High sulfur loaded carbon aerogel cathode for lithium-sulfur batteries

An attempt made to improve sulfur loading in a template-free porous carbon to the extent of 70 wt% has led to two interesting observations being inferred, viz., 60 wt% sulfur loading exhibits superior electrochemical properties in the S@C composite form and an enhanced 73 wt% sulfur loading leads to the formation-cum-stabilisation of sulfur in its monoclinic phase. Carbon aerogel with tunable properties, derived from the catalyst-aided cross linking of resorcinol and formaldehyde, possessing a specific surface area of 1395 m(2) g(-1) and pore volume of 1.423 cm(3) g(-1) has been exploited for sulfur loading to form a series of S@C composites. Interestingly, carbon aerogel prepared in the present study offers multifarious advantages such as conducting additive, potential host to accommodate higher concentrations of sulfur and better polysulfide confining matrix. The 60 wt% sulfur loaded carbon aerogel composite exhibits an appreciable specific capacity of 600 mA h g(-1) at a C/10 rate up to 100 cycles, 480 mA h g(-1) at a 1C and 422 mA h g(-1) at a 2C rate. Hence, the capability of carbon aerogel, synthesized through the present study in accommodating higher concentrations of sulfur, effective management of polysulfide shuttle, and provision of favorable electrode-electrolyte interface to facilitate extended cycling possibilities at different current densities has been demonstrated.