Battery heating film with variable heating power, and lithium ion battery

Abstract

The embodiment of the invention provides a battery heating film with variable power, and a lithium ion battery. The battery heating film with variable power comprises an upper insulating coating layer, a lower insulating coating layer and a heating layer arranged between the upper insulating coating layer and the lower insulating coating layer, the heating layer comprises a plurality of heating loops, and the plurality of heating loops are composed of resistance wires and leading-out wires. The leading-out wires are arranged at the end parts and the middle parts of the resistance wires. According to the technical scheme, the battery in a low-temperature environment is heated through the battery heating film, so that the working range of the battery is expanded; the variable heating power realized by adopting the plurality of heating loops and a switching-on method can quickly reach the optimal working temperature of the battery with the most suitable heating power and heating resistance value in different low-temperature ranges; the heating loops are reasonably distributed in the heating film, so that the heating uniformity of the heating film under different heating powers is ensured; and the resistance wires forming the heating loops can be different in thickness, namely resistance wires with different resistance values, according to different battery models.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a battery heating film with variable heating power and a lithium ion battery. Background technique [0002] In a low temperature environment, due to the slow diffusion of lithium ions inside the lithium-ion power battery, the decrease of ionic conductivity in the electrolyte, the increase of internal contact resistance and the slowdown of various chemical reaction rates, etc., lead to the charging of the battery. The discharge capacity and usable capacity are rapidly attenuated. Especially in a low temperature environment, it will lead to the occurrence of lithium precipitation, and the growth of lithium dendrites to a certain extent will puncture the diaphragm, resulting in some safety accidents. In order to avoid these accidents, electric heating films have been widely used in power battery systems. [0003] Most of the current heating films are composed of a single heati...

AI Technical Summary

Problems solved by technology

The resistance wires are arranged in a serpentine shape, but there is no mention of the use of filling materials between the resistance wires, which will lead to contact between the resistance wires under extreme working conditions and reduce the reliability of the heating film; at the same time, the heating film There are only two heating circuits, and the variable power that can be realized is small, so it is difficult to adapt to the complex low temperature environment

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