Atomically Dispersed Co Anchored into Highly Nitrogen‐Doped One‐Dimensional Mesoporous Carbon with Large Pore Size for Ultra‐Stable Potassium‐Ion Storage

ABSTRACT Mesoporous carbon materials have emerged as promising candidates for potassium‐ion batteries (PIBs) as anode materials due to their tunable pore structure, excellent conductivity, and high surface area. However, the sluggish reaction kinetics caused by the larger radius of K ions results in poor potassium storage performance. Here, we report a facile tetraethyl orthosilicate‐mediated co‐assembly strategy for anchoring cobalt single atoms into highly nitrogen‐doped mesoporous carbon/carbon nanotubes (Co‐NMC@CNTs). The resulting composite features large mesopore size of approximately 23.7 nm, robust 1D structure, and abundant active sites introduced by Co single atoms and a high nitrogen doping of 13.6 at.%. Synchrotron radiation analysis and theoretical simulation further demonstrate that the presence of Co single atoms significantly reduces diffusion barriers of K ions and increases energy storage centers. When used as PIB anodes, the newly designed Co‐NMC@CNTs electrode demonstrates an exceptional electrochemical performance with a high reversible capacity of 362.3 mAh g ⁻¹ at 100 mA g ⁻¹ after 300 cycles and an outstanding cycling stability with a capacity of 192.0 mAh g ⁻¹ at 1000 mA g ⁻¹ after 4000 cycles. This work opens up a new blueprint for achieving high‐performance mesoporous carbon‐based electrodes in next‐generation energy storage applications.