α-MnO₂ Nanowire Catalysts with Ultra-High Capacity and Extremely Low Overpotential in Lithium-Air Batteries through Tailored Surface Arrangement

We here report on very high capacity (11000 mA h g⁻¹), superb rate capability (4500 mA h g⁻¹ at 5000 mA g⁻¹) and high reversibility of Li-air batteries using α-MnO₂ NW catalysts mainly associated with their relatively large amount of Mn³⁺ exposed on the NW surface and a unique mechanism for deposition of discharge products. Our findings of the unprecedentedly fast Li-ion transport and reversible formation-decomposition of discharge products attributed to the modified surface arrangement of α-MnO₂ NWs suggest a strategy for achieving high-power Li-air batteries in combination with nano-architecture tailoring.