Highly porous carbon aerogel-based cathode for high energy Lithium - Sulphur batteries

Abstract

Lithium -sulfur batteries (Li-S) are among the most promising candidates for alternative energy storage systems due to their high theoretical gravimetric energy density of up to 2600 Wh/kg. Despite the advantages of the Li-S battery, sulfur-based cathodes still pose challenges such as a limited accessibility of sulfur, significant volumetric changes during the electrochemical reaction and a high solubility of polysulfide intermediates in the electrolyte. To address these challenges, novel aerogel-based cathode materials were developed. Carbon aerogels (CAs), produced by carbonization of elastically deformable organic aerogels, exhibit tunable and porous structures (porosities up to 97%), high surface areas (500-3500 m²/g), large pore volumes (0.1-2.5 cm³/g), and significant electrical conductivities (80-150 S/m). Their microstructures are adjustable by the synthesis of organic aerogels and subsequent carbonization. Moreover, the elastic compressibility of CAs prevents the formation of cracks as a result of changes to the sulfur volume.