Manganese and cobalt bimetallic-doped Prussian blue analogs as a bifunctional electrocatalyst for zinc-air batteries

Zinc-air battery is a novel safe and environment-friendly energy storage device, but the noble-metal electrocatalysts at the air electrode urge people to search for new substitutes. Herein, different ratios of manganese (Mn) and cobalt (Co) are doped into the iron Prussian blue analogs (PBAs) and used as bifunctional electrocatalysts. The Mn1.33Co0.67-PBA shows the outstanding electrocatalytic properties that the half-wave potential is 0.79 V, the Ej=10 of OER is 1.54 V, and the ΔE is as low as 0.75 V, which is superior to that of Pt/C + RuO2 system (0.78 V). Benefiting from the bimetallic-doping advantage, the Mn1.33Co0.67-PBA has good stability in alkaline solutions. Besides, the Mn1.33Co0.67-PBA was assembled into ZAB, possessing a high maximum power density of 161 mW cm-2 and a large specific capacity of 617 mAh g-1, as well as excellent cycle stability. The as-prepared bimetallic-doped PBA has the potential for applications in the energy storage and conversion field.