Modified soft carbon negative electrode material, lithium ion battery, negative electrode material and preparation method

Abstract

The invention discloses a modified soft carbon negative electrode material, a lithium ion battery, a negative electrode material and a preparation method. The preparation method of the modified soft carbon negative electrode material comprises the steps of sequentially carrying out activation treatment, washing, drying and heat treatment on a soft carbon carbonization precursor material, wherein the soft carbon carbonization precursor material is obtained by carbonizing a soft carbon precursor material at the temperature of 1250-1450 DEG C; the mass ratio of the soft carbon carbonization precursor material to an activating agent in the activating treatment process is 100: (3-15); the activating agent is an alkali metal-containing alkaline inorganic compound and / or chlorine-containing inorganic salt; and the temperature of the heat treatment is 500-700 DEG C. According to the modified soft carbon negative electrode material disclosed by the invention, the structure of the soft carbon isimproved, the amorphous degree of the soft carbon structure is improved, pore lithium storage sites of the soft carbon material are increased, lithium intercalation and deintercalation channels are increased, and the obtained modified soft carbon negative electrode material is high in initial reversible capacity, initial coulombic efficiency and capacity retention ratio after 100 cycles.

Description

technical field [0001] The invention specifically relates to a modified soft carbon negative electrode material, a lithium ion battery, a negative electrode material and a preparation method thereof. Background technique [0002] The negative electrode material is one of the four key materials of lithium-ion batteries, and its rate performance directly determines the fast charging performance of lithium-ion batteries. At present, commercialized graphite anode materials are difficult to meet the requirements of high-power, high-power, and The pace of high capacity and other demands. During the development of negative electrode materials, researchers found that soft carbon has an irregular turbostratic structure and a larger interlayer spacing than graphite, so it has high-rate charge-discharge performance and excellent low-temperature charge-discharge performance, and it is expected to be used in lithium-ion batteries. Solve the problem of its poor fast charging. However, ...

AI Technical Summary

Problems solved by technology

However, conventional soft carbon itself has common shortcomings: low reversible capacity (<250mAh / g) and low initial efficiency (<85%), so soft carbon materials have a lot of room for improvement in terms of capacity and efficiency

The first coulombic efficiency of the soft carbon negative electrode material is low, and the activator used in the preparation process of the patented soft carbon negative electrode material is a relatively expensive and active lithium-containing compound or a highly corrosive acidic compound or organic Compounds are more dangerous, the preparation conditions are too harsh, and the requirements for equipment are extremely high

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