Method for manufacturing high-rate and high-temperature lithium titanate polymer lithium ion battery

Abstract

The invention discloses a method for manufacturing a high-rate and high-temperature lithium titanate polymer lithium ion battery. The method comprises the following three steps: (1) increasing the number of cell tabs in a manner of leading out the tabs from two ends; (2) doping high-conductivity ECP-600JD into common conductive carbon SP; and (3) adding a certain content of VC to an electrolyte system. Compared with the prior art, according to the method for manufacturing the high-rate and high-temperature lithium titanate polymer lithium ion battery, the dual-tab structure is used, so that the problems of current concentration, large battery polarization, over-high calorific value of the battery and poor high-temperature performance are solved; the conductivity of the electrolyte and the conductivity of the battery are improved by coordination of the high-conductivity ECP-600JD-doped conductive carbon and the VC; and the lithium ion battery also has an obvious improvement effect on flatulence by coordination of the VC and PC in the electrolyte, so that the problems such as poor high-temperature performance, low rate and flatulence of the lithium titanate battery in application are solved through a series of methods.

Description

【Technical field】 [0001] The invention relates to the field of lithium batteries, in particular to a method for manufacturing a high-rate high-temperature lithium titanate polymer lithium ion battery. 【Background technique】 [0002] Commercial lithium-ion battery negative electrode materials are still mainly graphite and amorphous carbon materials. Since the potential of the carbon electrode after lithium intercalation is very close to that of metal lithium, when the battery is overcharged, metal lithium is easy to precipitate on the surface of the carbon electrode. It reacts with the electrolyte to produce a flammable gas mixture, thus causing a great safety hazard to the battery, especially the power battery. At the same time, the graphite electrode also has the problem of co-intercalation of the electrolyte, which will also affect the cycle stability of the electrode. Therefore, it is necessary to find new anode materials that can intercalate lithium at a slightly positi...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, lithium titanate as the negative electrode is usually combined with a ternary or lithium manganate positive electrode to make a high-rate battery, but pure lithium titanate has a low conductivity of only 10 -9 S / cm, the surface of the particles is relatively smooth, and the ability to adsorb electrolyte is poor, which is not conducive to the performance of the battery rate performance. At the same time, because the electrode potential of lithium iron phosphate itself is as high as 1.55V, it is difficult to form an effective SEI film during the first charging process, resulting in subsequent charging. It is easy to produce gas during charging and discharging, especially the high temperature performance is poor, and it is easy to bloat

Therefore, how to solve the shortcomings of lithium titanate batteries such as low discharge resolution, easy flatulence, and poor high-temperature performance has become a common technical breakthrough point in the industry.

[0004] In view of the above disadvantages, it is necessary to provide a high-rate high-temperature lithium titanate polymer lithium-ion battery manufacturing method to overcome the defects of the above-mentioned lithium titanate battery such as low discharge rate, easy flatulence, and poor high-temperature performance.

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