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.

中文翻译：

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MoSe2 / N掺杂碳作为钾离子电池的阳极

与锂和钠相比，钾离子电池（PIB）由于具有较低的氧化还原电位，低廉的价格和丰度而备受关注。本文报道了一种新型的MoSe ₂ / N-钾钾电池，其中含有一种新的电解质，即在碳酸甲乙酯中的1 m双（氟代磺酰）亚胺钾。MoSe ₂ / N-C复合材料由碳包覆的MoSe ₂纳米片组成，是通过溶剂热和退火方法合成的。作为PIB的负极材料，它具有出色的倍率性能和长循环稳定性。同时，258.02毫安Hg的可逆容量^-1在100mA克300次循环后达到^-1，库仑效率接近100％。即使在高电流密度下，它也可以分别在500和1000 mA g ^-1下维持218和197 mA hg ^-1。研究了MoSe ₂ / NC作为PIB阳极材料的充放电机理。这些结果表明，K ⁺的插入和提取将导致MoSe ₂的相变。在充电过程中，一部分MoSe ₂将转变为Mo ₁₅ Se ₁₉，而最终的主要放电产物为K ₅ Se ₃。