Gas medium based temperature-controlled and voltage-controlled lithium battery formation device

Abstract

The invention discloses a gas medium based temperature-controlled and voltage-controlled lithium battery formation device, which comprises a gas container, a sealing system, a gas supply system, a temperature and pressure control system and a power system. By using gas as a flowing medium, the temperature-controlled and voltage-controlled lithium battery formation device can avoid pollution and distortion of lithium batteries, has no risk of short circuit, and can ensure uniform pressure inside lithium batteries in the process of formation and improve the performance of lithium batteries. Because various non-corrosive gases can be used, the device has good convenience. In addition, the functions of electrochemical detection and package leak detection can be added during formation.

Description

technical field [0001] The invention relates to lithium battery formation equipment, more specifically to a gas medium temperature-controlled and pressure-controlled lithium battery formation device. Background technique [0002] Lithium battery formation refers to the process of charging and discharging the lithium battery after the lithium ion lithium battery is assembled. During this process, the lithium battery system will be activated, so the manufacturing process is an extremely important link. Through formation, a layer of solid electrolyte interface passivation layer, that is, SEI film, will be formed on the surface of the material of the lithium battery. [0003] The traditional formation process is to make the lithium battery form a film stably and fully under stable temperature and pressure through trickle charge and discharge. However, the SEI film formed by this method has a compact structure and small pores, so high-temperature aging is required to restructure...

AI Technical Summary

Problems solved by technology

[0005] 1. When the thickness of the electrode sheet on the lithium battery electrode group is uneven, the pressure applied by the clamp method will cause uneven force on the electrode group, and the force is mainly borne by the thick place, thus resulting in uneven distribution of the electrolyte in the lithium battery

Similarly, the uneven distribution of pressure and temperature makes the distance between the pole pieces inconsistent, and the electric field will appear uneven during formation, resulting in low capacity, uneven lithium intercalation and even lithium precipitation.

[0006] 2. The fixture method will cause a large area of ​​hard contact between the fixture and the lithium battery, resulting in surface pollution, uneven wrinkles and deformation of the lithium battery

[0007] 3. After heating, the cooling time of the fixture and lithium battery is longer

[0008] 4. The use of fixtures requires a large number of mechanical mechanisms to realize the handling and storage of lithium batteries. Therefore, some lithium batteries, such as soft bags that cannot be used on three or even four sides, will be restricted in large-scale production

However, the battery is in an open state during the formation process of this method, so the internal pressure of the battery is not in an isostatic state

The heating method mentioned in this method is to use a heating wire to heat the battery, which has low temperature control efficiency and uneven temperature distribution in the medium, and this method does not mention the temperature change of the medium and the temperature of the medium during the formation process. Pressure change using media

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