Bismuth–Antimony Alloy Nanoparticle@Porous Carbon Nanosheet Composite Anode for High-Performance Potassium-Ion Batteries

作者：Peixun Xiong, Junxiu Wu, Mengfan Zhou, Yunhua Xu · 发表于：ACS Nano · 年份：2019 · 被引用次数：248 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Supercapacitor Materials and Fabrication

Antimony (Sb)-based anode materials have recently aroused great attention in potassium-ion batteries (KIBs), because of their high theoretical capacities and suitable potassium inserting potentials. Nevertheless, because of large volumetric expansion and severe pulverization during potassiation/depotassiation, the performance of Sb-based anode materials is poor in KIBs. Herein, a composite nanosheet with bismuth–antimony alloy nanoparticles embedded in a porous carbon matrix ( [email protected] ) is fabricated by a facile freeze-drying and pyrolysis method. The introduction of carbon and bismuth effectively suppress the stress/strain originated from the volume change during charge/discharge process. Excellent electrochemical performance is achieved as a KIB anode, which delivers a high reversible capacity of 320 mA h g –1 after 600 cycles at 500 mA g –1 . In addition, full KIBs by coupling with Prussian Blue cathode deliver a high capacity of 396 mA h g –1 and maintain 360 mA h g –1 after 70 cycles. Importantly, the operando X-ray diffraction investigation reveals a reversible potassiation/depotassiation reaction mechanism of (Bi,Sb) ↔ K(Bi,Sb) ↔ K 3 (Bi,Sb) for the [email protected] composite. Our findings not only propose a reasonable design of high-performance alloy-based anodes in KIBs but also promote the practical use of KIBs in large-scale energy storage.