A Fe-thiolate layered metal organic framework as a high-performance electrode material for potassium-ion batteries

Abstract

Here, we report a rare example of an Fe-based MOF capable of accommodating K+ ions electrochemically within its layered framework, achieving low polarization, high capacity utilization (∼0.8 electrons exchanged per Fe), and stable cycling performance. In situ Mössbauer spectroscopy and operando XRD analyses revealed that the observed electrochemical storage arises from the Fe3+/Fe2+ redox couple with polyphasic transformations.