Last March Annemerel Mol won the UFW-KLV thesis award for her master thesis ‘Bio-electro chemical battery’ in the category Environmental Sciences. This prize is awarded every year by University Fund Wageningen and by KLV Alumni Network Wageningen to outstanding students that have been graded with a 9 or higher for their M.Sc. thesis.
The jury was clearly impressed by Mol’s work, that they described as ‘a highly accessible and entirely convincing thesis’. Not only did she provide proof of concept of a bio-electrochemical battery, but also developed a working prototype based on an original, theoretical and practical approach. According to the jury, Mol’s thesis is a first step towards an environmental friendly, renewable electricity storage system that has the potential to be competitive with existing polluting battery systems.
Current electricity-storing systems, like lithium-ion batteries, are expensive, contain rare materials and are difficult to recycle. Therefore, there is a growing need for cost-effective, environmental friendly technologies to store surplus electricity from renewable resources, like wind or solar energy. The newly developed bio-battery is definitely an excellent candidate. Mol: ‘Our bio-battery is made exclusively from materials that are widely available and is completely biodegradable.
Micro-organisms play a key role in the concept of the bio-battery. The principle is based on the exchange of electrical and chemical energy. The design consists of 2 main components, a charging unit and a discharging unit, that are integrated in one system. To charge the battery, bacteria convert CO2 and electrical energy (electrons), supplied by a sustainable resource, into acetic acid. The battery is discharged and delivers energy when different bacteria convert acetic acid (chemical energy) back into CO2 and electrons (fig. 1). ‘It was a lot of hard precision work and determination to integrate these systems’, says the prize winner. ‘But in the end it all worked out and we built a functioning battery!’