Research on the effect of catalyst structure on an air-breathing microfluidic fuel cell with crevice

ABSTRACT

The microfluidic fuel cell (MFC) takes advantages of small volume, portable structure, sustainable operation, and no pollution, making them provide a promising application prospect in miniaturized electronic devices. However, the poor output power density and low fuel utilization limit their practical applications. To address these issues, a novel design of dual-cell MFC with crevices has been proposed to alleviate the ionic resistance and improve the fuel utilization and output power density. In this paper, the constructed numerical model is validated by comparing with reported experimental data. The MFC with 0.1 mm crevice achieves the maximum power density of 77.2 W m⁻² and maximum fuel efficiency of 17.32%, which also can economize cathode catalyst material. The optimal flow velocity of 1 mL min⁻¹ is obtained, which demonstrates the maximum power density of 180.6 W m⁻² and maximum current density of 897.4 A m⁻². A large fuel concentration is beneficial to improve the MFC power density but is adverse to the fuel efficiency. The research results are helpful to reveal the underlying mechanisms of convection–diffusion–reaction process in MFC, which may provide significant theoretical suggestions for the practical applications.

KEYWORDS:

• Microfluidic fuel cell
• crevice width
• asymmetric catalyst structure
• numerical simulation
• operation condition

Nomenclature

C	=	Concentration, M
D	=	Diffusivity, m2 s−1
I	=	Exchange current density, A m−2
K	=	Permeability, m2
u	=	Inlet flow, mL min−1
p	=	Gas mixture pressure, atm
T	=	Temperature, K
Greek Letters	=
ρ	=	density, kg m3
µ	=	dynamic viscosity, Pa·s
σ	=	conductivity, S m1
ε	=	porosity
Subscripts	=
s	=	electrode
I	=	electrolyte

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work is supported by the National Natural Science Foundation of China [Grant No. 52106105], the China Postdoctoral Science Foundation [2021M702431], and the Natural Science Foundation of Tianjin (China) for Distinguished Young Scholars [Grant No. 18JCJQJC46700].