摘要
Potassium-based batteries, including potassium-ion (PIBs) and potassium metal batteries (PMBs), are gaining attention as alternatives to lithium-ion batteries (LIBs). However, potassium's large ionic radius (1.38 & Aring;) reduces charge density, weakens solvation, and increases energy barriers for K+ diffusion, leading to slower reaction kinetics, thicker solid electrolyte interphase (SEI) layers, and dendrite formation. To address these challenges, a novel single-atom Fe-N-4 dipole-dipole coupling (SA.Fe) is proposed. The unique Fe-N-4 coordination and highly conductive Ketjen black (KB) substrate establish a rapid horizontal electron transfer network, enhancing electrode interface reactions. Moreover, Fe-N-C coordination generates a short-range polar electric field, improving K+ affinity and diffusion. This coherent single-atom coupling effectively regulates K+ migration, significantly enhancing reaction kinetics and lowering diffusion barriers. The SA.Fe anode delivers high reversible capacities (446.3 mAh g(-1)) and exceptional durability (10 000 cycles at 2.0 A g(-1)) in PIBs, alongside remarkable stability (600 cycles at 0.5 mA cm(-2)) and fast potassium metal (K metal) deposition without dendrite formation in PMBs. This study highlights the potential of coherent single-atom dipole coupling for efficient K+ storage and dendrite-free batteries, offering a promising pathway for next-generation potassium-based energy systems.