Fabrication of CoSe@NC nanocubes for high performance potassium ion batteries

Authors：Huang, Qianhui; Fan, Xinming^*; Ou, Xing; Wang, Hua; Wu, Lijue; Yang, Chenghao^*

Source：Journal of Colloid and Interface Science, 2021, 604: 157-167.

DOI：10.1016/j.jcis.2021.06.162

• Potassium-ion batteries
• Anode
• CoSe@NC
• Electrochemical performance

Potassium-ion batteries (PIBs) are considered as a promising candidate for large-scale energy storage. While exploring suitable anode materials are of vital need for the practical applications of PIBs. Herein, a well-designed heterostructured anode material CoSe nanocubes wrapped by N-doped carbon (CoSe@NC), has been successfully fabricated by simple annealing ZIF-67 nanocubes followed by in-situ selenization process. It is noted that ZIF-67 nanocubes are used as an effective template for the formation of porous structure, which can facilitate the construction of heterogeneous interface between CoSe and N-doped carbon (NC), effectively stabilizing CoSe with conversion reaction product Co0, increasing the diffusion mobility of electrons and K+-ions, and alleviating huge volume change. As expected, the heterostructured CoSe@NC nanocubes exhibit excellent K+-storage performance, which can display a rather high initial charge capacity (388.7 mAh g-1 at 0.1 A g-1 with the columbic efficiency of 70%), supe-rior cyclic stability (309.6 mA h g-1 after 500 cycles at 2 A g-1), and exceptional rate capability (365.9 mAh g-1 at 2 A g-1). In terms of the low-cost and facile production approach for CoSe@NC, which makes the CoSe@NC a promising anode material for PIBs.