The battery combined two technologies. The first is that of a microbial fuel cell in which electricity is produced when electrons are lost by one molecule and gained by another as they undergo an reduction/oxidation (redox) reaction. The second is microbial electrosynthesis, a process in which the electricity produced is converted back into chemicals be be reused in the battery.
In their trials of the battery, which were reported in Environmental Science & Technology Letters, the researchers allowed the battery to charge for 16 hours and then were able to get eight hours of power from it, which mimics the behavior of current solar cells.
The creators of the battery, Sam D. Molenaar, and his colleagues from Wageningen University and Wetsus in the Netherlands believe that, with further optimization, the bacteria-based battery could rival the performance of lithium-ion batteries at a lower cost and with greater safety. One possible application of the batteries would be to store energy from renewable sources such as solar and wind.