In-situ preparation and unique electrochemical behavior of pore-embedding CoO/Co3O4 intermixed composite for Li+ rechargeable battery electrodes

Electrochemically active CoO/Co3O4 co-existing microspheres with morphology-inherited porous particles is successfully synthesized via a simple solvothermal method. The as-prepared intermixed composite undergoes a monoxide CoO-preferred conversion reaction with an extremely enhanced capacity retention, ∼905 mA h g−1 after 250 cycles for discharge state, which is 1.6 times higher than the conventional CoOx-based anodes. Moreover, stable catalytic behavior of the electrocatalysts in Li-air cathodes of the given composites is also demonstrated. We believe that the extraordinarily enhanced electrode performance might be due to the novel pore-tempered microspheres packed with double electrochemically active centers of the CoO/Co3O4 composite effectively confine the detrimental volume exchange during the reversible cyclic reactions as well as the preserved multiple reactive sites for a reversible Li+ ⇄ LiOx reaction, which is advantageous for advanced Li rechargeable battery.