Three‐dimensional Honeycomb MoP@C Nanocomposite with Advanced Sodium/Potassium Ion Storage Performance.

MoP@C nanocomposite, combined three‐dimensional (3D) honeycomb carbon matrix with molybdenum phosphide, was synthesized through a simple hard template method followed by high‐temperature phosphating treatment. The MoP@C has shown excellent sodium and potassium‐ion storage properties applied as anode materials for sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs). The MoP@C composite maintains a high reversible specific capacity of 250 mAh g−1 in SIBs after 100 cycles at 0.5 A g−1. Furthermore, even at a high current density of 5 A g−1, it still delivers a specific capacity of 200.5 mAh g−1. Additionally, the nanocomposite holds 147.2 mAh g−1 at a high current density of 1 A g−1 in PIBs. The excellent electrochemical performance benefits from the synergistic effect of the hierarchical MoP@C nanostructure. The exquisite porous nano‐frame with higher conductivity and larger specific surface area, the active substance is fully infiltrated in the electrolyte, and successfully shortens the diffusion distance of electrons and ions. Moreover, the cavity in the heterostructure effectively inhibits the instinctive aggregation of MoP and simultaneously alleviates the volume expansion during the intercalation and deintercalation of ions in the charge and discharge process, enabling the excellent rate performance and long cycle life of the MoP@C electrode. The designed MoP@C composite shows excellent electrochemical cycle performance and rate performance as anode materials for sodium/potassium‐ion batteries. The MoP@C composite maintained a high reversible specific capacity of 250 mAh g−1 in sodium‐ion batteries after 100 cycles at the current density of 0.5 A g−1. Furthermore, even at a high current density of 5 A g−1, it still delivered a specific capacity of 200.5 mAh g−1. Moreover, MoP@C composite materials also show excellent performance as anode material of potassium‐ion batteries, with a specific capacity of 147.2 mAh g−1 at the high current density of 1 A g−1. In summary, the excellent electrochemical performance of MoP@C composite materials fully proves that they can greatly improve the stability of the structure and reversibility as electrode materials, and lays a foundation for the further application of electrochemical energy storage devices in large‐scale applications. [ABSTRACT FROM AUTHOR]