Rational Construction of Advanced Potassium Ion Diffusion and Storage Matrix

Abstract Developing new electrode materials with a regular channel for stable storage and diffusion of potassium (K) ions is crucial to alleviating the ubiquitous problems in K‐ion batteries (KIBs) such as slow diffusion rate, huge volume expansion, and unstable interface by the large K ion radius. Herein, electrode material with a facile diffusion pathway, vast space for volume expansion, and good interfacial compatibility are found to be necessary. Fluoride graphdiyne (F‐GDY) is illustrated for its expanded conductive skeleton, uniform structural pores, and well‐distributed F atoms. First‐principles computations and electrochemical characterizations reveal the high reversible capacity and cyclic stability for the instanced F‐GDY electrode through the ultralow diffusion barrier, abundant exposed active sites, and stable KF‐enriched solid electrolyte interphase film. The F‐GDY anode exhibits a capacity of 320 mAh g −1 at 50 mA g −1 , and 120 mAh g −1 at 1000 mA g −1 for 1800 cycles. These electrochemical performances of F‐GDY anode are superior than those of many other carbon materials reported to date, providing us with a new insight into the design of an electrode for KIBs.