电化学
电解质
钾
阳极
石墨
阴极
插层(化学)
钾离子电池
碳酸乙烯酯
化学工程
无机化学
材料科学
化学
磷酸钒锂电池
电极
物理化学
冶金
工程类
作者
Leqing Deng,Tianshuai Wang,Youran Hong,Meiying Feng,Ruiting Wang,Juan Zhang,Qianfan Zhang,Jiangwei Wang,Liang Zeng,Yujie Zhu,Lin Guo
出处
期刊:ACS energy letters
[American Chemical Society]
日期:2020-05-18
卷期号:5 (6): 1916-1922
被引量:76
标识
DOI:10.1021/acsenergylett.0c00912
摘要
The application of a layered K0.5MnO2 cathode in potassium-ion batteries is limited by its poor cycling performance when charged above 4.0 V (vs K+/K), and the underlying mechanism for this electrochemical instability is still unclear. Here, it is discovered that ethylene carbonate (EC) will intercalate into the depotassiated K0.5MnO2, causing the exfoliation of the layered compound and the capacity decay under high charge cutoff voltage. When the carbonates are replaced with a nonflammable phosphate, the electrochemical performance of K0.5MnO2 above 4.0 V (vs K+/K) is significantly enhanced with a large reversible capacity (120 mAh g–1) and high capacity retention of 84% after 400 cycles. This phosphate-based electrolyte also demonstrates good compatibility with the commercial graphite anode, enabling the encouraging electrochemical performance of the K0.5MnO2|graphite full-cell. The present study provides new insights on further exploration of other electrolytes to advance the emerging low-cost and high-performance potassium-ion batteries.
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