Formation aging method for inhibiting gas expansion of lithium titanate battery

Abstract

The invention discloses a formation aging method for inhibiting the gas expansion of a lithium titanate battery. The formation aging method is used for solving the gas expansion problem of the lithiumtitanate battery generated in the using process. The method comprises three steps of previous standing, formation and aging. In the formation step, the lithium titanate battery after previous standing adopts a constant-current charging manner of first high current and then low current, the battery is charged to a cut-off voltage higher than a working voltage platform and is discharged to a half-charge state after standing. The formation aging method is based on a lithium titanate battery gas production mechanism; the charging manner of first high current and then small current is adopted in the formation process, the lithium titanate material is promoted to form an SEI film in a forced manner under high potential; the battery is discharged in the half-charge state after formation standing, and the battery is placed in a low temperature environment to promote further growth and densification of the SEI film formed in the formation process. The dense SEI film is formed on the surface ofthe anode lithium titanate material, so that the chemical reaction of an electrolyte is prevented at the position of the anode; and the purposes of inhibiting gas production and reducing expansion are reached.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a formation and aging method for suppressing flatulence of lithium titanate batteries. Background technique [0002] Lithium titanate material can be used as the negative electrode material of the battery. Lithium titanate battery can achieve a cycle life of tens of thousands of cycles and a rate charge and discharge performance higher than 30C, and has excellent safety performance. It is comparable in terms of cycle, rate and safety. Compared with traditional graphite anode materials, it has huge advantages; however, lithium titanate batteries face the problem of battery flatulence during the commercialization process, and battery flatulence will cause bubbles between the positive and negative electrodes inside the battery, causing + Migration is difficult, and dead lithium areas appear, resulting in reduced capacity and worsened cycle performance. Although there is s...

AI Technical Summary

Problems solved by technology

In the actual production process of batteries with lithium titanate as the negative electrode, the introduction of moisture needs to be strictly controlled in theory. However, for battery manufacturers, the humidity in other sections except the liquid injection room is only controlled at about 20%. , if the humidity needs to be further reduced, the production cost will increase sharply

[0004] At present, most of the invention patents on the use of lithium titanate battery as the negative electrode material to solve the problem of battery cycle flatulence are focused on the development of equipment for opening negative pressure formation. For the patents on the formation and aging methods used by the battery itself, most of them are carried out by using small currents. Multi-stage floating charging is the main focus. On the one hand, similar invention patents have higher requirements on process equipment; on the other hand, the battery formation process takes a long time, which cannot adapt to the industrialization of lithium titanate batteries.

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