Enhanced performance of yolk-shell SiO/MWCNTs@C composites bridged by MWCNTs for high-performance lithium-ion battery anodes
Ziyi Zhou, Zhifeng Li, Xiaojuan Liu, Jiayi Wu, Ke Li, Chunxiang Wang
Abstract
Silicon oxide (SiO) is a promising anode material for lithium-ion batteries; however, it suffers from significant drawbacks, such as poor electrical conductivity and substantial volume expansion during cycling. To address these challenges, a yolk-shell structured nanospherical anode material (SiO/MWCNTs@C) was synthesized. In this material, multi-walled carbon nanotubes (MWCNTs) are positioned between the silicon oxide (SiO) core and the outer carbon layer, acting as a bridging component. This design enhances lithium ion diffusion, conductivity, and cycling stability, significantly improving its electrochemical performance as an anode material in lithium-ion batteries. The material demonstrates an initial coulombic efficiency of 76.18 %, and even after 200 cycles at a current density of 5000 mA·g −1 , it retains a reversible specific capacity of 844 mAh·g −1 , with a capacity retention rate of 92 %. These findings suggest that the developed SiO/MWCNTs@C composites are a viable solution for enhancing the performance of silicon-based anodes in next-generation lithium-ion batteries.