European researchers develop bio-based hybrid fuel cell

In Germany, researchers have developed a hybrid of a fuel cell and capacitor on a biocatalytic basis. With the aid of enzymatic processes, what’s known as a biosupercapacitor efficiently generates and stores energy. The trick: the enzymes are embedded in a stable polymer gel, which can store a large amount of energy. The scientists at the Ruhr-Universität Bochum and the Swedish Malmö University describe their development in the journal Angewandte Chemie.

With the aid of an enzyme, the biosupercapacitor burns glucose as a fuel at one electrode. At the other electrode, an enzyme converts oxygen into water. Both enzymes must be embedded in an electron-conducting gel in order to establish the electrical contact to the electrodes. For the first time, the team used the same gel, also called a redox polymer, for both electrodes.

When charging up and storing the energy, this redox polymer at one electrode gives off electrons and is thus positively charged. At the other electrode, it takes in the electrons and is thus negatively charged.

The system set up in this manner showed itself to be stable in the researchers’ tests and can serve as a permanent source of energy. It has a low weight and a high capacity, so it can hold a large charge.