Construction of nano Au-nitrogen doped carbon nanotubes integrated composite cathode and performance study for lithium-oxygen batteries

Highly efficient, stable cathode is crucial to lithium-oxygen battery. A high performance, integrated Au-N-CNT/SS cathode with interpermeable channels was constructed by chemical vapor deposition and photoreduction, in which the high catalytic Au nanoparticles were loaded on nitrogen doped carbon nanotubes with three-dimensional permeable of stainless steel mesh. The morphology and composition of the Au-N-CNT/SS were investigated by SEM, TEM, XPS, XRD and Raman spectrum. The problems of poor mechanical stability, carbonaceous cathode decomposition and serious side reactions were avoided by the suitable channel structure, high conductivity, superior mechanical properties, structural stability of Au-N-CNT/SS. Taking Au-N-CNT/SS as the integrated cathode for lithium-oxygen battery, the utilization of binder is avoided. The mechanical strength of the lithium-oxygen battery is enhanced, and the side reactions are effectively reduced, contributing to the enhanced electrochemical/chemical stability. The high conductivity, interpenetrated structure and sufficient pores provide a fast electron transport and mass transfer channel. The highly efficient Au nanoparticles are favorable to improving the oxygen reduction/oxygen evolution reaction kinetics on cathode, accelerating the generation and decomposition of discharge products. The rate performance (keeping the discharge voltage at 2.4 V with a high current density of 1.0 mA·cm⁻²), specific capacity (8.47 mA·h·cm⁻²) and cycle performance (160 cycles) of lithium-oxygen battery are greatly improved.