Computational Facilitation of Large Scale Microfluidic Fuel Cell Architectures

Abstract

Hydrogen fuel cells are a key technology in the transition toward carbon-neutral energy systems, offering clean power with water as the only byproduct. Microfluidic fuel cells, which operate at the microliter scale, are an emerging variant that offer fine control over fluid and thermal dynamics, along with compact, efficient designs. However, scaling these systems to meet practical power demands remains a major challenge -- particularly due to the limitations of conventional simulation methods like Computational Fluid Dynamics (CFD), which are computationally expensive and scale poorly. In this work, we propose a reduced-order simulation method that models the behavior of individual microfluidic fuel cells and efficiently extends it to large scale stacks. This approach significantly reduces simulation time while maintaining close agreement with detailed CFD results. The method is validated, evaluated for scalability, and discussed in the context of ongoing advancements in microfluidic fuel cell fabrication. The obtained results demonstrate that this abstraction can support the design and development of scalable microfluidic fuel cell systems and, for the first time, the consideration of first macroscale instances of practical value.

Figures (12)

• Figure 1: A schematic representation of a conventional air-breathing fuel cell system. Besides the fuel cell, the system is composed of various subsystems, including: A fuel and air intake subsystem, a water removal subsystem, and thermal control subsystem.
• Figure 2: The polarization curve (black) is generally used to evaluate the performance of a fuel cell. The curve consists of three main losses: The overpotential loss, ohmic loss, and the mass transport loss. The power density curve (grey) follows from the polarization curve.
• Figure 3: Schematic representation of a single microfluidic fuel cell with opposing anode and cathode of length $L$. The concentration profile of hydrogen evolves as it flows through the channel.
• Figure 4: A microfluidic fuel cell stack can be separated into a flow network and an electrical network. The interface of these two networks is the set of fuel cells, which relate the operating current density with the fluid species concentrations, and vice versa. In each of these networks, the cells can be connected in serial, as well as parallel.
• Figure 5: The single cell channel used as validation case.