Long-Cycling and High-Rate Potassium Storage Enabled by Sulfur-Doped Carbon Derived from Disposable Chopsticks

Carbonaceous materials are a class of promising anode candidates for potassium ion batteries, while the practical implementation is handicapped by a limited interlayer, inferior structural stability, and relatively low specific capacity. Herein, scalable sulfur-doped carbon (SCC2) is developed via facile pyrolysis with disposable chopsticks and low-cost sulfur as precursors. Its properties of enlarged interplane distance, increased defect sites, stable hierarchical structure, and uniform sulfur doping bestow it with superior long-term cycling performance of 305.85 mAh g–1 after 2000 cycles at 1.0 A g–1 and excellent rate capability of 210.57 mAh g–1 at a high current density of up to 5.0 A g–1. The excellent performance of SCC2 could be attributed to the appropriate sulfur doping increasing the graphite layer spacing and introducing additional active sites, which are proper for potassium storage.