Computational modeling of air-breathing microfluidic fuel cells with flow-over and flow-through anodes

Abstract A three-dimensional computational model for air-breathing microfluidic fuel cells (AMFCs) with flow-over and flow-through anodes is developed. The coupled multiphysics phenomena of fluid flow, species transport and electrochemical reactions are resolved numerically. The model has been validated against experimental data using an in-house AMFC prototype with a flow-through anode. Characteristics of fuel transfer and fuel crossover for both types of anodes are investigated. The model results reveal that the fuel transport to the flow-over anode is intrinsically limited by the fuel concentration boundary layer. Conversely, fuel transport for the flow-through anode is convectively enhanced by the permeate flow, and no concentration boundary layer is observed. An unexpected additional advantage of the flow-through anode configuration is lower parasitic (crossover) current density than the flow-over case at practical low flow rates. Cell performance of the flow-through case is found to be limited by reaction kinetics. The present model provides insights into the fuel transport and fuel crossover in air-breathing microfluidic fuel cells and provides guidance for further design and operation optimization.

[1]  Jian Shi,et al.  Characterization of microfluidic fuel cell based on multiple laminar flow , 2007 .

[2]  Jon G. Pharoah,et al.  Computational analysis of heat and mass transfer in a micro-structured PEMFC cathode , 2006 .

[3]  Dennis Y.C. Leung,et al.  Hydrodynamic focusing in microfluidic membraneless fuel cells: Breaking the trade-off between fuel u , 2011 .

[4]  Mina Hoorfar,et al.  Numerical study of the effect of the channel and electrode geometry on the performance of microfluidic fuel cells , 2010 .

[5]  David Sinton,et al.  An alkaline microfluidic fuel cell based on formate and hypochlorite bleach , 2008 .

[6]  Erik Kjeang,et al.  Computational modeling of microfluidic fuel cells with flow-through porous electrodes , 2011 .

[7]  Héctor D. Abruña,et al.  Fabrication and preliminary testing of a planar membraneless microchannel fuel cell , 2005 .

[8]  David Sinton,et al.  Improved fuel utilization in microfluidic fuel cells: A computational study , 2005 .

[9]  Larry J. Markoski,et al.  Microfluidic fuel cell based on laminar flow , 2004 .

[10]  Hong Xu,et al.  Enabling high-concentrated fuel operation of fuel cells with microfluidic principles: A feasibility study , 2013 .

[11]  Min-Hsing Chang,et al.  Analysis of membraneless fuel cell using laminar flow in a Y-shaped microchannel , 2006 .

[12]  K. Sundmacher,et al.  Understanding the dynamic behaviour of direct methanol fuel cells: Response to step changes in cell current , 2007 .

[13]  Jonathan D. Posner,et al.  Sequential Flow Membraneless Microfluidic Fuel Cell with Porous Electrodes , 2008 .

[14]  Nam-Trung Nguyen,et al.  Air-breathing membraneless laminar flow-based fuel cell with flow-through anode , 2012 .

[15]  Ned Djilali,et al.  Mathematical modelling of ambient air-breathing fuel cells for portable devices , 2007 .

[16]  Kenta Kishi,et al.  Electricity Generation from Decomposition of Hydrogen Peroxide , 2005 .

[17]  Paul J A Kenis,et al.  Air-breathing laminar flow-based microfluidic fuel cell. , 2005, Journal of the American Chemical Society.

[18]  David Sinton,et al.  Microfluidic fuel cells: A review , 2009 .

[19]  Ville Saarinen,et al.  A 3D model for the free-breathing direct methanol fuel cell: Methanol crossover aspects and validations with current distribution measurements , 2007 .

[20]  David Sinton,et al.  Hydrogen Peroxide as an Oxidant for Microfluidic Fuel Cells , 2007 .

[21]  Nam-Trung Nguyen,et al.  Air-breathing microfluidic fuel cell with fuel reservoir , 2012 .

[22]  Jun Li,et al.  Air-breathing direct formic acid microfluidic fuel cell with an array of cylinder anodes , 2014 .

[23]  Seong Kee Yoon,et al.  On the performance of membraneless laminar flow-based fuel cells , 2010 .

[24]  Mark W. Verbrugge,et al.  Ion and Solvent Transport in Ion‐Exchange Membranes I . A Macrohomogeneous Mathematical Model , 1990 .

[25]  Datong Song,et al.  Numerical optimization study of the catalyst layer of PEM fuel cell cathode , 2004 .

[26]  Dennis Y.C. Leung,et al.  Chaotic flow-based fuel cell built on counter-flow microfluidic network: Predicting the over-limitin , 2011 .

[27]  Nam-Trung Nguyen,et al.  An air-breathing microfluidic formic acid fuel cell with a porous planar anode: experimental and numerical investigations , 2010 .

[28]  E. U. Ubong,et al.  Three-Dimensional Modeling and Experimental Study of a High Temperature PBI-Based PEM Fuel Cell , 2009 .

[29]  Nam-Trung Nguyen,et al.  A review on membraneless laminar flow-based fuel cells , 2011 .

[30]  Paul J A Kenis,et al.  Microfluidic hydrogen fuel cell with a liquid electrolyte. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[31]  P. Kenis,et al.  Active control of the depletion boundary layers in microfluidic electrochemical reactors. , 2006, Lab on a chip.

[32]  David Sinton,et al.  A microfluidic fuel cell with flow-through porous electrodes. , 2008, Journal of the American Chemical Society.

[33]  Fikile R. Brushett,et al.  Alkaline Microfluidic Hydrogen-Oxygen Fuel Cell as a Cathode Characterization Platform , 2009 .

[34]  Min-Hsing Chang,et al.  Analysis of membraneless formic acid microfuel cell using a planar microchannel , 2007 .

[35]  Q. Liao,et al.  Two-dimensional two-phase mass transport model for methanol and water crossover in air-breathing direct methanol fuel cells , 2009 .

[36]  Dennis Y.C. Leung,et al.  Air-breathing membraneless laminar flow-based fuel cells: Do they breathe enough oxygen? , 2013 .