Vacuum filling device of cylindrical lithium battery

Abstract

The invention discloses a vacuum filling device of a cylindrical lithium battery. A filling cup is fixed above a cover; a filling funnel is communicated with the filling cup; a filling valve is arranged in the filling cup; the cover is covered on a working platform to form a closed filling chamber; the upper end of a lithium battery to be filled is extended into the closed filling chamber; a filling needle assembly is arranged below the filling cup; the needle head is extended into the lithium battery to be filled; and the cover is provided with a vacuum pumping device. The vacuum filling device has the following advantages: when the vacuum pumping device is started, the air in the filling chamber is pumped out, so that the filling chamber forms a negative air pressure state; the filling valve is opened, so that part of electrolyte smoothly flows into the lithium battery to be filled through the filling needle; at this time, since the inside of the filling chamber is in a vacuum state, the electrolyte is floated on the coiled section of the lithium battery to be filled; the vacuum pumping device is switched to release a right amount of nitrogen gas into the filling chamber, so that air pressure difference exists between the upper and lower parts of the coiled section of the lithium battery; and under the effect of the air pressure difference, the electrolyte is sufficiently absorbed by the coiled section inside the lithium battery.

Description

technical field [0001] The invention relates to a battery liquid injection device, in particular to a vacuum liquid injection device for a cylindrical lithium battery. Background technique [0002] Electrolyte is one of the four key materials of lithium batteries, known as the "blood" of lithium batteries. The electrolyte, as the discharge medium of the lithium battery, provides ion conduction for the normal operation of the positive and negative electrodes. Therefore, in the process of lithium battery processing, the precise control of the liquid injection link is particularly critical. Whether it is the control accuracy of the liquid injection volume, the amount of battery liquid retention, the quality of the liquid absorption of the coiled product, and the level of ambient oxygen concentration will directly affect the discharge performance of the final product. [0003] Among them, whether the liquid absorption of the coiled product is uniform and sufficient is the most...

AI Technical Summary

Problems solved by technology

Once the coiled product cannot absorb liquid evenly, it may cause the electrolyte to float up. In the slightest, the battery capacity will decrease, the discharge capacity will decrease, and in severe cases, the battery shell will bulge or even the battery will leak.

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