Coating for high-temperature-resistant membrane for lithium ion battery and preparation method of high-temperature-resistant membrane

Abstract

The invention discloses a coating for a high-temperature-resistant membrane for a lithium ion battery. The coating consists of the following raw materials in parts by mass: 2,000-5,000 parts of solvent, 0.5-5 parts of dispersant, 5-50 parts of bonding agent and 5-100 parts of high-temperature-resistant non-conducting powder. A preparation method of the high-temperature-resistant membrane comprises the following steps of: (1) adding the solvent and the dispersant into a dispersion machine for uniform dispersing, adding the bonding agent and the high-temperature-resistant non-conducting powder for uniform dispersing into a sizing agent and filtering the sizing agent; and (2) coating the sizing agent on the original membrane by using a coating machine and drying. The high-temperature-resistant membrane for the lithium ion battery prepared with the method can favorably resist heavy punch, puncture and baking, has good safety, and can be applied to occasions with higher safety requirements on batteries.

Description

technical field [0001] The invention relates to a coating for a high-temperature-resistant diaphragm for a lithium-ion battery and a preparation method for a high-temperature-resistant diaphragm. Background technique [0002] The progress of human civilization is always accompanied by the development of energy and material technology. Lithium-ion battery is a milestone in the development of energy technology and material technology. Since M.S.Whittingham of Exxon made the first lithium battery in the 1970s, lithium battery It has attracted worldwide attention, and lithium-ion batteries are developed from lithium batteries. The basic principle of lithium-ion batteries is: when charging, Li + Deintercalation from the positive electrode, intercalation into the negative electrode through the electrolyte, and the opposite when discharging, lithium ions repeatedly move between the positive and negative electrodes during charging and discharging, like a rocking chair, therefore, li...

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Problems solved by technology

[0003] Lithium-ion batteries are widely used in communications and other electronic products due to their high specific energy, small size, and light weight. However, lithium-ion batteries also have potential safety hazards, and cell phone battery explosions are constantly being reported. Disasters and other disasters have caused people to question the safety performance of lithium-ion batteries. Lithium-ion battery separators are an important part of ensuring battery safety performance. The current commercialized polyolefin separators basically meet the safety requirements under normal use, but there is no guarantee that the batteries will be used in the future. Safety under unreasonable working conditions, high-temperature baking, burning, extrusion or puncture of foreign objects will cause great damage to the diaphragm. Once the diaphragm shrinks, melts, or is pierced, it will cause an internal short circuit of the battery, which may cause battery damage. In case of fire, combustion or explosion, it is difficult for ordinary commercialized diaphragms to resist mechanical damage caused by large impact or puncture, and it is also difficult to withstand the high temperature generated by internal short circuit, and the safety performance is not good.

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