Sulfur-doped hollow porous carbon spheres as high-performance anode materials for potassium ion batteries

• Published in: Journal of energy storage Vol. 72; p. 108297
• Main Authors: Sun, Qianqian, Mu, Jinglin, Ma, Fanteng, Li, Yanyan, Zhou, Pengfei, Zhou, Tong, Wu, Xiaozhong, Zhou, Jin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.11.2023
• Subjects: Anode material; Carbon material; Hollow porous carbon spheres; Potassium ion batteries; Sulfur doping; Anode material; Potassium ion batteries; Carbon material; Hollow porous carbon spheres; Sulfur doping
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2023.108297

Hard carbons, due to their advantages of abundant sources, stable chemical properties, and easily adjustable structure, have been widely applied as anode materials for potassium ion batteries (PIBs). However, hard carbon still suffers from low storage capacity and structural instability. Sulfur doping has been demonstrated an effective strategy to solve these issues. Here, a series of sulfur-doped hollow porous carbon spheres (SHPCS) with different S-doping amounts are facilely prepared via a direct sulfurization process by elemental sulfur. It is found that S-doping effectively modulates the nano-micro structure of SHPCS, and thereby promote the full utilization of active sites. Notably, the optimized SHPCS achieves a prominent reversible and cycling stability (454 mAh g−1 at 50 mA g−1; 211.4 mAh g−1 at 1000 mA g−1 for 1000 cycles, a capacity retention of 93.7 %). Our work provides an efficient strategy for the design of hard carbon anodes for high-performance PIBs. [Display omitted] •Sulfur-doped hollow porous carbon spheres are obtained through a direct sulfurization with element sulfur as sulfur source.•The nano-micro structure of hollow carbon sphere is effectively modulated by sulfur doping.•The optimized SHPCS achieves a prominent rate performance and excellent cycling stability.•The DFT calculations show that sulfur doping in carbon favors the pseudocapacitive storage of K+.