One‐Step Synthesis of Multi‐Core‐Void@Shell Structured Silicon Anode for High‐Performance Lithium‐Ion Batteries

Abstract The core‐void@shell architecture shows great advantages in enhancing cycling stability and high‐rate performance of Si‐based anodes. However, it is usually synthesized by template methods which are complex and environmentally unfriendly and would lead to low‐efficiency charge and mass exchange because of the single‐point van der Waals contact between the Si core and the shell. Here, a facile and benign one‐step method to synthesize multi‐Si‐void@SiO 2 structure, where abundant void spaces exist between multiple Si cores that are multi‐point attached to a SiO 2 shell through strong chemical bonding, is reported. The corresponding electrode exhibits highly stable cycling stability and excellent electrochemical performance. After 200 cycles at a current density of 0.1 A g −1 and then another 200 cycles at 1.2 A g −1 , the electrode outputs a specific capacity of 1440 mAh g −1 . Even at 2.0 A g −1 , it outputs a specific capacity as high as 1182 mAh g −1 . Such an anode can match almost all the cathode materials presently used in lithium‐ion batteries. These results demonstrate the multi‐Si‐void@SiO 2 as a promising anode to be used in future commercial lithium‐ion batteries of high energy density and high power density.