Mesoporous CuCo₂O₄ nanoparticles as an efficient cathode catalyst for Li-O₂ batteries

Extremely high energy density and environment friendly reaction make Li-O₂ batteries a promising energy storage system. In order to improve the energy efficiency and cycle life of Li-O₂ battery, spinel mesoporous CuCo₂O₄ was successfully synthesized by a facile hydrothermal method and investigated in Li-O₂ batteries. The electrochemical measurements show that mesoporous CuCo₂O₄ possess higher oxygen reduction and oxygen evolution activity than bulk CuCo₂O₄ both in alkaline and non-aqueous solution. Owing to the inherent catalytic activity, high conductivity and facile mass transfer of mesoporous CuCo₂O₄, Li-O₂ battery shows enhanced electrochemical performances, including much lower charge overpotential and a high capacity up to 5288 mAh g^-1. When restricting the discharge capacity at 500 mAh g^-1, it could operate over 80 cycles and exhibit superior cycle stability. These results indicate that mesoporous CuCo₂O₄ nanoparticles are appropriate bifunctional catalysts for Li-O₂ batteries.