Abstract:

In this study, a theoretical analysis for a novel microfluidic vanadium fuel cell was implemented, which relies on laminar flow at low Reynolds number to maintain sufficient separation of fuel and oxidant streams.A three-dimensional numerical model that accounts for laminar flow, transport process of species and electrochemical reactions in fuel cell, was developed to evaluate the effect of some important physical factors including volumetric flow rate and fuel purity.All coupled equations in the model were solved digitally together.The simulation results showed that output power and current density went up with the increase of flow rate, however, the fuel utilization went down significantly.As the volumetric flow rate increased from 1 μl·s^-1 to 25 μl·s^-1, the power density increased by 2.2 times and there was a 90% drop in fuel utilization.Further microfluidic fuel cell design and optimizations were guided by using the model, a double Y-shaped microchannel design is proposed.It is found that the fuel utilization can be improved significantly by using a double Y-shaped microchannel.