Scalable Synthesis of a Porous Micro Si/Si-Ti Alloy Anode for Lithium-Ion Battery from Recovery of Titanium-Blast Furnace Slag
Yong Liu, Yanjun Zhong, Zhihua Zeng, Pan Zhang, Hao Zhang, Ziqiang Zhang, Fan Gao, Xiaodong Ma, Mauricio Terrones, Ye Wang, Yanqing Wang
Abstract
The extensive utilization of Si-anode-based lithium-ion batteries faces obstacles due to their substantial volume expansion, limited intrinsic conductivity, and low initial Coulombic efficiency (ICE). In this study, we present a straightforward, cost-effective, yet scalable method for producing a porous micro Si/Si-Ti alloy anode. This method utilizes titanium-blast furnace slag (TBFS) as a raw material and combines aluminothermic reduction with acid etching. By adjusting the Al:TBFS ratio, the specific surface area of the material can be facilely tailored, ranging from 25.89 to 43.23 m 2 g –1, enhancing the ICE from 78.2 to 85.5%. The incorporation of the Si-Ti alloy skeleton and porous structure contributes to the enhanced cyclic stability (capacity retention from 50.7 to 96.9%) and conductivity ( R ct from 107.7 to 76.6 Ω). The Si/Si-Ti anode exhibits excellent electrochemical performance, including delivering a specific capacity of 1161 mAh g –1 at 200 mA g –1 after 200 cycles and 1112 mAh g –1 at 500 mA g –1 after 100 cycles, with an improved ICE of 81.2%. This study introduces a successful methodology for designing novel Si anodes from recycling waste materials, providing valuable insights for future advancements in this area.