Porous Si‐Cu<sub>3</sub>Si‐Cu Microsphere@C Core–Shell Composites with Enhanced Electrochemical Lithium Storage
Shien Pei, Jianfeng Guo, Zhishun He, Liangai Huang, Tongzhou Lu, Jinyun Gong, Haibo Shao, Jianming Wang
Abstract
Abstract Low‐cost Si‐based anode materials with excellent electrochemical lithium storage present attractive prospects for lithium‐ion batteries (LIBs). Herein, porous Si‐Cu 3 Si‐Cu microsphere@C composites are designed and prepared by means of an etching/electroless deposition and subsequent carbon coating. The composites show a core–shell structure, with a porous Si/Cu microsphere core surrounded by the N‐doped carbon shell. The Cu and Cu 3 Si nanoparticles are embedded inside porous silicon microspheres, forming the porous Si/Cu microsphere core. The microstructure and lithium storage performance of porous Si‐Cu 3 Si‐Cu microsphere@C composites can be effectively tuned by changing electroless deposition time. The Si‐Cu 3 Si‐Cu microsphere@C composite prepared with 12 min electroless deposition delivers a reversible capacity of 627 mAh g −1 after 200 cycles at 2 A g −1 , showing an enhanced lithium storage ability. The superior lithium storage performance of the Si‐Cu 3 Si‐Cu microsphere@C composite can be ascribed to the improved electronic conductivity, enhanced mechanical stability, and better buffering against the large volume change in the repeated lithiation/delithiation processes.