Lithium-ion battery diaphragm with high melting temperature as well as preparation method thereof

Abstract

The invention discloses a lithium-ion battery diaphragm with high melting temperature as well as a preparation method thereof. The diaphragm is formed by compounding an ETFE (ethylene-tetrafluoroethylene) microporous membrane and a PE (polyethylene) microporous membrane. The preparation method comprises the following steps: preparing a diaphragm from ETFE and PE respectively by a thermally induced phase separation method, and extracting a diluent by A/B/A three-layer coextrusion curtain coating and compounding as well as bidirectional stretching, thereby preparing the lithium-ion battery diaphragm, wherein the layer A is the ETFE microporous membrane; the layer B is a PE microporous membrane. The lithium-ion battery diaphragm provided by the invention is high in melting temperature and mechanical intensity, is low in obturator temperature, and can practically and effectively improve the safety of the lithium ion battery.

Description

technical field [0001] The invention relates to the research field of lithium-ion battery separators, in particular to a lithium-ion battery separator with a high fusing temperature and a preparation method thereof. Background technique [0002] Environmental pollution and energy crisis have attracted widespread attention from all over the world. The new energy industry, represented by the new energy automobile industry and the energy storage industry, has received full support from the governments of major countries and regions around the world. Among them, the lithium-ion battery is the core component of the new energy industry, and its importance is self-evident. [0003] Lithium-ion batteries are mainly composed of positive and negative electrode materials, electrolytes and separators. The separator is an important part of the lithium-ion battery. Its main functions are: 1. To isolate the positive and negative electrodes and prevent the electrons in the battery from pa...

AI Technical Summary

Problems solved by technology

However, since the PTFE-based film cannot be prepared by the commonly used extrusion processing method, the preparation process of the composite film is cumbe...