Output Power of Miniature Bio Fuel Cell versus Anode and Cathode Material Type

The need for renewable fuel sources make it important to develop biofuel cells based on cyanobacteria. In the previous work we found out that among cyaqnobacteria strains Synechococcus was more effective than Anabaena, and maximum efficiency with hybrid carbon anode was ~2 mW/m
²
. In this work we tested a number of hybrid carbon anodes including carbon felt and carbon veil. After analyzing and testing all the types of carbon used, it was concluded that the highest power output of 10 mW/m2 was achieved using carbon felt as the anode. This can be explained by the fact that this material, in comparison with the others, has a large surface area to volume ratio and porosity, which is a favorable factor for the creation and growth of cyanobacterial biofilms. Having received the output power of one cell, a theoretical calculation was made of the power of the matrix of 8 cells under ideal conditions. This power was about 4 μW, which is 2.7 times higher than the power of one such cell. This calculation is theoretical, so it is likely that in practice, due to the unpredictability of living organisms, this power will be slightly different. The rationale for this is that connecting multiple biological devices can be much more difficult than connecting conventional batteries or supercapacitors, because there is the potential for significant performance degradation due to varying impedance mismatches between stored devices. The possible large voltage drop is mainly due to the uneven distribution of the performance of individual units and the subsequent voltage reversal from the less efficient cells.