Anti-deformation evaluation and optimization of a carbon cloth-based self-pumping microfluidic fuel cell

Abstract

It is crucial to evaluate the deformation resistance and optimize the structure of passive microfluidic fuel cells, which are susceptible to deformation during practical applications. Therefore, a three-dimensional model of a carbon cloth-based self-pumping microfluidic fuel cell is proposed in this study, which includes both steady-state and transient analyses. The physical fields used include the Brinkman equation, secondary current distribution, dilute matter transfer in porous media, etc. After validation of both steady-state and transient models, the overall twist angle, longitudinal folding angle and transverse folding angle are varied to assess the anti-deformation ability. And then, the absorbent pad shape and the thickness of the carbon cloth electrode are also studied to improve the cell performance. The results demonstrate that the electrode overpotential is 1.2 V when using 2 M HCOONa as fuel. It exhibited the best performance when the thickness is 0.024 cm, corresponding to a cut-off current density of 34.91 mA/cm2, a maximum power density of 10.46 mW/cm2 and a fuel utilization rate of 6.78%. In particular, transient studies indicate that the cell can maintain a current density value above 4.95 mA/cm2 for 3000 s.