关键字：NANOPARTICLES; NANOSHEETS; GRAPHITE

摘要：Bismuth has gained increasing attention as anodes for advanced potassium-ion batteries because of its high theoretical capacity and suitable voltage plateaus. Although nanosized Bi structures display better properties, their syntheses still remain a great challenge because the low melting point of Bi makes it easily to aggregate into large ingots. Herein, the thin Bi4Se3 coating layer combined with N-doped carbon was introduced onto the Bi nanospheres to chemically confine their overgrowth via an in-situ selenization process. Theoretical calculation and experimental results indicated that the Bi4Se3 coating layer not only exhibits better affinity towards Bi-atoms compared with that of carbon sheet, but also can boost the K-ion diffusion kinetics. In addition, the Bi4Se3 coating layer was unraveled to undergo a reversible conversion/alloying mechanism with unique final dis-charged products of K3BiSe3 and K3Bi, which was responsible for the improved discharge capacity and better cycle properties (A higher capacity of 300 mAh/g maintained after 50 cycles, while it was only 210 mAh/g for the Bi@C electrode). Our work presents an effective and general approach to circumvent the overgrowth issues of bismuth anodes and other metal anodes with low melting points for advanced battery applications.

卷号：621

期号：

是否译文：否