Two-phase immersed battery liquid cooling device for super fast charging of lithium battery and cooling system of two-phase immersed battery liquid cooling device

Abstract

The invention belongs to the technical field of power batteries, and provides a two-phase immersed battery liquid cooling device for super fast charging of a lithium battery and a cooling system of the two-phase immersed battery liquid cooling device. According to the device, the electric heating film is adopted to preheat the lithium battery before fast charging, and then the phase change latent heat of the fluorinated liquid is utilized to take away heat generated in the fast charging process of the battery, so that the temperature rise of the battery in the fast charging process can be effectively limited at a relatively high initial temperature; and the temperature of the battery can be accurately controlled to be close to the boiling point of the fluorinated liquid, so that the thermal safety of the lithium battery in the fast charging process is greatly improved. And after the fast charging is finished, the high-temperature fluorination liquid in the battery box is pumped into the liquid storage tank by using the electromagnetic pump, and normal-temperature liquid is injected into the battery box, so that the temperature of the lithium battery is quickly reduced to the room temperature level after the fast charging is finished, the growth of SEI in the battery during the subsequent discharging or storage period is inhibited, and the cycle life of the lithium ion battery is greatly prolonged.

Description

technical field [0001] The invention belongs to the technical field of power batteries, in particular to a two-phase submerged battery liquid cooling device for fast charging of lithium batteries and a cooling system thereof. Background technique [0002] In recent years, in order to alleviate the impact of energy shortage and environmental pollution, new energy vehicles with lithium-ion batteries as the main power source have received widespread attention around the world, and the global automotive industry has gradually transformed from traditional fuel vehicles to electric vehicles. However, compared with traditional fuel vehicles, problems such as long charging time and mileage anxiety have become the primary bottleneck restricting the development of electric vehicles. At present, reducing the charging time of electric vehicles usually adopts increasing the charging speed of electric vehicles and shortening the time required for charging. For example, the Nissan Leaf's ...

AI Technical Summary

Problems solved by technology

However, direct refrigerant cooling requires high air tightness of the system. At the same time, the heat dissipation uniformity of the direct refrigerant cooling system is poor, resulting in a large temperature difference between different cells in the battery pack.

Under fast charging conditions, a large temperature difference will lead to inconsistent SOC states between different battery cells, which in turn will cause safety hazards such as overcharge and overdischarge.

It can be seen that the current common commercial battery thermal management solutions are difficult to effectively dissipate the heat generated by the battery pack during the fast charging process.

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