Geometric Design Optimisations Towards Improved Power Production Within Alkaline Carbohydrate Fuel Cells

Though direct carbohydrate fuel cells offer a highly efficient pathway from abundant, non-toxic sugars to electricity, currently their potential remains untapped due to a lack of knowledge of the impact of different cell geometries on their output power. In this work, simple modifications to the configuration of carbohydrate fuel cells are shown to significantly impact the performance of alkaline carbohydrate fuel cells. Increasing the density of a metal foam anode from 250 to 1000 mg cm was found to increase power output by up to ∼30%. These anode density changes also affected optimal fuel concentrations, which dropped from 1 M to 0.75 M. Decreasing the distance between electrodes from 20 mm to 6 mm resulted in improved maximum power outputs of ∼35%. Identifying these new loss mechanisms in this device type provides a basis to optimise alkaline carbohydrate fuel cell performance and provide insights that help reconcile some of the disparities observed throughout the research space.