Blowing Iron Chalcogenides into Two-Dimensional Flaky Hybrids with Superior Cyclability and Rate Capability for Potassium-Ion Batteries

Chalcogenide-based anodes are receiving increasing attention for rechargeable potassium-ion batteries (PIBs) due to their high theoretical capacities. However, they usually exhibit poor electrochemical performance structural stability, low conductivity, and severe electrolyte decomposition on the reactive surface. Herein, a method analogous blowing bubbles with gum is used confine FeS2 FeSe2 in N-doped carbon PIB ultrahigh cyclic stability enhanced rate capability (over 5000 cycles at 2 A g-1). Several experimental methods employed understand electrodes' performance. The density functional theory calculations showed affinity potassium adsorption FeSe2. situ XRD ex TEM analysis confirmed formation of several intermediate phases general formula KxFeS2. These have conductivity large interlayer distance, which promote reversible insertion facilitate charge transfer. Also, calculated diffusion coefficient during charge/discharge further proves kinetics. Furthermore, FeS2@NC anode full cell also exhibits (88% capacity retention after 120 99.9% Coulombic efficiency). Therefore, this work provides not only an approach overcome challenges but comprehensive understanding mechanism kinetics interaction chalcogenides.