NEGATIVE ACTIVE MATERIAL OF LITHIUM-ION SECONDARY BATTERY AND PREPARATION METHOD THEREFOR, NEGATIVE PLATE OF LITHIUM-ION SECONDARY BATTERY, AND LITHIUM-ION SECONDARY BATTERY

摘要

An embodiment of the present invention provides a negative active material of a lithium-ion secondary battery. The negative active material of the lithium-ion secondary battery comprises a silicon-based active material and a nitrogen-doped carbon material. The silicon-based active material is wrapped inside the nitrogen-doped carbon material. The silicon-based active material is one or more types of the following: nanoparticles and nanowires. A micropore is disposed on at least one location of the surface and the interior of the nitrogen-doped carbon material. The material of the nitrogen-doped carbon material is a nitrogen-doped carbon net. The negative active material of the lithium-ion secondary battery solves the problem that the volume change of the material is great when a silicon material is used as a negative active material, which makes the material easy to fall off a collector and results in low electric conductivity. Embodiments of the present invention also provide a method for preparing the negative active material of the lithium-ion secondary battery, a lithium-ion secondary battery negative plate containing the negative active material of the lithium-ion secondary battery, and the lithium-ion secondary battery comprising the negative active material of the lithium-ion secondary battery.