Approaching Reactive KFePO<sub>4</sub> Phase for Potassium Storage by Adopting an Advanced Design Strategy
Irin Sultana, Md Mokhlesur Rahman, Srikanth Mateti, Neeraj Sharma, Shaoming Huang, Ying Chen
Abstract
Abstract Pristine KFePO 4 is electrochemically inactive towards potassium, which suggests that K + ion migration is unfavorable in the KFePO 4 structure. Therefore, it is a challenge to create a reactive structure of KFePO 4 towards reversible potassium insertion/extraction. In this study, we have fabricated reactive KFePO 4 phase by adopting high‐energy ball milling technique where tiny nanoparticles (∼1.0‐1.5 nm) of KFePO 4 are created and embedded in the Super P carbon black matrix, which provides conductivity and helps to stabilize the electrode structure. The combination of nano‐sizing and the conductive matrix appears to activate electrochemical reactivity. The obtained carbon incorporated KFePO 4 material appears to be amorphous. The electrode produces an average operational potential of ∼2.5 V (vs K + /K) with high capacity retention of 90 mAh g −1 . It is anticipated that this work could pave the way for further studies on cathodes and generate huge attention to the role of ball milling and particle size control on electrochemical activity of KFePO 4 materials for the development of PIBs.