Air-breathing batteries powered by the people
22 Apr 2013 by Evoluted New Media
Researchers in Poland have created air-breathing biobatteries that may be used to power pacemakers, hearing aids and other body implants in the future.
The team at the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw have developed an efficient electrode for use in biofuel cells or zinc-oxygen batteries. The batteries will use a special cathode that will work at full-efficiency when it takes oxygen directly from air.
“One of the most popular experiments in electrochemistry is to make a battery by sticking appropriately selected electrodes into a potato,” said Dr Jönsson-Niedzió?ka who led the research. “We are doing something similar, the difference is we’re focussing on biofuel cells and improving the cathode. And, of course, to have the whole project working, we’d rather replace the potato with… a human being.”
The IPC team’s zinc-air battery operates much like a traditional battery such as those used in hearing aids. These work with a zinc anode that gets oxidised, moving electrons across a circuit to a carbon cathode. But the difference with this technology is that the conventional cathode is replaced by what the IPC researchers call a biocathode.
The biocathode consist of a bilirubin oxidase enzyme core, wrapped in carbon nanotubules and encapsulated in a porous structure.
The enzymes reduce the oxygen in the air to produce a lot of power. The carbon nanotubes help transport the electrons, which in turn increases the power output.
The cathode would be implanted into a patient and when paired with the zinc-air battery could supply power with a voltage of 1.75 volts for up to 10 days from oxygen inside the patient.
However, the cell’s efficiency decreases with time, which is likely due to a gradual deactivation of the enzyme on the biocathode.
“Here not everything is dependent on us, but on the progress in biotechnology. The lifetime of biofuel cells with our biocathode could be significantly prolonged, if the enzyme regeneration processes are successfully developed,” said Jönsson-Niedzió?ka.
