Flexible graphene foam may power wearable devices

Last month, researchers at Rice University in Texas unveiled a method for making three-dimensional forms made of foamed graphene. The Glasgow team, working independently, used a commercially available graphene foam to make a layered structure with a silver-containing epoxy resin to form supercapacitors capable of storing three times as much power as any similar flexible supercapacitor, they claim.

In a paper in the journal Nano Energy, the team from Glasgow's bendable electronics and sensing technologies (BEST) group, led by Prof Ravinder Dahiya, said that lithium ion batteries may not be suitable for wearable devices because they are inflexible and heavy and their heat may cause injuries. Supercapacitors, which charge and discharge quickly and can be made from more environmentally friendly materials, may be a more promising option, they said.

Dahiya’s team is exploring the emerging technology of hybrid supercapacitor/batteries. These are more stable than traditional supercapacitors, they said, and capable of operating over more than a million charge-discharge cycles without loss of performance.