A novel anode-sharing configuration to enhance the volumetric power density of short stack of proton exchange membrane fuel cells: An experimental and numerical simulation study

Abstract

One goal for developing proton exchange membrane fuel cells is to increase the volumetric power density, enabling them to compete with internal combustion engines. Hence, this work proposes a novel anode-sharing configuration for a two-unit short stack of proton exchange membrane fuel cells, which effectively decreases the volume of the stack by utilizing one anode gas channel to supply hydrogen to both units. The feasibility and optimal operating conditions of this novel configuration have been validated by experiments. Three-dimensional numerical simulations reveal that alterations in stack configuration do not influence the distribution of reactants. Yet, the temperature in the anode-sharing short stack is relatively high due to the accumulated heat in the shared anode without cooling, which may cause membrane dehydration and affect overall performance. These negative effects can be offset by increasing relative humidity. Moreover, the thermal management can be significantly improved by enhancing cooling of the cathode when scaling up. A six-unit anode-sharing stack equipped with an enhanced cooling flow field has reduced the volume by 33.3 % and increased the volumetric power density by 40 %. The anode-sharing stack can achieve a volumetric power density up to 7 kW/L, a step closer to that of the internal combustion engines.