A fluoroxalate cathode material for potassium-ion batteries with ultra-long cyclability.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32144250.
- Also identified by DOI 10.1038/s41467-020-15044-y and PMC identifier 7060185.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Potassium-ion batteries are a compelling technology for large scale energy storage due to their low-cost and good rate performance. However, the development of potassium-ion batteries remains in its infancy, mainly hindered by the lack of suitable cathode materials. Here we show that a previously known frustrated magnet, KFeC2O4F, could serve as a stable cathode for potassium ion storage, delivering a discharge capacity of ~112 mAh g-1 at 0.2 A g-1 and 94% capacity retention after 2000 cycles. The unprecedented cycling stability is attributed to the rigid framework and the presence of three channels that allow for minimized volume fluctuation when Fe2+/Fe3+ redox reaction occurs. Further, pairing this KFeC2O4F cathode with a soft carbon anode yields a potassium-ion full cell with an energy density of ~235 Wh kg-1, impressive rate performance and negligible capacity decay within 200 cycles. This work sheds light on the development of low-cost and high-performance K-based energy storage devices.