Preparation method of ordered mesoporous silicon-carbon composite material

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of an ordered mesoporous silicon-carbon composite material, the ordered mesoporous silicon-carbon composite material is obtained by reverse replication of a mesoporous structure of a molecular sieve, the mesoporous carbon structure in a template is ordered and stable and is tightly combinedwith the wall, and the ordered carbon material also has good conductive activity. If the template containing silicon is reduced to obtain a silicon-carbon composite material sandwiched by ordered mesoporous carbon, the material can effectively solve the problem of structural collapse and pulverization caused by volume expansion of silicon in the circulation process, and can also solve the defectof poor electrical conductivity of the silicon material by utilizing the porous carbon material with good conductivity; the capacity loss caused by agglomeration of the silicon particles in the circulation process can also be prevented; therefore, the ordered mesoporous silicon-carbon composite material negative electrode shows excellent cycle performance.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for preparing an ordered mesoporous silicon-carbon composite material. Background technique [0002] With the rapid development of new energy vehicles, advanced consumer electronics, large-scale energy storage and other fields, the energy density requirements of lithium-ion batteries are increasing day by day. Improving the energy density of batteries is not only conducive to improving the cruising range of electric vehicles, but also can Significantly reduce the cost of the battery. At present, the cathode material NCM811 and NCA material technology is relatively mature, but the corresponding anode material commercialized graphite anode material can no longer meet the needs of the current high specific energy battery due to its low gram capacity, so it is urgent to develop high gram capacity negative electrode material. [0003] Silicon-based materials ha...

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Problems solved by technology

[0002] With the rapid development of new energy vehicles, advanced consumer electronics, large-scale energy storage and other fields, the energy density requirements of lithium-ion batteries are increasing day by day. Improving the energy density of batteries is not only conducive to improving the cruising range of electric vehicles, but also can Significantly reduce the cost of the battery. At present, the cathode material NCM811 and NCA material technology is relatively mature, but the corresponding anode material commercialized graphite anode material can no longer meet the needs of the current high specific energy battery due to its low gram capacity, so it is urgent to develop high gram negative electrode material

[0003] Silicon-based materials have a high gram capacity of 4200mAh / g, which has attracted the attention and research of many material manufacturers. However, due to the large volume expansion of pure silicon materials during the cycle, the active materials are pulverized and fall off from the current collector, and the capacity rapidly decays; at the same time Silicon itself is a semiconductor material with poor conductivity, so it is difficult to commercialize

[0004] Based on some defects above the silicon material, most of the material manufacturers currently use silicon oxide and nano-silicon respectively with simple physical compounding of graphite, but the material performance is poor, and the long-life cycle of the battery cannot be guaranteed.

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