Hydrodynamic focusing in microfluidic membraneless fuel cells: Breaking the trade-off between fuel utilization and current density

Jin Xuan, Michael K H Leung, Dennis Y C Leung, Meng Ni, Huizhi Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

24 Citations (Scopus)

Abstract

Microfluidic membraneless fuel cell (MFC) is a promising fuel cell type due to its simple structure without the need of proton conducting membrane. However, the common disadvantage is the low fuel utilization. Previous works have shown that adopting a conventional method to increase the fuel utilization would cause a low power density. This study shows that the use of hydrodynamic focusing technology can overcome the trade-off problem between the fuel utilization and the current density. A numerical model has been developed to simulate the MFC operation with the fuel stream being hydrodynamically focused by a buffer stream. The results indicate that both fuel utilization and current density can be increased by properly adjusting the buffer flow rate to enhance the flow focusing. The optimal performance is achieved when the buffer-to-fuel flow rate ratio is around 25. Moreover, high fuel flow rate and shallow channel shape have proven beneficial to the cell performance with the use of hydrodynamic focusing technology. It is predicted that a MFC with a current density above 100 mA cm-2is capable of achieving fuel utilization up to 50%, which is considerably higher than the previously reported value of 5-8%.
Original languageEnglish
Pages (from-to)11075-11084
Number of pages10
JournalInternational Journal of Hydrogen Energy
Volume36
Issue number17
DOIs
Publication statusPublished - 1 Aug 2011

Keywords

  • Computational fluid dynamics
  • Current density
  • Fuel utilization
  • Hydrodynamic focusing
  • Microfluidics

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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