Exploration of cobalt phosphate as a potential catalyst for rechargeable aqueous sodium-air battery

Bifunctional catalysts are prominent to attain high capacity, maximum energy efficiency and long cycle life for aqueous rechargeable Na-air batteries. In this work, we report the synthesis of bi-functional noble metal free, Co-3(PO4)(2) nanostructures by facile precipitation technique and evaluated its electrocatalytic activity. Co-3(PO4)(2) nanostructure was investigated as a potential electrocatalyst for rechargeable aqueous Na-air battery for the first time. The synthesized Co-3(PO4)(2) grain-like nanostructures showed better oxygen evolution activity compared to Pt/C catalyst. The fabricated Na-air battery with the Co-3(PO4)(2) catalyst as air-cathode delivered low overpotential and its round trip energy efficiency reached up to 83%. The Na-air battery exhibited stable cycle performance up to 50 cycles. (C) 2016 Elsevier B.V. All rights reserved.