Negative electrode material preparation method, negative electrode material, negative electrode piece and lithium ion battery

Abstract

The invention provides a negative electrode material preparation method, a negative electrode material, a negative electrode piece and a lithium ion battery. The negative electrode material preparation method comprises the following steps: mixing and heating a core material and a heteroelement-containing polymer or a heteroelement-containing ionic liquid; mixing and heating the core material coated with the heteroelement-containing polymer or the heteroelement-containing ionic liquid and functionalized graphene; and sintering the functionalized graphene, the heteroelement-containing polymer orthe heteroelement-containing ionic liquid and the core material to obtain the negative electrode material with the surface of the core material being fixedly coated with the graphene by doping carbon. The negative electrode material preparation method allows the negative electrode material with the core material coated with doped carbon fixed graphene to be obtained through fixing graphene by doping carbon, so graphene is stably fixed on the surface of the core material, and graphene agglomeration is avoided.

Description

technical field [0001] The present application relates to the field of lithium ion batteries, and more specifically, relates to a method for preparing negative electrode materials, negative electrode materials, negative electrode sheets and lithium ion batteries. Background technique [0002] With the popularity of electronic products in recent years, lithium batteries as their power sources have become more and more popular due to their advantages such as light weight, small size, high working voltage, high energy density, high output power, high charging efficiency and no memory effect. Pay attention to. However, due to the bottleneck of the energy density of lithium-ion batteries, it has been criticized by users. In view of the fact that the energy density bottleneck of lithium-ion batteries is not easy to break through, researchers are now focusing on the fast charging performance of lithium-ion batteries as the current main research direction, and strive to make the pe...

AI Technical Summary

Problems solved by technology

However, graphene has defects such as huge specific surface area and easy agglomeration. If it is used in lithium-ion batteries, it will reduce the service life of the battery, block the transmission of lithium ions, low efficiency for the first time, and the electrode sheet cannot be prepared. It is currently not commercially available.

[0004] The patent US8580432B2 provides a negative electrode material. The application is to mix and granulate nano-graphene sheets, nano-negative electrode materials and carbon source materials, and then carbonize to obtain carbon-coated nano-graphene and nano-negative electrode material particles. However, graphene in this material is still distributed randomly, which makes the specific surface area of ​​the material huge, and it is not easy to prepare a pole piece. At the same time, graphene has no chemical bonds to fix, so that the material cannot be used due to the agglomeration of graphene, and the battery life is seriously affected. influences

[0005] In the current negative electrode materials of lithium-ion batteries, graphene still exists agglomeration, so the chaotic distribution and agglomeration of graphene cause the specific surface area of ​​the battery to be huge, which hinders the transmission of lithium ions, resulting in a slow charging rate and low service life of the battery. question,

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