Negative electrode material and preparation method thereof, negative electrode plate, electrochemical device and electronic device

Abstract

Provided are a negative electrode material, a method for preparing the same, a negative electrode tab, an electrochemical device, and an electronic device, the negative electrode material comprising: a core comprising: a porous carbon material; the silicon-containing compound Si-M-C is loaded in pores of the porous carbon material, and M is one or more of B, N, O and Al; and a conductive carbon layer on a surface of the core.

Description

technical field [0001] The invention relates to the technical field of electrochemistry, and in particular, to a negative electrode material and a preparation method thereof, a negative electrode pole piece, an electrochemical device and an electronic device. Background technique [0002] One direction of lithium-ion battery technology innovation is to continuously improve energy density. At present, the actual capacity of mainstream graphite materials is close to the theoretical capacity (372mAh / g), and there is a bottleneck in improving energy density. Silicon-based anode materials have attracted much attention and research due to their abundant reserves, ultra-high theoretical capacity (4200mAh / g), and environmental friendliness. However, the volume expansion problem (over 300%) of silicon-based anode materials in the cycle process seriously affects the process of industrial application of silicon-based anode materials. [0003] At present, the main methods to solve the...

AI Technical Summary

Problems solved by technology

However, the volume expansion problem (more than 300%) of silicon-based negative electrode materials in the cycle process has seriously affected the process of industrial application of silicon-based negative electrode materials.

[0003] At present, the main method to solve the large volume change (120% to 300%) and poor conductivity (<0.01S / cm) of silicon materials during the cycle is the nano-silicon materials, silicon materials and graphite or other materials (metal or non-metal) Composite and surface coating, etc., but there are certain defects, such as nanomaterials with large specific surface area, which will consume more electrolyte to form SEI film, resulting in low initial Coulombic efficiency, difficult preparation, and high price; carbon coating is conductive The performance improvement is not obvious, and it cannot solve the electrical contact failure caused by the expansion during the cycle; while the combination with other materials depends on the binder, which will cause the rate reduction

[0004] Therefore, the current lithium-ion battery technology still needs to be improved.

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