Tin-carbon composite material for lithium secondary battery negative electrode and preparation method thereof

Abstract

The invention relates to a tin-carbon composite material for a lithium secondary battery negative electrode. The tin-carbon composite material is in a three-dimensional porous structure which is formed by uniformly dispersing the tin nano particles with ultrasmall granularity and embedding the tin nano particles into a three-dimensional porous carbon carrier material. The preparation method comprises the following steps of: utilizing a high-temperature pyrolysis tin compound, and uniformly dispersing and embedding the tin nano particles with ultrasmall granularity into the three-dimensional porous carbon carrier material. The high specific capacity characteristic of the tin can be maintained, the volume expansion of an electrode can be effectively controlled, the agglomeration phenomenon of the particles can be prevented, and the cycling stability can be improved; and the tin-carbon composite material can be used for preparing a lithium-ion battery. The tin-carbon composite material and the preparation method have the advantages that the ultrasmall granularity of the composite material and the three-dimensional porous structure favors the fast transmission of the ions, so that the power density of the lithium secondary battery negative material can be improved, and the cycling stability and magnification performance are good; and the preparation process is easy to control and simple to operate, the industrialized mass production is convenient to realize, and the tin-carbon composite material is expected to be applied to the next generation of high-energy high-power environment-friendly storage battery.

Description

technical field [0001] The invention relates to a tin-carbon composite material and a preparation method and application thereof, in particular to a tin-carbon composite material used for a negative electrode of a lithium secondary battery and a preparation method thereof. Background technique [0002] With the urgent demand for electric energy storage in power sources such as electric vehicles, lithium-ion batteries are increasingly being used due to their high energy and power density. At present, the negative electrode material of commercialized lithium-ion batteries is graphite, and its low theoretical capacity (372 mAh / g) cannot satisfy people's pursuit of high energy and high power density, which requires people to develop lithium-ion batteries with high capacity and high cycle stability. A new type of negative electrode material with high performance and high rate performance. Metallic tin has a high theoretical specific capacity (992 mAh / g) and low lithium intercal...

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Problems solved by technology

However, such mixing is difficult, coupled with the low melting point of tin, these make it very difficult to synthesize ultra-small nano-tin particles uniformly dispersed in the porous carbon matrix.

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