Cooling system of electric vehicle lithium battery

Abstract

The invention relates to a cooling system of an electric vehicle lithium battery. The cooling system comprises a lithium battery pack and a water-cooling system, wherein the lithium battery pack comprises single lithium batteries, the water-cooling system is used for integrally cooling the lithium battery pack, the single lithium battery comprises a dual-separator layer, the dual-separator layer is used for isolating a positive electrode and a negative electrode of the single lithium battery, chlorinated paraffin is injected to the dual-separator layer, a hot pipe is inserted into a middle part of the dual-separator layer, a hot pipe of each single lithium battery extends out of one end of the single lithium battery and is connected to the water-cooling system, a phase changing material wraps the periphery of the single lithium battery so as to absorb heat discharged from the single lithium battery, the heat can be stored in a latent heat form, and meanwhile, a heat preservation effectunder a low-temperature environment achieved. By the cooling system, a hot heat region of the lithium battery is enabled to be cooled to the maximum extent, other regions are cooled to a normal extent, so that different regions of an electric vehicle lithium battery obtains different cooling capability effects, meanwhile, the single batteries are preserved, the working of the battery working a cold region is maintained, and the pre-heating link is reduced.

Description

technical field [0001] The invention relates to an electric vehicle lithium battery, in particular to a cooling system for the electric vehicle lithium battery. Background technique [0002] In recent years, pure electric vehicles and hybrid vehicles have stood out in the transportation industry. They have obvious advantages in environmental protection and energy saving, and are suitable for long-term solutions to future transportation. However, the thermal management of batteries has become a bottleneck in the commercialization of electric vehicles. Large-scale battery packs will generate a lot of heat during rapid charge-discharge cycles, accompanied by different chemical and electrochemical reactions, leading to risks such as overheating, combustion and explosion. In addition, the increase in temperature and temperature difference in the battery pack will significantly reduce its cycle life, requiring effective heat dissipation and local thermal control. In addition, if ...

AI Technical Summary

Problems solved by technology

The heat dissipation of the traditional battery pack is mainly by increasing the flow rate of the fan to improve the heat dissipation effect of the lithium battery. This method consumes a lot of resources and cannot achieve uniform heat dissipation of the lithium battery.

[0003] In the traditional heat dissipation system, in addition to simply using air cooling, some have adopted two or more lithium battery boxes, the first heat dissipation rib and the first heat pipe for heat dissipation, and are connected to two or more lithium batteries through the first heat dissipation rib. The outer wall of the box is connected to the first heat dissipation rib on the outside of two or more lithium battery boxes through the first heat pipe. The air duct design is adopted between the single batteries to achieve uniform heat dissipation of the lithium battery. There are very high requirements, and because it is difficult to make the flow field consistent, the temperature consistency of the battery cells is not good, and the battery may need to be preheated when used in cold areas or cannot be used in extremely cold areas

In addition, when the diaphragm of the lithium battery is overcharged or the temperature rises, the diaphragm is easily broken down, causing accidents such as thermal runaway or even explosion.

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