3D Hollow α-MnO 2 Framework as an Efficient Electrocatalyst for Lithium-Oxygen Batteries

Lithium-oxygen (Li-O ) batteries are attracting more attention owing to their superior theoretical energy density compared to conventional Li-ion battery systems. With regards to the catalytically electrochemical reaction on a cathode, the electrocatalyst plays a key role in determining the performance of Li-O batteries. Herein, a new 3D hollow α-MnO framework (3D α-MnO ) with porous wall assembled by hierarchical α-MnO nanowires is prepared by a template-induced hydrothermal reaction and subsequent annealing treatment. Such a distinctive structure provides some essential properties for Li-O batteries including the intrinsic high catalytic activity of α-MnO , more catalytic active sites of hierarchical α-MnO nanowires on 3D framework, continuous hollow network and rich porosity for the storage of discharge product aggregations, and oxygen diffusion. As a consequence, 3D α-MnO achieves a high specific capacity of 8583 mA h g at a current density of 100 mA g , a superior rate capacity of 6311 mA h g at 300 mA g , and a very good cycling stability of 170 cycles at a current density of 200 mA g with a fixed capacity of 1000 mA h g . Importantly, the presented design strategy of 3D hollow framework in this work could be extended to other catalytic cathode design for Li-O batteries.