MOF‐derived Multi‐Shelled NiP2 Microspheres as High‐Performance Anode Materials for Sodium‐/Potassium‐Ion Batteries

Development of high capacity, high‐rate performance, long cycling life, and low‐cost electrode materials is highly desirable for sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs) to pave the way for their rapid commercialization. Herein, NiP2 nanoparticles loaded in multi‐shelled hollow N‐doped carbon microspheres (NiP2@MHNC) are successfully prepared. The built‐in heterogeneous interfaces between NiP2 and N‐doped carbon promote Na+/K+ diffusion; the robust C–N, N–Ni bonds stabilize the structure of electrodes and accelerate the electrons transfer; and the multi‐shelled hollow structure with large specific surface area effectively buffers the volume expansion to ensure cycling stability. Endowed with the aforementioned synergistic effect, the NiP2@MHNC exhibits remarkable enhancement in electrochemical performance with 346.6 mA h g−1 after 300 cycles for SIB and 142 mA h g−1 after 200 cycles for PIBs at 0.1 A g−1. Moreover, the synergistic effect on electrochemical reaction kinetics is systematically analyzed. Further, the mechanism of sodium storage for NiP2@MHNC is also investigated. The research experience and conclusions in this study based on synergistic effect of heterogeneous interfaces, N‐doped carbon, and multi‐shelled hollow structure open up a meaningful route to design other similar advanced composite electrode materials in energy storage and conversion field. NiP2 nanoparticles loaded in a multi‐shelled hollow N‐doped carbon microspheres (NiP2@MHNC) electrode exhibits distinguished electrochemical performance (346.6 mA h g−1 after 300 cycles for sodium‐ion batteries and 142 mA h g−1 after 200 cycles for potassium‐ion batteries at 0.1 A g−1), benefitting from the synergistic effect of heterogeneous interface, N‐doped carbon, and multi‐shelled hollow structure.