Formation method for power lithium ion battery

Abstract

The invention discloses a formation method for a power lithium ion battery. With the method, lithium titanate is adopted as a cathode, lithium iron phosphate is adopted as an anode, and a sealed formation method is adopted. The method comprises the following concrete steps: adopting a three-stage charging treatment to carry out constant current charging for a battery; then carrying out constant voltage charging for the battery; placing the battery in a liquid injecting glove box after the voltage of the battery is the cut-off voltage during the constant voltage charging; opening a liquid injecting port, vacuum pumping the gas generated by the battery, and then sealing the liquid injection port. With the method provided by embodiments of the present invention, a compact and stable SEI film can be effectively formed on the cathode surface; the sealed formation method is adopted during the formation process, such that the influence on the battery performance due to the reaction generated between the moisture and the electrolyte is avoided, wherein the reaction is generated due to water absorbing inside the battery; after the voltage of the battery is the cut-off voltage during the constant voltage charging, the gas generated from the battery is removed through vacuum pumping, then the liquid injecting port is sealed, such that the environment inside the battery shell is effectively improved, the battery bulging during the using process is avoided, the performance degradation of the battery is delayed, the electrical property and the safety performance of the battery are improved.

Description

technical field [0001] The invention relates to a battery formation method, in particular to a power lithium ion battery formation method. The power lithium ion battery uses lithium titanate as a negative electrode and lithium iron phosphate as a positive electrode. Background technique [0002] Lithium titanate (Li 4 Ti 5 o 12 ) is a "zero-strain" electrode material with good cycle performance, a good charge-discharge platform and high-current charge-discharge performance, and also has good overcharge resistance, thermal stability and safety performance. New materials for ion power batteries. [0003] For example, the Chinese invention with the publication number CN101740816A discloses a method for the formation of a lithium-ion secondary battery, wherein the charging process includes charging with a large current and constant current to the charging cut-off voltage and constant voltage charging to the cut-off current, and then constant voltage charging to the cut-off cu...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the problem that the SEI film formed by the method described in the above prior art is uneven and unstable, thereby affecting the cycle life of the battery, and the method of o...