Power battery device of electric vehicle

Abstract

The invention discloses a power battery device of an electric vehicle. The power battery device comprises each battery module which is encapsulated between a module upper cover and a module bottom plate, and a heating film which is used for heating each battery module, wherein grooves are formed in the inner surface of the module bottom plate for dividing the inner surface of the module bottom plate into a supporting surface and a groove surface; the battery modules are supported on the supporting surface; the heating film is pasted on the bottom surfaces of the grooves; the thickness of the heating film is smaller than the depth of the corresponding grooves so as to form heating gaps between the heating film and the battery modules. By virtue of the heating gaps, the heating film of the power battery device is a heating structure for heating of the battery modules, so that on one hand, a problem that temperatures of the battery modules are too high due to direct contact of the heating film and the battery modules can be avoided so as to improve the heating safety, and on the other hand, the heating uniformity can be improved, so that a temperature gradient among different points of the battery modules can be reduced and the service lives of the battery modules can be prolonged.

Description

technical field [0001] The invention relates to a power battery device of an electric vehicle, in particular to a heating structure design of the power battery device. Background technique [0002] As the power source of electric vehicles, the cost of power battery devices has accounted for one-third of the cost of the whole vehicle. Therefore, the price of power battery devices has become one of the bottlenecks restricting the development of electric vehicles. One reason for the high cost of the power battery device is that the power battery device needs to be equipped with a heating structure for heating the battery module in a low temperature environment, so as to ensure that the battery module can be used normally in a low temperature environment. The existing heating structure of the power battery device is divided into heating wire heating, heating film heating and liquid heating. The heating wire heating mainly uses the fan to drive the air flow on the surface of the ...

AI Technical Summary

Problems solved by technology

One reason for the high cost of the power battery device is that the power battery device needs to be equipped with a heating structure that heats the battery module in a low temperature environment to ensure that the battery module can be used normally in a low temperature environment

The existing heating structure of the power battery device is divided into heating wire heating, heating film heating and liquid heating. The heating wire heating mainly uses the fan to drive the air flow on the surface of the heating wire to heat the battery module. The disadvantage of heating wire heating is reflected in the efficiency Low temperature and large temperature difference. Because fans need to be installed, the space requirements for the power battery device are relatively high, and the cost is also high. The heating of the heating film mainly uses heat conduction to heat the battery module. The advantage of heating the heating film is heating Uniformity, high efficiency, easy installation, low space requirements and low cost; liquid heating needs to use a heating device to heat the liquid first, and then use a power device such as a pump to make the liquid flow through the battery module to achieve heat transfer through heat conduction. For battery module heating, liquid heating has the advantage of high heating efficiency, but its disadvantages are high heating cost and poor system stability

[0003] In view of the above-mentioned advantages of heating film heating, in order to control the cost of power battery devices, heating film heating has become the choice of more designers. However, the heating structure realized by using heating film is basically to paste the heating film directly on the side of the battery module. On the wall, the defects of this kind of heating structure are: the direct contact between the heating film and the battery module will cause the temperature of the battery module to be too high and a large temperature gradient will be generated between each battery module. If the method of reducing the power density of the heating film is used to solve the above problems, the heating time will be too long, which will affect the performance of the electric vehicle

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