Selective Catalysis‐Mediated Interface to Stabilize Antimony Atom‐Cluster Anode for Robust Potassium‐Ion Batteries

Abstract Controlling the electrode‐electrolyte interfacial behavior is crucial for achieving a high‐quality solid electrolyte interphase (SEI) and ensuring sustainable battery performance. Here, we propose a selective catalysis strategy to stabilize antimony atom‐cluster (Sb SA‐AC ) anode/electrolyte interface for robust potassium‐ion batteries (PIBs). Specifically, the electrode featuring Sb SA‐AC in porous carbon (Sb SA‐AC /PC) as “electrocatalyst” unduly catalyzes the reduction of the dimethyl ether‐based electrolyte, resulting in loose SEI layer and rapid capacity decay. While in triethyl phosphate‐based electrolyte, the Sb SA‐AC /PC selectively catalyzes the preferential decomposition of anions and the polymerization of solvent molecules, leading to a bilayer SEI with inner inorganic‐rich components and an outer elastic polyphosphate layer, which improve the interface stability and electrochemical performance. Thus, the Sb SA‐AC /PC maintains a long‐term stability over 12 months and demonstrates long‐cycling stability over 4000 cycles with a capacity retention of 96%. This research establishes a correlation between electrode/electrolyte interactions and SEI characteristics, providing a new insight for advanced interface engineering in high‐performance PIBs and beyond.