High-capacity negative electrode material, preparation method and lithium ion battery

Abstract

A high-capacity negative electrode comprises a negative electrode current collecting foil and a negative electrode material; the negative electrode material comprises a negative electrode active material, a conductive agent and a binder; the negative electrode active material comprises an active carbon material, and nano spherical phosphorus particles are embedded in the active carbon material; and the conductive agent, the binder and the negative electrode active material are uniformly mixed and then coated on a negative electrode current collector. In the present invention, the activated carbon is combined with red phosphorus to effectively improve the conductivity of a phosphorus material; the nano spherical phosphorus particles are uniformly dispersed on the activated carbon, so that the contact area of an electrolyte is increased, more importantly, the structure of the material can be stabilized due to existence of P-C bonds, the volume expansion of the phosphorus material in thecharge-discharge cycle process is effectively relieved, and the cycle performance of the battery is ensured.

Description

technical field [0001] The invention relates to a lithium ion battery, in particular to a negative electrode material with high capacity, a preparation method and the lithium ion battery. Background technique [0002] In today's world, with the environmental pollution caused by the burning of fossil fuels and global warming becoming more and more serious, all countries are transforming the economic model based on fossil fuels to an economic model based on new energy, and developing renewable energy and clean energy. It is a major strategic task of my country's economic and social development. With the rapid development of society, there is an imminent demand for high-security and low-cost energy storage technology. Lithium-ion batteries are considered to be one of the most promising energy storage technologies to meet these demands, and have been successfully applied in portable electronic devices, plug-in hybrid electric vehicles, and pure electric vehicles, effectively red...

AI Technical Summary

Problems solved by technology

However, when the composite material was assembled into a battery for electrochemical testing, at a test current of 100 mA g -1 and a voltage range of 0.02 to 3 V, its first reversible discharge capacity was 680 mAh g -1 , after 15 cycles After cycling, the capacity tends to be stable, and after 100 cycles, the capacity fades to 600 mAh g-1, indicating that the material has a low reversible capacity

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