Fabricating Potassiophilic Alloy Anode with Liquid Metal Enables Superior Potassium Ion Deposition

Designing three-dimensional carbon skeleton represents an effective strategy for achieving dendrite-free potassium metal batteries. Herein, a freestanding electrode composed of carbon nanofibers loaded with potassiophilic Gallium-indium-nickel alloy nanoparticles (GaInNi@CNF), synthesized with the assistance of liquid metal (GaIn), is proposed as the anode host for the potassium metal batteries. The incorporation of GaIn enables the formation of a GaInNi alloy with nickel, thereby enhancing the adsorption energy of potassium. The synergistic effect of uniformly distributed alloy nanoparticles and their surrounding edge graphite carbon promotes uniform nucleation and stable potassium deposition. With the K-GaInNi@CNF-based modified electrode, the assembled K-GaInNi@CNF symmetric cells can achieve stable cycling over 800 h at 2 mA cm-2. Full cells with PTCDA cathode and K-GaInNi@CNF anode exhibit high stability (with a capacity retention rate of 81.75% for 800 cycles at 1 A g-1) with 99% Coulombic efficiency. Additionally, the cycle performance of GaInNi@CNF||KPTCDA anode-free cells is studied, and 77.52% capacity retention is achieved at 0.05 A g-1 after 50 cycles. This liquid metal-assisted method described in this study provides a strategy in developing electrodes for rechargeable batteries.