Preparation method of vulcanized conducting polymer composite anode for lithium ion battery

Abstract

The invention discloses a preparation method of a vulcanized conducting polymer composite anode for a lithium ion battery. In the method, a conducting polymer of polyaniline-pyrrole is used as a main substrate, sulphur is a main active substance, the simple substance of sulphur and the conducting polymer of polyaniline-pyrrole are compounded at different temperatures by using a co-hot method, and the granularity of the powder can reach a micron size, a submicron size and a nanometer size. The anode material prepared by the method has the initial discharge capacity of 1144 mAh / g under the conditions that the constant current density is 0.2 mA / cm<2>, the charging voltage upper limit is 3.0 V, and the charging voltage lower limit is 1.5 V, and the specific capacity still maintains 929 mAh / g after 20 times of circulation. It can be seen from a CV curve that the vulcanized conducting polymer composite anode material at 250 DEG C has high capacity reversibility and favorable cyclical stability.

Description

technical field [0001] The invention relates to the field of lithium-ion batteries, in particular to a method for preparing a vulcanized conductive polymer composite cathode material for lithium-ion batteries. Background technique [0002] In recent decades, with the rapid development of the battery industry, the specific energy of secondary batteries is also increasing, from 30 to 40Wh / kg for lead-acid batteries, 40 to 50Wh / kg for nickel-cadmium batteries, and 60 for nickel-hydrogen batteries. ~80Wh / kg, developed to commercial lithium-ion batteries in the 1990s reached 100~130Wh / kg, and has now reached 200Wh / kg. Lithium secondary battery consists of three parts: positive electrode, negative electrode and electrolyte. The battery chemical system determines the electrochemical reaction of the battery, thereby determining the theoretical voltage, theoretical specific capacity and theoretical specific energy of the battery. Lithium-ion batteries use carbon as the negative elect...

AI Technical Summary

Problems solved by technology

[0003] The electronic conductivity of the element S is extremely poor. When used as a positive electrode material, the utilization rate of the active material S is not high, the reversibility is poor, and the capacity continues to decline; and with the progress of the electrode reaction, Li 2 The S passivation layer will react with the S dissolved in the electrolyte to generate Li 2 S 2 , which leads to the dissociation of the passivation layer and the formation of soluble polysulfides, which ultimately affects the stability of the electrolyte.

Images