Method for improving multiplication cycle performance of lithium battery

Abstract

The invention discloses a method for improving the multiplication cycle performance of a lithium battery. The method comprises the following steps: step 1, injecting an electrolyte into the battery, standing the battery for a first preset time, and standing the battery for a second preset time at a first preset temperature, so that the internal temperature of the battery is consistent with the first preset temperature; step 2, after the battery is charged with first preset current to reach a first preset charged state, standing the battery for a third preset time at a second preset temperature, so that the internal temperature of the battery is consistent with the second preset temperature; step 3, charging the battery with second preset current to reach a second preset charged state; step 4, charging the battery with third preset current to reach a third preset charged state, and standing the battery for a fourth preset time at a third preset temperature, so that the internal temperature of the battery is consistent with the third preset temperature; and step 5, finally, performing multiple times of cyclic discharge by adopting fourth preset current at a fourth preset temperature to sufficiently activate the battery.

Description

[0001] 【Technical field】 [0002] The invention relates to the technical field of electric vehicle batteries, in particular to a method for improving the rate cycle performance of lithium batteries. [0003] 【Background technique】 [0004] Lithium-ion battery is a kind of energy storage battery that has been developed rapidly in recent years. Compared with other existing rechargeable secondary batteries, lithium-ion battery has high voltage, high specific energy, long charge and discharge life, no memory effect, and no pollution. It has been widely used in various electronic equipment, electric vehicles, electric bicycles and electric tools, and is a hot spot in the development of new energy. Formation is an important process in the manufacturing process of lithium-ion batteries. Its purpose is to activate the active materials on the surface of the internal electrodes of the battery on the one hand, and to form a layer of SEI (Solid Electrolyte Interface) film on the surface of...

AI Technical Summary

Problems solved by technology

Then, during the first charging process, there are some irreversible lithium intercalation reaction sites that cannot be fully consumed, so that a stable SEI film cannot be formed on the surface of the negative active material of the lithium-ion battery. Decays fast and takes more production time in the process

However, although the method of forming and charging with a large current alone can improve production efficiency, it makes the SEI film formation unstable, and the structure is easy to collapse, resulting in the co-embedding of electrolyte solvent molecules, which seriously affects the electrical performance of lithium batteries.

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