Extra Current Uncovered in Alkaline Biofuel Cells

Abstract

<p>p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 11.0px Times}</p> <p>Due to the environmental burden of fossil fuel combustion, a major strategic shift towards renewable green sources and environmentally benign power generation technology makes biofuel cells a possible alternative, though their extremely low current density remains a bottleneck for the further practical applications. Recent progress shows some promise to increase the current by platinum (Pt) electrodes, and alkaline solution to replace the enzymes/microbes. However, the approach involves high cost of noble metals as well as their poisoning effect. We report here a glucose biofuel cell based on nickel (Ni) electrodes and alkaline medium without the catalyst poisoning found in Pt systems. Surprisingly, a six-fold current increase over time, and a final current density equivalent to 1.5 times that of Pt have been achieved. They are found to be caused by the transformation of glucose to an enediol form, the expansion of triple phase boundaries where cathode reactions take place, and the enhancement of reaction kinetics by alkaline solution. The results not only provide a dramatic increase in current and overall biofuel cell performance, but also demonstrate a low cost approach to renewable source utilization, if corresponding designs can be implemented.</p>