Energy-efficient and resource-conserving water management can make an important contribution to the energy transition in the future. The microbial fuel cell (MBC) plays a key role in this.

The MBC uses the chemically bound energy in the wastewater to convert it directly into electricity, while at the same time purifying the wastewater. Exoelectrogenic microorganisms metabolize the organic substrates present on the anode side, thereby releasing electrons. These reach the cathode via an external circuit, where oxygen reduction takes place. It is already known from the literature and from our own experience in the previous project that the cathode is the limiting component of an MBC due to its low electrochemical performance. Current investigations are therefore focusing on suitable cathode designs, improved manufacturing processes and their scalability. Within the DEMO-BioBZ project, the scale-up of the catalytic coating of gas diffusion electrodes for use in a MBZ is therefore being investigated.

The ICVT working group is initially researching the development of a suitable suspension based on inorganic catalysts. Different formulations are applied to initially small electrode surfaces by means of spray coating and evaluated. The electrodes are evaluated using electrochemical and physico-chemical characterization methods. A coating system is being developed and set up for a scalable, uniform coating of the electrodes. The long-term goal is the production of gas diffusion electrodes with a surface area of one square meter and their use in a demonstration plant to evaluate the function of an MBZ.