Liquid injection method and device for lithium-ion power battery

Abstract

The invention discloses a liquid injection method and device for a lithium-ion power battery, and provides a rubber plug for liquid injection. The rubber plug for liquid injection has a central through hole, the lower part of which is matched with the liquid injection hole of the battery, and the upper part is with the injection hole. The funnel-shaped interface matched with the liquid nozzle; before one injection, install the rubber plug for liquid injection on the liquid injection hole; the liquid injection nozzle of the liquid injection machine is directly matched with the upper part of the rubber plug for liquid injection, so that the liquid injection nozzle It is sealed with the rubber plug for liquid injection for liquid injection; a steel nail is provided, the steel nail is in interference fit with the central through hole of the rubber plug for liquid injection, and the top of the steel nail is provided with an enlarged head; After the liquid is completed, insert the steel nail into the central through hole to seal it and set it aside, then pull out the steel nail and proceed to chemical formation, then insert the steel nail to seal the central through hole and set aside, then pull out the steel nail for the second injection, after the second injection is completed Pull out the rubber plug for liquid injection, install and weld the sealing rubber nail, thereby realizing the liquid injection of the battery. The invention solves the problems caused by the leakage of the electrolyte and the dirty liquid injection nozzle during the liquid injection process, and is convenient to operate, simplifies the technical process, and saves the production cost.

Description

technical field [0001] The invention relates to a preparation method of a lithium-ion power battery, in particular to a method for primary liquid injection and secondary liquid injection of a lithium-ion power battery, and a device used in the method. Background technique [0002] During the preparation process of the lithium-ion power battery, the electrolyte needs to be injected into the battery according to the required amount through the reserved liquid injection hole. The liquid injection process usually includes primary liquid injection and secondary liquid injection. After the primary liquid injection, chemical formation is required, that is, through a high-temperature aging room, the electrolyte is infiltrated into the pole piece and diaphragm, and participates in chemical reactions to realize chemical energy and Transformation of electrical energy; the secondary injection is the process of supplementing the electrolyte after formation. Due to the gas generated duri...

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Problems solved by technology

[0003] In the above process, there are the following problems: (1) The electrolyte will drip around the liquid injection hole and spread to the battery during liquid injection, resulting in the need to clean the liquid injection port immediately after the first liquid injection and the second liquid injection. The welding position of the liquid injection port needs to be cleaned again before the sealing nail is welded

If it is manually wiped, solid waste will be generated during the cleaning process; if it is cleaned by laser equipment, exhaust gas and smoke will be generated during the cleaning process

However, these three cleaning processes are difficult to complete, which has always been a manufacturing problem in the industry

(2) When injecting liquid, it is necessary to install a sealing structure on the liquid injection nozzle, and realize the seal between the pressure of the liquid injection nozzle and the liquid injection hole. During the liquid injection process, the sealing structure on the liquid injection nozzle will be contaminated with electrolyte. If the liquid injection nozzle is not cleaned in a circular manner during the liquid injection process, the pollution of the liquid injection port will be more serious during the liquid injection process, and the three cleaning processes after liquid injection and before sealing nail welding will be more difficult

The cleaning of the injection nozzle has always been a difficult problem in the industry, the cleaning effect is limited, and the cleaning process will consume solvents and generate cleaning waste

(3) The shelving process before and after formation requires temporary sealing of the battery liquid injection port with a sealing plug. It is difficult to assemble and disassemble), so the sealing effect is limited, and the environment where the battery is placed needs to be equipped with a dehumidifier to control the moisture in the air

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