Potassium-ion batteries (KIBs) are promising electrochemical energy storage systems because of their low cost and high energy density. However, practical exploitation of KIBs is hampered by the lack of high-performance cathode materials. Here we report a potassium manganese hexacyanoferrate (K2Mn[Fe(CN)6]) material, with a negligible content of defects and water, for efficient high-voltage K-ion storage. When tested in combination with a K metal anode, the K2Mn[Fe(CN)6]-based electrode enables a cell specific energy of 609.7 Wh kg−1 and 80% capacity retention after 7800 cycles. Moreover, a K-ion full-cell consisting of graphite and K2Mn[Fe(CN)6] as anode and cathode active materials, respectively, demonstrates a specific energy of 331.5 Wh kg−1, remarkable rate capability, and negligible capacity decay for 300 cycles. The remarkable electrochemical energy storage performances of the K2Mn[Fe(CN)6] material are attributed to its stable frameworks that benefit from the defect-free structure.
Leqing Deng, Jiale Qu, Xiaogang Niu, Juzhe Liu, Juan Zhang, Youran Hong, Meiying Feng, Jiangwei Wang, Miao Hu, Liang Zeng, Qianfan Zhang*, Lin Guo*, Yujie Zhu*. Defect-free potassium manganese hexacyanoferrate cathode material for high-performance potassium-ion batteries. Nat. Commun. 2021, 12, 2167.
https://www.nature.com/articles/s41467-021-22499-0
