Electrochemical Performance Enhancement of Micro-Sized Porous Si by Integrating with Nano-Sn and Carbonaceous Materials.

ABSTRACT: Silicon is investigated as one of the most prospective anode materials for next generation lithium ion batteries due to its superior theoretical capacity (3580 mAh g^-1), but its commercial application is hindered by its inferior dynamic property and poor cyclic performance. Herein, we presented a facile method for preparing silicon/tin@graphite-amorphous carbon (Si/Sn@G-C) composite through hydrolyzing of SnCl₂ on etched Fe-Si alloys, followed by ball milling mixture and carbon pyrolysis reduction processes. Structural characterization indicates that the nano-Sn decorated porous Si particles are coated by graphite and amorphous carbon. The addition of nano-Sn and carbonaceous materials can effectively improve the dynamic performance and the structure stability of the composite. As a result, it exhibits an initial columbic efficiency of 79% and a stable specific capacity of 825.5 mAh g^-1 after 300 cycles at a current density of 1 A g^-1. Besides, the Si/Sn@G-C composite exerts enhanced rate performance with 445 mAh g^-1 retention at 5 A g^-1. This work provides an approach to improve the electrochemical performance of Si anode materials through reasonable compositing with elements from the same family.

SUBMITTER: Yang T 

PROVIDER: S-EPMC7919461 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature