"One of the most popular experiments in electrochemistry is to make a battery by sticking appropriately selected electrodes into a potato. We are doing something similar, the difference is that we are focusing on biofuel cells and the improvement of the cathode. And, of course, to have the whole project working, we'd rather replace the potato with... a human being", says Dr Martin Jnsson-Niedziłka (IPC PAS).
In the experiments, Dr Jnsson-Niedziłka's group uses zinc-oxygen batteries. The principle of their operation is not new. The batteries constructed in this way had been popular before the time of alkaline power sources came. "At present, many laboratories work on glucose-oxygen biofuel cells. In the best case they generate a voltage of 0.6-0.7 V. A zinc-oxygen biobattery with our cathode is able to generate 1.75 V for many hours.", says Adrianna Złoczewska, a PhD student at the IPC PAS, whose research has been supported under the International PhD Projects Programme of the Foundation for Polish Science.
The main component of the biocathode developed at the IPC PAS is an enzyme surrounded by carbon nanotubes and encapsulated in a porous structure a silicate matrix deposited on an oxygen permeable membrane. "Our group had been working for many years on techniques that were necessary to construct the cathode using enzymes, carbon nanotubes and silicate matrices", stresses Prof. Marcin Opałło (IPC PAS).
An electrode so constructed is installed in a wall of a small container. To have the biofuel cell working, it is enough to pour an electrolyte (here: a solution containing hydrogen ions) and insert the zinc electrode in the electrolyte. The pores in the silicate matrix enable oxygen supply from the air and H+ ions from the solution to active centres of the enzyme, where oxygen reduction
|Contact: Marcin Opallo|
Institute of Physical Chemistry of the Polish Academy of Sciences