Silicon monoxide composite cathode material for lithium ion battery, and preparation method thereof

Abstract

The invention discloses a silicon monoxide composite cathode material for a lithium ion battery, and a preparation method of the silicon monoxide composite cathode material, aiming at improving the cycle performance. The composite cathode material comprises the components by mass percent: 10-30% of composite particle material and 70-90% of natural graphite or artificial graphite, wherein the composite particle material is silicon monoxide covered by a carbon nano tube and an amorphous carbon coating layer. The method comprises the following steps of: forming the carbon nano tube and the amorphous carbon coating layer on the surface of silicon monoxide to obtain composite particles, and mixing the composite particles with the graphite. Compared with the prior art, the preparation method enables cracking carbon to be covered on the surfaces of silicon monoxide particles, so that the volume effect of the silicon monoxide particles can be effectively inhibited in the charge-discharge process of a battery, the cycle performance is good, the specific capacity is more than 500mAh / g, and the capacity retention ratio is more than 85% after the circulation is carried out for 100 times; and the preparation method is simple in preparation technology, low in raw material cost and suitable for the cathode material for the high-capacity lithium ion battery.

Description

technical field [0001] The invention relates to a battery material and a preparation method thereof, in particular to a lithium ion battery negative electrode material and a preparation method thereof. Background technique [0002] With the increasing shortage of traditional energy materials such as coal and oil in the world, people are working on developing new energy sources that can replace traditional fossil energy sources. Lithium-ion batteries have high voltage, high energy density, no memory effect, long life, and are environmentally friendly. Pollution, small self-discharge and other advantages, and become the preferred power supply equipment for various portable electronic products. [0003] At present, the anode materials of lithium-ion batteries are mainly carbon-based materials, including natural graphite and artificial graphite, but their low theoretical capacity (372mAh / g) no longer meets the development requirements of lithium-ion batteries for high capacity a...

AI Technical Summary

Problems solved by technology

The silicon monoxide negative electrode material prepared by the above prior art method generally pursues high capacity, generally at 1000mAh / g, but the cycle performance is poor, and the capacity retention rate after 100 cycles of cycle is only 50% to 60% of the original, realizing industrialization still have great difficulty

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