Stanford scientists are harnessing nanotechnology to quickly produce ultra-lightweight, bendable batteries and supercapacitors in the form of everyday paper. Simply coating a sheet of paper with ink made of single-walled carbon nanotube (CNT) and silver nanowire films makes a highly conductive storage device, said Yi Cui, assistant professor of materials science and engineering at Stanford University.
The paper storage-device can last through 40,000 charge-discharge cycles – at least an order of magnitude more than lithium batteries.
The commercially available paper can be made highly conductive with a sheet resistance as low as one ohm per square (Ω/sq), and when only the mass of the CNTs are considered, a specific capacitance of 200F/g, a specific energy of 30-47Wh/kg, and a specific power of 200,000W/kg can be achieved.
Cui had previously created nanomaterial energy-storage devices using plastics. His new research shows that a paper storage-device is more durable because the ink adheres more strongly to paper.
A paper storage-device may be especially useful for applications such as electric or hybrid cars, which depend on the quick transfer of electricity.
‘This technology has the potential to be commercialised within a short time,’ said Peidong Yang, professor of chemistry at the University of California-Berkeley.
‘I don’t think it will be limited to just energy storage devices.
‘This is potentially a very nice, low-cost flexible electrode for any electrical device.
Cui’s research team includes postdoctoral scholars Liangbing Hu and JangWook Choi, and graduate student Yuan Yang.