Degassing device and method for soft package lithium ion battery

Abstract

The invention provides a degassing device of a soft package lithium ion battery. The device comprises a bottom plate and an air suction pipe; a groove capable of accommodating a battery cell is formedin the bottom plate; one end of the bottom plate is rotatably connected with a cover plate for extruding an air bag; the battery cell is located in the groove; a needle for piercing the battery cellair bag is arranged at one end, close to the battery cell, of the air suction pipe, and the other end of the air suction pipe is connected with external vacuum equipment. The invention further comprises a method for degassing the soft package lithium ion battery by using the degassing device. According to the degassing device and method provided by the invention, the battery cell does not need tobe equipped with a relatively long air bag; the aluminum-plastic film material is saved; the manufacturing universality of different models and different systems of batteries is improved; the production cost of the battery is reduced; the pre-charged produced gas can be timely and effectively removed; the integrity of the SEI film in the pre-charging process is ensured; and the performance of thebattery cell is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a degassing device and method for a soft-pack lithium-ion battery. Background technique [0002] For lithium-ion batteries, when pre-charging is the first charge, while SEI film is formed on the surface of the negative electrode, a large amount of gas products will occur in side reactions. For soft-pack lithium-ion batteries, the usual solution is to use a larger The aluminum-plastic film-encapsulated battery cell of the size is large, and there is a long enough air bag at the side sealing edge to collect the gas generated during the pre-charging process. The disadvantage of this method is that with the development of batteries of different systems and the selection of different electrolyte formulas, the gas production of the batteries during pre-charging is different, and the air bag usually needs to reserve a longer air bag according to the design of t...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that with the development of batteries of different systems and the selection of different electrolyte formulas, the gas production of the batteries during pre-charging is different, and the air bag usually needs to reserve a longer air bag according to the design of the actual battery system. To ensure the full storage of the pre-filled body, it will cause a great waste of aluminum plastic film, which is the production material of the battery cell

In addition, the gas generated during the pre-charging process will generate a relatively high pressure when left in the air bag. If the air bag is small, the gas will return to the main interface of the battery under high pressure, forming a gap between the interfaces of the battery. Bubbles, charge and discharge in this state, the integrity of the SEI film is destroyed, affecting the performance of the cell

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