Nano‐confining Red Phosphorus in a Carbon Hierarchical Superstructure for Superior Potassium Storage

Abstract High‐capacity red phosphorus is a promising candidate for anode material of potassium‐ion batteries while the poor electrical conductivity and large volume variation may cause severe material pulverization and performance deterioration during cycling. Incorporation of red phosphorous with porous carbon substrates is a potential strategy to solve these issues, which can spatially confine the phosphorus particles and promote mass/charge transfer processes. Herein, a hierarchical nitrogen‐doped microporous carbon superstructure derived from nanorod‐assembled metal‐organic framework superstructure was presented to confine red phosphorus (P@NCS) for potassium storage. Remarkably, P@NCS as an anode material demonstrated a high reversible specific capacity of 551 mAh g⁻¹ at 0.1 A g⁻¹ after 100 cycles along with a high initial Coulombic efficiency of 76 %. Control experiments and theoretical calculations verified that the excellent potassium storage performance was attributed to the strong confinement effect of the nitrogen‐doped micropores and the unique nanorod‐assembled superstructure. Furthermore, a potassium‐ion full cell was assembled using P@NCS and 3,4,9,10‐perylenetetracarboxylic dianhydride as anode and cathode material respectively, demonstrating the great potential of P@NCS for practical potassium‐ion batteries.