Biomass derived hierarchically porous carbon inherent structure as an effective metal free cathode for Li-O2/air battery.

A hierarchical porous carbon framework derived from betel-nut is synthesized and employed as a bifunctional cathode in a Li-O2/air battery. The prepared betel nut derived activated porous carbon (BNAPC) material exhibits an ordered and merged tube-like porous morphology and a high specific surface area of 768m²/g. The presence of both meso and micro porous leads to a well-developed 3D interconnected carbon framework, which provides an efficient path for the diffusion of the reactant (oxygen as well as air) and also allows stocking the discharge product of Li2O2. Therefore, it exhibits a high specific capacity and excellent rate performance. A maximum discharge capacity of 9560 and 2000 mAh/g at a current density of 100 mA/g for oxygen and ambient air respectively as the reactant is achieved. The prepared material also exhibits reversible cyclic stability of 27 cycles with a specific capacity of 1000 mAh/g at a 100 mA/g current density in oxygen atmosphere. [ABSTRACT FROM AUTHOR]