Graphene aerogel sponge promises battery boost

Developed at Chalmers University of Technology in Gothenburg, the prototype consists of slices of porous graphene oxide aerogel in a cell battery that soak up a sulphur-rich ‘catholyte’ solution. This catholyte acts as cathode and electrolyte, interacting with a lithium anode via a separator layer within the cell. The concept helps save weight and can deliver faster charging and better power output.

“You take the aerogel, which is a long thin tube, and then you slice it – almost like a salami,” said Carmen Cavallo, lead researcher on the study, which appears in the Journal of Power Sources.  “You take that slice, and compress it, to fit into the battery.”

The sulphur-rich catholyte solution is then added, with the highly porous aerogel acting as the support, soaking up the liquid like a sponge.

“The porous structure of the graphene aerogel is key,” Cavallo continued.  “It soaks up a high amount of the catholyte, giving you high enough sulphur loading to make the catholyte concept worthwhile. This kind of semi-liquid catholyte is really essential here. It allows the sulphur to cycle back and forth without any losses. It is not lost through dissolution – because it is already dissolved into the catholyte solution.”