Regulating Interfacial Ion and Electron Transport for Dendrite‐Free Potassium Metal Anodes

Abstract Potassium metal batteries (PMBs) face challenges of interfacial instability and dendritic growth. Herein, an integrated potassium metal anode (K‐Cu@OC) is fabricated by cold‐rolling metallic K with an intermediate medium composed of Cu nanoparticle‐embedded oxygen‐doped carbon composite, enabling simultaneous regulation of ion transport and electron localization at the interface. Experimental and theoretical analyses indicate that oxygen species functional groups boost K ⁺ transport kinetics and guide uniform nucleation. Meanwhile, the Cu/OC heterointerface promotes directional electron transfer and spatially regulated K ⁺ uniform deposition by establishing localized electron‐rich regions. Consequently, the anode interface remains dendrite‐free and exhibits enhanced electrochemical stability. The symmetric cell exhibits exceptional cycling stability exceeding 2800 h at 0.5 mA cm ⁻² and 1480 h at 1.0 mA cm ⁻² . Furthermore, the full cell maintains a reversible capacity of 93.4 mAh g ⁻² over 600 cycles with minimal voltage hysteresis. This work highlights the critical role of interfacial chemical and electronic engineering in stabilizing K metal anodes, providing a scalable and practical strategy for achieving high‐performance PMBs.