Scale up of single-chamber microbial fuel cells with stainless steel 3D anode: Effect of electrode surface areas and electrode spacing

Single-chamber microbial fuel cells (MFCs) with air-cathodes and new anodes made of stainless steel entangled wires are developed. Increasing the cathode surface area significantly increases performances (doubling the cathode surface area increases the maximum power by +23,3 % and tripling it by +59,8 %). By contrast, increasing the anode surface area rapidly leads to performance saturation (doubling the anode surface area increases the maximum power by +37.8 % but tripling it by only +39.3 %). In addition, decreasing the electrode spacing from 6 cm to 4 cm improves the maximum power by +21.3 % and from 4 cm to 2 cm by +27.9 %. This results permit to optimally dimension the architecture of the MFC in order to maximize energy production while minimizing the amount of materials used to minimize costs. This in turn is likely to enable the development of effective solutions for energy harvesting.