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

• Main Authors: Tiantian Yang, Hangjun Ying, Shunlong Zhang, Jianli Wang, Zhao Zhang, Wei-Qiang Han
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Materials
• Subjects: Si/Sn@G-C composite; Lithium-ion battery; tin; porous silicon; anode material
• Online Access: https://www.mdpi.com/1996-1944/14/4/920

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.