The invention discloses a porous membrane-reinforced polymer-plastic crystal solid electrolyte membrane, its preparation method and application. The polymer-plastic crystal solid electrolyte membrane includes: a support layer comprising a porous membrane, and a polymer-plastic solid electrolyte layer covering at least one side of the surface of the porous membrane; wherein the porous membrane acts as a support The role of the skeleton, which has a continuous three-dimensional network structure, can improve the mechanical properties of the solid electrolyte membrane, and at the same time, the porous membrane supports the skeleton to facilitate the preparation of a thinner solid electrolyte membrane; the polymer-plastic solid electrolyte layer contains polymer, Lithium salt and plastic crystal compound. By optimizing the ratio of polymer, lithium salt and plastic crystal, a flexible polymer-plastic solid electrolyte membrane with porous membrane enhancement, high voltage resistance, and high low-temperature conductivity can be obtained. The polymer plastic crystal solid electrolyte membrane of the present invention can be applied to all-solid lithium ion batteries, has a simple preparation process and is suitable for industrial production.

Description

technical field [0001] The invention relates to a solid electrolyte membrane, in particular to a porous membrane reinforced, high voltage resistant, high low temperature conductivity, flexible polymer-plastic crystal solid electrolyte membrane, its preparation method and application, belonging to new energy and new material technologies. Background technique [0002] Lithium-ion batteries widely use liquid electrolytes containing organic solvents. These liquid organic solvents are easy to burn, volatilize, and oxidize, especially under extreme working conditions such as overcharge, overdischarge, and high-power charge and discharge, which will generate a lot of heat and accelerate gas. resulting in serious safety hazards. Polymer solid electrolytes are generally made of polymer matrix and inorganic lithium salts. They behave as solids, but they can support the migration of lithium ions like liquids, which can effectively overcome the safety problems of liquid electrolytes s...

AI Technical Summary

Problems solved by technology

However, the polymer-plastic crystal solid electrolyte membrane reported so far has several significant shortcomings that inhibit its wide application in solid lithium batteries: 1. The polymer-plastic crystal solid electrolyte membrane is difficult to build on the premise of self-supporting The lower thickness should be less than 100μm, too thin polymer-plastic crystal solid electrolyte membrane has poor mechanical properties, and thick solid electrolyte membrane greatly increases the volumetric energy density of the battery

2. The melting point of the plastic crystal compound is greatly affected by the concentration of lithium salt added, and the concentration of lithium salt has a great influence on the conductivity of the plastic crystal electrolyte, especially the conductivity at low temperature

However, the ratios of lithium salts, plastic crystal compounds and polymers reported in the literature are often fixed values, and the research on the influence of different ratios on the conductivity and electrochemical performance of polymer-plastic crystal solid electrolyte membranes has not been reported.

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