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.