Method for determining infiltration state of lithium ion battery electrolyte

Abstract

The invention discloses a method for determining infiltration state of a lithium ion battery electrolyte. The method comprises the steps of: (1) preparing a colored impregnating compound, adding the colored impregnating compound into an electrolyte, and performing uniform mixing to obtain the colored electrolyte; and (2) injecting the colored electrolyte into a battery to dismount the battery while completing primary electrolyte injection, formation and secondary electrolyte injection, determining the infiltration state of the electrolyte by determining whether the color region distribution ona diaphragm and a pole piece is uniform or not to regulate the primary electrolyte injection amount, the second electrolyte injection amount and the formation process. Compared to a traditional method, the method has the advantages that the electrolyte infiltration state is confirmed by distinguishing the color region distribution on the diaphragm and the pole piece, and the impregnating compoundis not easy to volatilize, so that the electrolyte can be observed carefully for a long time. The method can conveniently, quickly and visually distinguish the electrolyte infiltration state, improves the consistency in the production process of the battery, and ensures the cycle and rate capability of the battery.

Description

technical field [0001] The invention belongs to the research field of lithium-ion batteries, and in particular relates to a method for judging the infiltration state of an electrolyte solution of a lithium-ion battery. Background technique [0002] Lithium-ion power battery is an important part of electric vehicles, and its performance directly affects the normal function of electric vehicles. Because of its popularization and use, its battery consistency and cycle performance are problems that need to be solved urgently. Among them, the formation of the battery is the process of charging the battery for the first time, which directly affects the quality of the formation of the solid electrolyte film of the battery, and directly affects the cycle performance and consistency of the battery in the later stage. The most important thing in the formation is that the electrolyte needs to have good infiltration in the pole piece and the separator, and there is a surplus in order t...

AI Technical Summary

Problems solved by technology

[0003] However, the current domestic battery production process has a single method to observe the infiltration state of the electrolyte in the battery. Simply disassemble the battery to observe the remaining electrolyte volume and the state of the diaphragm, but because the organic solvent in the electrolyte is volatile, disassemble to observe the infiltration state , it is not possible to observe carefully

Add more electrolyte to ensure infiltration, which will easily lead to waste of electrolyte and increase battery production cost

If the amount of electrolyte is reduced, it is easy to have a negative impact on battery performance

[0004] Therefore, there are constraints on the formulation of processes such as chemical formation, primary liquid injection, secondary liquid injection, and aging in battery production, which affects the consistency of battery batches