In Situ Fabrication of Ni₂P Nanoparticles Embedded in Nitrogen and Phosphorus Codoped Carbon Nanofibers as a Superior Anode for Li-Ion Batteries

A facile and cost-effective method has been developed for the fabrication of Ni₂P nanoparticles encapsulated in N,P-codoped carbon nanofibers (Ni₂P@NPCNFs) using the commercialized products of melamine polyphosphate (MPP) and Ni foam. During the synthetic process, MPP serves as the solid phosphorus source for the phosphidation of Ni foam, and it simultaneously performs as a carbon source for the in situ growth of functionalized carbon nanofibers, resulting in a favorable architecture of an Ni₂P well-integrated carbon matrix. With this unique structure, the resultant Ni₂P@NPCNFs electrode shows remarkable Li-ion storage performance, in terms of high reversible capacity and long-cyclic lifespan (850 mAh g^-1 at 200 mA g^-1 after 450 cycles), as well as a good rate behavior (300 mAh g^-1 at 3200 mA g^-1). This work not only presents a new avenue to construct advanced Ni₂P-based functional nanocomposites for Li-ion batteries but also paves the way to explore unique transition-metal phosphides toward diverse applications.