211 / 2022-02-15 08:07:20

Three-dimensional Honeycomb-liked MoP@C Nanocomposite with Advanced Sodium/Potassium ion Storage Performance

MoP@C nanocomposite; Three-dimensional honeycomb-liked structure; Sodium-ion battery; Potassium-ion battery.

Mineral Materials and Advanced Energy Materials > 8. New Energy Materials

ABSTRACT: MoP@C nanocomposite, combined three-dimensional (3D) honeycomb-liked carbon matrix with molybdenum phosphide, was synthesized through a simple hard template method followed by high-temperature phosphating treatment. Here, the MoP@C nanocomposite has shown excellent sodium and potassium-ion storage properties applied as anode materials for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs), superior to those traditional composites. 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 under 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. For instance, the exquisite porous nano-frame with higher conductivity and larger specific surface area, provides full contact opportunities between the electrolyte and the active material, and successfully shorts the diffusion distance of electrons and ions. Moreover, the stable three-dimensional carbonaceous 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 MoP@C electrode. The satisfying result has laid a solid foundation for the development of MoP in the field of electrochemical energy storage.