Multi-modal phase-change thermal balance system for lithium battery pack of electric vehicle

Abstract

The invention relates to a multi-modal phase-change thermal balance system for a lithium battery pack of an electric vehicle. The multi-modal phase-change thermal balance system comprises a gas liquid phase-change heat conducting channel comprising a gas liquid phase-change material; the gas liquid phase-change heat conducting channel comprises at least one extension channel and column cylinders for accommodating lithium cells; the hollow wall bodies of all column cylinders are connected with the extension channel; the outer side wall of each lithium cell is suitable for being in tight fit with the inner wall of the corresponding column cylinder, or the outer side wall is filled with heat conducting adhesive for heat transfer; the peripheral outer sides of respective column cylinders are filled with at least three groups of solid liquid phase-change energy storage bodies respectively; the solid liquid phase-change energy storage bodies in different groups comprise solid liquid phase-change materials at different working temperature sections; when the temperatures of the lithium cells are increased, energy can be absorbed and stored to delay the rate of temperature increasing of the lithium cells; and when the temperatures of the lithium cells are lowered, the pre-stored heat can be released to delay the cooling speed of the lithium cells, so that the lithium cells can be maintained within the set working temperature range for a longer time.

Description

technical field [0001] The invention relates to a multi-type phase change heat balance system for electric vehicle lithium battery packs, which is used for all-weather thermal management of electric vehicle lithium battery cells. Background technique [0002] Electric vehicles use lithium battery packs as the power source to drive the car. The battery cells of lithium batteries are suitable for charging and discharging within the temperature range of 20-40°C in order to exert the maximum performance of lithium batteries. However, the lithium battery will generate heat during charging and discharging, which will cause the temperature of the lithium battery to exceed the above-mentioned suitable temperature range, thus affecting the performance and safety of the lithium battery. The power is far less than the set value, which affects the cruising range of the electric vehicle. In the prior art, some heat conduction devices are used to dissipate the heat of the lithium battery...

AI Technical Summary

Problems solved by technology

However, the thermal conductivity of solid-solid or solid-liquid phase change materials is not high, and their heat storage performance is very good. Therefore, these materials are not suitable for use as heat conduction devices, which is not conducive to the rapid conduction of lithium battery heat.

[0003] On the other hand, when the temperature of the lithium battery cell is lower than the above-mentioned suitable temperature range, its charging and discharging performance will also be significantly reduced, especially when the operating environment of the electric vehicle is a cold area below 0°C, the charging and discharging performance of the electric vehicle will be reduced. A decrease of more than 35% will adversely affect the cruising range of electric vehicles

In addition, when electric vehicles are charged in a low temperature environment, lithium batteries have the risk of explosion

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