A high-safety lithium battery core processing process

Abstract

The invention discloses a high-safety lithium battery winding core processing process, by preparing a composite layer material, and processing the winding core with a film or a gasket prepared from the composite layer material to improve the safety performance of the battery, the composite layer The material includes three components: substrate, flame retardant layer and heat absorbing layer, in which the substrate is a film or gasket made of long glass fiber reinforced rubber; the flame retardant layer is a low-temperature hot-melt resin blended with flame retardants; The absorption layer is a coating with good heat absorption performance coated on the surface of the flame retardant layer. The lithium battery core processed by this process can inhibit the internal short circuit of the battery to a certain extent when the battery is subjected to external acupuncture, reduce the risk of fire and explosion of the battery, and significantly improve the safety performance of the lithium battery. The invention has simple process and convenient operation, and can not negatively affect the electrochemical properties such as battery capacity and internal resistance while improving the safety performance of the battery.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a high-safety lithium battery winding core processing process. Background technique [0002] The intensification of environmental pollution and energy crisis has promoted the vigorous development of new energy vehicles. As of December 2014, the sales volume of new energy vehicles in 2014 reached 80,000; among them, the use of high energy density, green and pollution-free, long storage life, no memory effect Pure electric vehicles (EV) and hybrid electric vehicles (HEV) powered by lithium batteries with such advantages are the absolute main force, and they will become the inevitable choice for the future development of the automobile industry. [0003] However, there are certain safety hazards in the application process of power lithium-ion batteries. For example, fire or explosion may occur when the battery is subjected to strong extrusion, acupuncture, short circuit, h...

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Problems solved by technology

[0003] However, there are certain safety hazards in the application process of power lithium-ion batteries. For example, fire or explosion may occur when the battery is subjected to strong extrusion, acupuncture, short circuit, high temperature, etc., which directly threatens the personal and property safety of users. ; At present, improving the safety performance of power lithium batteries has become the focus of attention in the industry

Traditional measures to improve the safety performance of power lithium batteries include using current protection boards, limiting battery operating voltage, adding flame retardant additives to the electrolyte, and setting PTC (thermistor) inside the battery, etc. Although these methods can be used to a certain extent Improve the safety performance of the battery, but it has a certain negative impact on the battery. For example, the current protection board is aimed at the external short circuit of the battery, and is powerless to the internal short circuit of the battery; while limiting the working voltage, it also limits the energy density of the power battery; Flame retardant additives will reduce the conductivity of the electrolyte and increase the internal resistance of the battery; setting PTC inside will have a certain impact on battery design, etc.

At the same time, these protective measures lack sufficient protection against the typical battery external acupuncture. Due to the direct short circuit inside the battery in the case of acupuncture, the surge in current will cause the internal temperature of the battery to increase sharply, increasing the risk of fire and explosion of the battery. Acupuncture raises higher protection requirements

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