Bi2S3–CoS@C core- shell structure derived from ZIF-67 as anodes for high performance lithium-ion batteries

Abstract The combination of multiple active components and engineering of reasonable structures are effective strategies to prepare high-performance electrochemical electrodes. Herein, a specially designed Bi2S3–CoS@C core-shell structure is synthesized using ZIF-67 as a template, in which nanoparticles of Bi2S3 and CoS in the composites are surrounded by a carbon layer with a sufficient amount of hollow space. This structure is conducive to the transport of ions, an increase in the conductivity and accommodating the volume change of the active materials during cycling. When applied as an anode for lithium-ion batteries, the Bi2S3–CoS@C electrode exhibits excellent electrochemical properties, displaying an excellent specific capacity of 1390 mAh g−1 at a current density of 100 mA g−1 after 100 cycles. During a long cycling test, an excellent reversible capacity of 836.2 mAh g−1 can also be obtained at a high current density of 1 A g−1 after 300 cycles. This work sheds light on an efficient approach to build novel high-performance electrodes for energy devices.