The (2 × 2) tunnels structured manganese dioxide nanorods with α phase for lithium air batteries

• The (2 × 2) tunnels structured α-MnO2 nanorods are prepared by a facile hydrothermal route.
• It is applied as electro-catalyst for cathode in rechargeable Li–O2 cells.
• Li–O2 cells exhibited initial discharge capacity as high as ∼4000 mAh/g.
• Obtained100% round trip cyclic efficiency for more than 50 cycles.

The (2 × 2) tunnels structured manganese dioxide nanorods with α phase (α-MnO2) are synthesized via simplistic hydrothermal method at low temperature. The obtained tunnels structured α–MnO2 nanorods are characterized by, Transmission electron microscopy, Scanning electron microscopy, and X-ray diffraction techniques. The oxygen reduction reaction (ORR) activity was studied by cyclic voltammetry and rotating ring-disc electrode voltammetry techniques in alkaline media. Moreover; the highly electrocatalytic tunnels structured α–MnO2 nanorods were then also applied as cathode in rechargeable Li–O2 cells. The Li–O2 cells exhibited initial discharge capacity as high as ∼4000 mAh/g with the tunnels structured α–MnO2 nanorods which was double the original capacity of the cells without any catalyst. Also we obtained 100% round trip efficiency upon cycling with limited capacity for more than 50 cycles.