Highly hierarchical porous structures constructed from NiO nanosheets act as Li ion and O pathways in long cycle life, rechargeable Li-O batteries.

Flower-like NiO with a highly hierarchical porous structure was synthesized and used as a cathode material for Li-O batteries. The disordered porous structure and specific pathways for O and Li ions led to an outstanding cycling performance over 80 cycles at a high current density of 200 mA g.