Formation method for lithium ion battery

Abstract

The invention discloses a formation method for a lithium ion battery. Over-charging is avoided, and the low capacity ratio of the battery can be lowered. In an environment of -20 to 45 DEG C, the method comprises the following steps of: performing 0.05 to 0.2-time constant current charging on the lithium ion battery for 3 to 5 hours, and setting cutoff voltage to be 3.0 to 4.0 volts, wherein a gas can be generated in the battery after the charging is finished; disassembling the battery, and performing a vacuumizing packaging procedure to exhaust the gas generated by the internal formation process of the battery; performing 0.2 to 30-time constant current charging on the lithium ion battery, and setting the cutoff voltage to be 3.0 to 4.0 volts; and performing constant voltage charging on the lithium ion battery, and setting cutoff current to be 0.001 to 0.02 time. The method has the advantages that local over-charging is prevented, the low capacity ratio of the battery can be remarkably lowered, and the consistency of the battery can be improved.

Description

technical field [0001] The invention relates to a lithium ion battery formation method. Background technique [0002] At present, the formation method of lithium-ion batteries is as follows: the battery soaked by liquid injection is charged with a small current and a constant current of 0.01 to 0.04 times, and the charging time is 0.5 to 5 hours, and then charged with a large current and a constant current of 0.05 to 2 times. After the voltage is 3.65-4.5 volts, let the battery enter the constant voltage charging stage. The voltage is kept between 3.65-4.5 volts. When the charging current is reduced to 0.001-0.02 times, stop charging and the formation is over. The battery using the above-mentioned formation method has serious formation and gas production, and is prone to partial overcharging, resulting in electrolyte decomposition and defects such as mottling and lithium precipitation on the surface of the negative electrode sheet, which seriously affects the capacity of the...

AI Technical Summary

Problems solved by technology

The battery using the above-mentioned formation method has severe formation and gas production, and is prone to partial overcharging, resulting in electrolyte decomposition and defects such as mottling and lithium precipitation on the surface of the negative electrode sheet, which seriously affects the capacity of the battery and the consistency between batteries.

At the same time, the above-mentioned formation method also has the problems of long formation time and large investment in equipment and labor.