Lithium ion battery pack capable of realizing uniform heat dissipation

Abstract

The invention discloses a lithium ion battery pack capable of realizing uniform heat dissipation. The lithium ion battery pack comprises a shell and a plurality of battery cells, a heat exchanger is arranged in the lithium ion battery pack, electric insulation heat conduction bags holding cooling liquid are arranged between adjacent battery cells, an air inlet, an air outlet, a cooling liquid inlet and a cooling liquid outlet are formed in the heat exchanger, the air inlet is connected with an air pump that can pump air, the cooling liquid outlet is connected with a liquid pump, an output end of the liquid pump conveys cooling liquid into the electric insulation heat conduction bags through liquid conveying pipelines, outlets are formed in the electric insulation heat conduction bags, and the outlets are connected with the cooling liquid inlet through the liquid conveying pipelines to form a cooling liquid loop. As the cooling liquid is not in direct contact with the battery cells in the whole process, the defects of cooling liquid corrosion and short circuit are avoided, the lithium ion battery pack disclosed by the invention adopts a uniform heat dissipation mode, thereby being unlikely to generate liquid leakage, the installation and subsequent maintenance are convenient, and compared with the existing liquid cooling manner, the cost is greatly reduced, and the uniform heat dissipation effect is better.

Description

technical field [0001] The invention relates to the field of electric vehicle batteries, in particular to a lithium-ion battery pack capable of uniform heat dissipation. Background technique [0002] Since the lithium-ion battery pack is greatly affected by temperature, it is easy to decompose the battery electrolyte and cause premature aging of the battery. The existing lithium-ion battery pack usually needs to be forced to ventilate and dissipate heat to avoid heat accumulation. However, when the electric vehicle is just started or when climbing a slope, the battery pack will dissipate much more heat than during normal operation. It is often difficult for traditional cooling fans to dissipate the heat in a short time, which will cause The temperature of the battery cell rises rapidly. When the temperature of the cell reaches 45°C or higher, the cell will be in the state of rapid discharge, while the cell that has not reached this temperature is still in the state of normal...

AI Technical Summary

Problems solved by technology

However, when the electric vehicle is just started or when climbing a slope, the battery pack will dissipate much more heat than during normal operation. It is often difficult for traditional cooling fans to dissipate the heat in a short time, which will cause The temperature of the battery cell rises rapidly. When the temperature of the cell reaches 45°C or higher, the cell will be in the state of rapid discharge, while the cell that has not reached this temperature is still in the state of normal discharge. After several times, the cell will be in the state of rapid discharge. The service life and performance of the core will be greatly reduced, and the performance of the battery pack will not meet the initial design requirements and goals

[0003] Therefore, the air-cooled method cannot achieve the purpose of evenly dissipating heat from the battery pack. At the same time, while ventilating the battery pack, it is easy to bring dust and other debris into the battery pack to pollute the battery cells, resulting in a state of charge and discharge of the battery pack. Poor, when it is serious, it is easy to cause a local small-scale short circuit in the battery pack, which will further aggravate the uneven heat release in the battery pack and greatly reduce the battery performance

[0004] In the prior art, there is another method of circulating heat dissipation for the battery pack by using oil. The general plan is to pass oil into the battery box to effectively dissipate heat for the battery pack through the oil. Since the thermal conductivity of the liquid needs to be Higher than gas, rapid and uniform heat dissipation can be achieved through liquid cooling, which makes up for the lack of air cooling, but the direct contact between the battery pack and the oil is not conducive to the long-term use and safety of the battery pack, and it is easy to corrode and damage the seal of the battery pack In addition, the liquid cooling method has higher requirements on the structure and materials of the battery box and the battery pack, and has strict restrictions on the sealing performance of the battery box, resulting in the liquid cooling method being more costly than air cooling It is much higher, therefore, there are more deficiencies in the way of liquid cooling

Images