Improving the Output of Biofuel Cells Using Lactic Acid Fuel by Using Two Anode Electrodes of LOD and LDH

An enzymatic biofuel cell (EBFC) that uses lactic acid as fuel to generate electricity is an attractive power source for wearable devices. Power density of an EBFC was improved by using two paired electrodes: LOD (anode)-BOD (cathode) and LDH+NAD (anode)-BOD (cathode). The purpose was to reduce the pyruvic acid produced by LOD at anode. The enzymes that generate power output were LOD at the anode and BOD at the cathode, and the additional electrode pair modified with LDH and NAD at the anode and BOD at the cathode was placed near the power output electrodes. The combination of LDH and NAD can perform both oxidation and reduction. Therefore, the pyruvic acid produced at the anode can be reduced. The output of the single pair electrodes (LOD-BOD) was increased from 25 μW/cm2 to approximately 43 μW/cm2 (1.7 times) with the additional paired electrodes.