Biofuel cells are devices that generate portable electrical power, typically from glucose, alcohols or related biofuels, by using enzymatic anodes and cathodes. We report on the performance of membrane- and mediator-free enzymatic glucose biofuel cells (BFCs) fabricated in a sandwiched, patch geometry with carbon nanotube nanopaper bio-electrodes prepared using a compression technique to immobilize the enzymes. A gel electrolyte comprised of agar mixed with glucose is sandwiched between the two bio-electrodes to form a patch. Power densities up to 111.90 μW/cm2 at a current density of 334.50 μA/cm2 at a voltage of 0.335 V were obtained for a typical single cell BFC of this design. The sandwich BFC also showed good stability with a half-life of about 1.5 days under continuous operation. The relatively high power density for this new design is attributed to the compression-induced immobilization of the enzymes by the nanotubes as indicated by scanning electron microscope images. This compression-induced immobilization of enzymes provides improved direct electron transfer at the carbon nanotube electrodes.
All Science Journal Classification (ASJC) codes
- Materials Science(all)