MoSe2/N‐Doped Carbon as Anodes for Potassium‐Ion Batteries

By J. Ge, Ling Fan, Jue Wang, Qingfeng Zhang, Zhaomeng Liu, Erjin Zhang, Qian Liu, Xinzhi Yu, Bingan Lu. Advanced Energy Materials, 2018

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Potassium‐ion batteries (PIBs) have attracted considerable attention due to the low redox potential, low price, and abundance, in comparison to lithium and sodium. Herein, a novel potassium MoSe2/N‐C battery with a new electrolyte, 1 m potassium bis(fluoro‐slufonyl)imide in ethyl methyl carbonate, is reported. The MoSe2/N‐C composite, which consists of carbon‐coated MoSe2 nanosheets, is synthesized through solvothermal and annealing method. As an anode material for PIBs, it exhibits an outstanding rate performance and long cycling stability. Meanwhile, a reversible capacity of 258.02 mA h g−1 is achieved after 300 cycles at 100 mA g−1, obtaining a Coulombic efficiency close to 100%. Even at a high current density, it can maintain 218 and 197 mA h g−1 at 500 and 1000 mA g−1, respectively. The charge/discharge mechanism of MoSe2/N‐C as the anode material for PIBs is investigated. These results reveal that the insertion and the extraction of K+ will lead to a phase transition of MoSe2. During the charge process, a part of the MoSe2 will transform to Mo15Se19 and the major final discharge product is K5Se3.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/287e79746bdbe0e243a7805d1194461a74bf0bd4