Thermal shutdown high-temperature-resistant high-safety coating modified diaphragm and preparation method thereof

Abstract

The invention discloses a thermal shutdown high-temperature-resistant high-safety coating modified diaphragm and a preparation method thereof. The thermal shutdown high-temperature-resistant high-safety coating modified diaphragm comprises a coating modified diaphragm body, which comprises a composite coating and two layers of polypropylene base membranes, wherein the two layers of polypropylene base membranes are respectively positioned at the top and the bottom of the polypropylene base membrane, and the thickness of the polypropylene membrane film is 23 nanometers. According to the invention, by using ceramic particles, glass fibers and aluminum oxide, the high-temperature resistance of the coating modified diaphragm can be effectively ensured, and the situation that the use of a battery is affected due to diaphragm damage caused by heating is avoided; and by optimizing the production process, the preparation efficiency is improved, the production cost is reduced, and the problems that the heat resistance of the existing lithium ion battery diaphragm in the market cannot meet the use requirements of people, the lithium ion battery diaphragm is easy to damage in the high-temperature use process to influence the use safety of the battery, the processing technology is complicated, the output cost is relatively high, and the product development and popularization are not facilitated are solved.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery separators, in particular to a thermal shutdown high-temperature resistant high-safety coated modified separator and a preparation method thereof. Background technique [0002] Lithium-ion batteries will release more heat during the charging and discharging process or short circuit, which will cause the local heat accumulation temperature of the battery to rise. In severe cases, the battery may explode. Therefore, the lithium-ion battery separator is used to isolate the positive and negative electrodes of the battery. The key material, firstly, requires the separator to be able to achieve thermal shutdown in the case of thermal runaway of the lithium-ion battery, preventing the ion exchange between the positive and negative electrodes. Negative electrode isolation, preventing positive and negative contact short circuit due to deformation of the diaphragm due to temperature rise. [00...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a heat-shutdown high-temperature resistant high-safety coating modified diaphragm and its preparation method, which has the advantage of simple production and solves the problem that the heat resistance of lithium-ion battery diaphragms in the existing market cannot meet people’s needs. Use requirements, in the process of high temperature use, it is easy to be damaged and affect the safety of the battery, and the processing technology is complicated, and the output cost is high, which is not conducive to product development and promotion.

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