Ball-Milling Strategy for Fast and Stable Potassium-Ion Storage in Antimony-Carbon Composite Anodes

Potassium-ion batteries (PIBs) have been considered as promising alternatives to lithium-ion batteries in large-scale energy storage systems owing to the high earth abundance and low cost of potassium resources. However, the large radius of the K ion hinders the development of suitable electrode materials. Herein, with commercial antimony (Sb) and mesoCarbon microbead (MCMB) powders as low-cost raw materials, a facile ball-milling strategy is developed for constructing high-performance Sb−C composite electrodes. The as-prepared Sb@MCMB-3 electrode exhibits high reversible capacity (525.4 mAh g⁻¹ at 100 mA g⁻¹), superior rate capability (293.9 mAh g⁻¹ at 5000 mA g⁻¹) and stable cycling performance (497.5 mAh g⁻¹ after 80 cycles at 100 mA g⁻¹ and 300.1 mAh g⁻¹ after 500 cycles at 1.0 A g⁻¹). With consecutive CV measurements, the galvanostatic intermittent titration technique, and Randle-Sevcik equation, the K-ion diffusion kinetics are insightfully evaluated. Therefore, this work may broaden the pathways for the commercialization of PIBs.