Preparation and electrochemical properties of Na₃V₂(PO₄)₃/C cathode materials from spent electroless nickel plating bath

Abstract Through a sol-gel method, a honeycomb-like Na₃V₂(PO₄)₃/C cathode material for sodium-ion batteries was synthesized from a spent electroless nickel plating bath. The obtained Na₃V₂(PO₄)₃/C exhibited excellent electrochemical properties, with the initial discharge capacity of 108.3 mAh·g⁻¹ at 0.2 C and the capacity retention of 99.3% after 300 cycles, which was comparable to that of powders prepared from chemical reagents. This study will be helpful for the value-adding utilization of the spent electroless nickel plating bath.