Low-Strain KVPO4F@C as Hyperstable Anode for Potassium-Ion Batteries

Potassium-ion batteries with carbon-based materials and alloy as anodes possess pronounced potassium storage cycling abilities, yet they suffer from harsh synthetic processes, low initial Coulombic efficiency, limited structure stability. Herein, we first put forward vanadium fluorophosphate (KVPO4F) a highly stable anode material for potassium-ion (PIBs). KVPO4F@C composite is successfully synthesized through hydrothermal method followed by low-temperature roasting process. An amorphous carbon film homogeneously wrapped on the surface of KVPO4F particles to improve electronic conductivity. As PIBs, presents super-high discharge capacity 242.32 mAh g−1 superior cycle stability over 120 cycles at 100 mA·g−1 93.1% retention. Additionally, it maintains 92.9% its 1000 after 2100 times, which indicates an excellent long performance. The in situ X-ray Diffraction ex Transmission Electron Microscopy tests prove minimal volume variation KVPO4F@C. designed provides facilitative conductivity structure, innovating ultra-stable high-performance other energy application fields.