Solid electrolyte multilayer membranefor lithium ion battery and preparation method thereof

Abstract

The invention discloses a solid electrolyte multilayer membrane for a lithium ion battery. The solid electrolyte multilayer membrane comprises a solid electrolyte layer and an organic polymer layer, wherein the upper and lower sides of the solid electrolyte layer are respectively provided with organic polymer layers. The solid electrolyte multilayer membrane replaces a traditional polyolefin-basedseparator to improve the lithium ion transmission rate and improve the rate performance of the lithium battery; the solid electrolyte membrane has the excellent heat shrinkage performance at a high temperature, and improves the safety performance of the battery; compared with the conventional composite solid electrolyte membrane, the ratio of solid electrolyte is increased, the electrical conductivity is increased, and the rate performance of the battery is improved; the organic polymer materials on both sides of the three-layer composite structure solid-state electrode membrane can bond theanode and the cathode in the lithium battery, so that the battery core is more firm, and the safety of the battery cores in the transportation and use process is improved.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a solid electrolyte multilayer film for lithium ion batteries and a preparation method thereof. Background technique [0002] Lithium-ion batteries are widely used in mobile communication equipment, notebook computers, digital cameras and other electronic products due to their high energy density, long cycle life and environmental friendliness, and are gradually playing a role in the fields of electric vehicles and energy storage. Currently, the most widely used commercial lithium-ion batteries are assembled using materials such as positive and negative electrodes, liquid electrolytes, and polyolefin separators. Because the liquid electrolyte is flammable and explosive, and the polyolefin separator is easy to shrink or melt when heated, it is easy to cause the battery to short-circuit and explode, which affects the safety of the lithium-ion battery. The solid electroly...

AI Technical Summary

Problems solved by technology

[0003] The battery with organic polymer electrolyte is easy to process and can basically follow the existing lithium-ion battery technology, but the room temperature conductivity is low

Inorganic solid electrolytes have high room temperature conductivity, but the material cost is high, and the battery process is complicated, requiring the development of many new battery production equipment, resulting in a further increase in cost

The composite electrolyte membrane has the easy processability of the organic polymer electrolyte, and can improve the room temperature conductivity to a certain extent, but the poor mechanical strength makes the membrane easy to rupture, resulting in short circuit of the battery, poor compatibility with the positive and negative interfaces, resulting in internal resistance of the battery The shortcomings of high and poor cycle performance, and the room temperature conductivity needs to be further improved

The low solid electrolyte content and high organic polymer content in the existing composite solid electrolyte membrane increase the internal resistance of the battery, resulting in low rate performance of the battery, which is not conducive to the rapid charge and discharge of the battery