A membraneless microfluidic fuel cell with a hollow flow channel and porous flow‐through electrodes

Abstract

A novel flow channel configuration of a membraneless microfluidic fuel cell (MMFC) with porous flow-through electrodes was investigated numerically. A numerical model was developed for the electrochemical analysis and validated using experimental data. The physical phenomena involved in the microfluidic fuel cell including the flow of the vanadium redox couple (oxidant and fuel), mass transport, and electrochemical reaction kinetics at the electrodes are coupled in the numerical model. Considering the impact of diffusive mixing zone on the performance of MMFC, a hollow structure is proposed for the cross-section of the central flow channel. The hollow structure showed a peak power density, which is higher than those of the H-shaped, simple bridgeshaped, and rectangular channels by 6%, 18%, and 82%, respectively. Highlights• Numerical model of an MMFC with flow-through porous electrodes was validated using experimental data.• MMFC with flow through electrodes was investigated for various channel configurations.• Hollow flow channel coupled with porous electrodes performed best at critical height ratio.

Microfluidics for Electrochemical Energy Conversion

“…When paired with reactant chemistries with rapid kinetics, the cells with flow-through configuration are therefore often limited by ohmic losses. The flow-through porous electrode configuration has been widely applied in μFCs since then and enabled high power density outputs. ,,,− The flow-through configuration has also been applied with metal-foam electrodes or metal meshes. , Additionally, zinc metal was demonstrated to be electrodeposited on the pore structure of the porous carbon, which would be electrochemically stripped during discharge . Overall, the highest power density performance reported to date by Goulet et al, of 2.0 W/cm 2 , was achieved by the application of in operando flowing deposition on flow-through porous electrodes to concurrently increase active surface area and local mass transport combined with current collectors and cell design optimization to reduce ohmic losses (Figure e).…”

Advances in microfluidic electrochemical fuel cells in recent years

“…Performance decrease always occurred with raised channel width, height and length, and the model revealed that the inlet in the center of the channel and multicompartment were able to augment the cell performance. The researchers investigated the impact of channel configuration on the performance of MFEFCs by a novel numerical model 114 . A hollow flow channel was introduced for better performance.…”

“…The researchers investigated the impact of channel configuration on the performance of MFEFCs by a novel numerical model. 114 A hollow flow channel was introduced for better performance. After multiple numerical simulations and experiments, it was validated that performance of the hollow flow channel was better than the H-shaped, bridge-shaped and rectangular channels.…”

Optimal design of reactant delivery system in microfluidic fuel cell with porous electrodes

“…A series of studies have been performed to further ameliorate the design of flow-through type MFC including synthesis of advanced porous electrode material, [25][26][27][28] optimization of electrode geometry and configuration, 29,30 introduction of novel cell architectures [31][32][33] and construction of MFC stacks. 34,35 Yet, reactant delivery systems with different shaped inlet reservoirs are commonly reserved.…”