Mesoporous Co₃O₄-Rods-Entangled Carbonized Polyaniline Nanotubes as an Efficient Cathode Material toward Stable Lithium-Air Batteries

Lithium-air batteries (LABs) are considered as one of the most promising next-generation energy storage devices due to their high theoretic specific energy. However, the commercialization of current LABs is considerably limited by the high overpotential in charging/discharging, low energy efficiency, and poor cyclability. To solve these problems, mesoporous Co₃O₄-rods-entangled carbonized polyaniline nanotubes (Co₃O₄-e-cPANI) have been facilely prepared through a facile hydrothermal method, and their unique hierarchical architectures fully exploit synergistic effects from the catalytically active Co₃O₄ and the conductive cPANI, simultaneously facilitating the rapid oxygen diffusion and electrolyte penetration as well as unimpeded electron transportation. As a result, the LAB with the Co₃O₄-e-cPANI cathode shows an excellent cycling stability of 430 cycles under a reversible capacity of 500 mAh g^-1 and 226 cycles under a higher capacity of 1000 mAh g^-1. The current results demonstrate that optimizing the air cathode structure such as constructing Co₃O₄-e-cPANI architecture is an important route to further improve the stability of LABs toward practical applications.