Positive electrode active material for lithium ion secondary battery and preparation method thereof, positive electrode piece for lithium ion secondary battery, and lithium ion secondary battery

摘要

Embodiments of the present invention provide a positive electrode active material for a lithium ion secondary battery, and the positive electrode active material for a lithium ion secondary battery includes a silicon-based active material and a nitrogen-doped carbon material. The silicon-based active material is wrapped inside the nitrogen-doped carbon material, and the silicon-based active material is one or more of nanoparticles and nanowires; the pores are at least one of the outside and inside of the nitrogen-doped carbon material The material of the nitrogen-doped carbon material is a nitrogen-doped carbon network. In the prior art, the positive electrode active material for a lithium ion secondary battery is easily dropped from the current collector due to a large volume change and has low conductivity when a silicon material is used as the positive electrode active material. Solve a problem. Embodiments of the present invention also provide a method for preparing a positive electrode active material for a lithium ion secondary battery, a positive electrode piece for a lithium ion secondary battery including a positive electrode active material for a lithium ion secondary battery, and a positive electrode for a lithium ion secondary battery A lithium ion secondary battery including an active material is provided.