Application of functionalized carbon nanotubes as the cathode of nonaqueous lithium-oxygen cells

Lithium-oxygen cells have attracted the significant attention of researchers in recent years due to their extremely high energy density, comparable to the energy density of fossil fuels. However, because of the sluggish kinetics of discharge/charge reactions, the development of lithium-oxygen technology has been largely limited. One way to tackle this problem is the development of an efficient catalyst for cathode materials that will exhibit high ca-pacities, good rate capabilities, and sufficient stability. Due to their excellent electrochemical properties and controlled porous texture, carbon nanotubes (CNTs) have been one of the candidates for this application. Many methods have been proposed to improve their catalytic activity and, as a result, enhance the performance of lithium-oxygen cells. These include transition metal coating, precious metal decorating, or heteroatom doping. This review provides an in-depth look at CNT functionalization methods and their impact on nonaqueous lith-ium-oxygen cell performance.