An Enhanced High-Rate Na₃V₂(PO₄)₃-Ni₂P Nanocomposite Cathode with Stable Lifetime for Sodium-Ion Batteries

Herein, we report on a high-discharge-rate Na₃V₂(PO₄)₃-Ni₂P/C (NVP-NP/C) composite cathode prepared using a polyol-based pyro synthesis for Na-ion battery applications. X-ray diffraction and electron microscopy studies established the presence of Na₃V₂(PO₄)₃ and Ni₂P, respectively, in the NVP-NP/C composite. As a cathode material, the obtained NVP-NP/C composite electrode exhibits higher discharge capacities (100.8 mAhg^-1 at 10.8 C and 73.9 mAhg^-1 at 34 C) than the NVP/C counterpart electrode (62.7 mAhg^-1 at 10.8 C and 4.7 mAhg^-1 at 34 C), and the composite electrode retained 95.3% of the initial capacity even after 1500 cycles at 16 C. The enhanced performance could be attributed to the synergetic effect of the Ni₂P phase and nanoscale NVP particles, which ultimately results in noticeably enhancing the electrical conductivity of the composite. The present study thus demonstrates that the Na₃V₂(PO₄)₃-Ni₂P/C nanocomposite is a prospective candidate for NIB with a high power/energy density.