Bark‐Inspired Functional‐Carbon/Potassium Composite Electrode with Fast Ion Transport Channels for Dendrite‐Free Potassium Metal Batteries

Abstract Potassium metal batteries (PMBs) are regarded as viable candidates for future electrochemical energy storage devices with potential high energy density and low cost. However, uncontrollable potassium dendrite growth and huge volume expansion severely inhibit the practical application of PMBs. Herein, inspired by the structure and functionalities of tree bark, an antimony (Sb) nano‐clusters decorated N‐doped interconnected carbon nanospheres/potassium composite electrode with biomimetic fast ionic channels is developed to realize the dendrite‐free potassium metal batteries. The composite electrode provides abundant nucleation sites and interconnected ion transport channels, facilitating rapid ion transport kinetics and highly reversible potassium plating/stripping behaviors. Consequently, the assembled symmetric cell exhibits an ultra‐long cycle life (1100 h at 1.0 mA cm⁻²/1.0 mAh cm⁻²) in carbonate electrolyte. Moreover, the K full cells demonstrate enhanced cycling stability (1500 cycles at 8 C) and rate capacity (117.27 mAh g⁻¹ at 20 C). This novel biomimetic design of composite anode presents an effective and rational approach for achieving stable PMBs.