Lithium ion battery containing high-thermal-conductivity and high-conductivity phase change composite material and conductive agent

Abstract

The invention discloses a lithium ion battery containing a high-thermal-conductivity and high-conductivity phase change composite material and a conductive agent. The high-thermal-conductivity and high-conductivity phase change composite material comprises a porous graphene substrate and an oxidized graphene phase change nanocapsule adsorbed in the substrate. The high-thermal-conductivity and high-conductivity phase change composite material provided by the invention has the characteristics of high thermal conductivity and high conductivity of graphene and the characteristic of high thermal conductivity of oxidized graphene, has the advantages of high heat conduction efficiency, high conductive performance and large energy storage capacity, is used in a high-specific-energy lithium ion battery, and can quickly absorb large amounts of heat generated in an abuse test; meanwhile, the oxidized graphene has a flame-retardant effect, so that the safety of the lithium ion battery in the abuse test is greatly enhanced; and moreover, due to the characteristic of high thermal conductivity of the graphene substrate and an oxidized graphene wall material, the heat generated by the high-specific-energy lithium ion battery during use can be effectively diffused, so that the temperature rise of the battery during use is effectively reduced and the service life of the battery is prolonged.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and relates to a lithium-ion battery, in particular, to a lithium-ion battery containing a phase-change composite material with high thermal and electrical conductivity, which is a safe lithium-ion battery that can dissipate heat quickly, and because The temperature rise during the use of the battery is effectively controlled, and the service life of the battery is improved. Background technique [0002] With the continuous development of new energy vehicles, lithium-ion batteries continue to be sought after. At the same time, new energy vehicles also put forward more and more stringent requirements for the battery life, service life and safety performance of lithium-ion batteries. At present, in order to meet the requirements of electric vehicles for cruising range, various lithium-ion battery production units have launched battery technology research on replacing lithium iron phos...

AI Technical Summary

Problems solved by technology

However, although the high specific energy positive electrode material has relatively high energy density, its thermal stability is not ideal, and it is very unsafe to use at high temperature, especially when the internal temperature of the battery is too high during the abuse test, it is difficult to guarantee the safety of the battery. During normal use, the temperature will rise, especially in summer, the battery temperature is high and heat dissipation is slow, which will affect the service life of the battery

[0003] The existing safety technology mainly uses flame retardant additives in the electrolyte, safety valves in the battery structure design, and ceramic diaphragms as measures for flame and explosion protection. However, when the abuse test is performed, the internal temperature of the battery is still too high and cannot be guaranteed Single battery safety

In terms of heat dissipation of the single battery, the structural design of the cover plate is basically optimized, and the heat generation is reduced by reducing the internal resistance of the pole. However, the heat generated by charging and discharging between the internal pole pieces of the single battery cannot be effectively diffused, resulting in the battery operating temperature being still too high. High, ultimately affecting battery life

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