Encapsulating Amorphous Manganese–Zinc Bimetallic Phosphides into N-Doped Carbon Nanofibers for High-Rate and Durable Li-/Na-Ion Storage

Transition metal phosphides (TMPs) exhibit significant potential as anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) owing to their high capacity and appropriate voltage platforms, while inevitable volume changes and sluggish kinetics limit their practical applications. Herein, we successfully encapsulate amorphous Mn–Zn bimetallic phosphides into N-doped carbon nanofibers (MZP@NCNFs) by electrospinning, carbonization, and phosphorization processes. The synergistic effect of amorphous Mn–Zn phosphides and N-doped carbon nanofibers facilitates rapid electron and ion transport, thereby effectively enhancing both capacity and rate performance. Besides, this structure can reduce volume changes and prevent nanoparticle agglomeration and pulverization during the cycling process. MZP@NCNFs exhibit an impressive rate capability of 392.3 mA h g–1 at 10 A g–1 and exhibit an outstanding cyclic performance of 854.5 mA h g–1 at 2 A g–1 after 1000 cycles in LIBs. Notably, a capacity of 285.1 mA h g–1 can be retained at 10 A g–1, and a capacity of 313.5 mA h g–1 is maintained after 1000 cycles at 2 A g–1 in SIBs. The amorphous bimetallic phosphides have great potential to enhance the performance for LIBs and SIBs, thus bringing significant advantages in high-performance energy storage material design.