Antimony Trifluoride-Engineered Hybrid Artificial Interphase Enable Dendrite-Free Potassium Metal Batteries

Abstract

Potassium metal batteries (PMBs) have attracted widespread attention due to high theoretical specific capacity and abundant reserves. However, their further development is constrained by challenges including inhomogeneous deposition and unstable interfaces. Herein, an inorganic/organic hybrid layer (IOHL) comprising KF/Sb and organic polymers PDOL is in situ formed on the K metal surface to synergistically enhance the rapid transport of K⁺ within the SEI and improve the stability of the SEI. Specifically, Sb and K₃Sb function as ion-conductive and electron-regulating phases, facilitating rapid K⁺ transport and balanced electron redistribution. The KF component, with its superior electron-blocking properties, effectively minimizes electron tunneling from the metallic K anode into the electrolyte. Meanwhile, the PDOL polymer provides mechanical elasticity to buffer the volume changes during deposition and stripping. As a result, a uniform and dendrite-free interface is obtained. The assembled symmetric cells exhibit stable cycling performance for 2100 h in carbonate ester-based electrolytes, with a voltage hysteresis of only 100 mV at 0.5 mA cm⁻²/0.5mAh cm⁻². Full cells incorporating perylene-3,4,9,10-tetracarboxylic dianhydride cathode demonstrate an boosted long cycle life and superior rate capability. This work provides valuable insights into developing simple yet effective strategies for constructing a highly stable multifunctional hybrid artificial interphase for PMBs.