Rapid Screening of Micro Fuel Cells for Portable Electronics

1
Rapid Screening of Micro Fuel Cells for Portable
Electronics

• PIs Li Tan, Engineering Mechanics
• Zhaoyan Zhang, Mechanical Engineering
• University of Nebraska, Lincoln, NE

10/01/07
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Research Progress(11/01/06-09/30/07)

• 11/01/06-04/30/07 (also seen in previous report)
• Completed geometry and width design for
  micrometer channels
• Started modeling aspects of micro fuel cells
• Completed fabrication of individual channels with
  photolithography
• Completed fabrication of micro fuel cell testing
  array
• Completed fabrication of a testing sample with 4
  cells.
• 05/01/07-09/30/07
• Fabrication of micro fuel cell arrays
• Completed design of micro fuel cell arrays (8?8
  cells)
• Completed design/fabrication of three masks for
  micro channels, inlet/outlet, and electrodes
• Completed fabrication of micro channel arrays
  (4?4 cells) on Pyrex glass (1/4 wafer)
• Completed fabrication of inlet/outlet on Pyrex.
• Performance of Single Fuel Cell
• Two different electrolyte membranes (Nafion 117
  and 202) were explored.
• A novel concept on electrocatalyst support
• Initiated a methodology to integrate
  nanoparticles into fuel cell research.

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Completed 8?8 Fuel Cell Masks
Mask I in/outlets
Mask II Flow Channels
Fabricated In/outlets
Mask III Electrodes
Channel 3
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Completed Fuel Cell Array (4?4)
Photoresist
photoresist
Au
Cr
Au etching
Chromium/Gold
Cr etching
HF etching
Remove photoresist and Au/Cr
4.8 49 wt HF etching
Fuel Cell Array Fabrication Process Flow
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Experimental Measurements of Single Fuel Cell

• 2?2 array was used as a base for fuel cell
• Two conducting membranes with different
  thicknesses were tested
• Nafion 117 183?m
• Nafion 212 51?m
• Nafion 212 presented better efficiency, as
  expected due to its thinner nature.

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A Novel Electrocatalyst Support
Nanoparticle (0 dimension)
MicroFiber (1 dimension)
Packed Particles (80 nm)
Uniform ?1.5 ?m Fiber
Motivation The surface areas of current catalyst
supports are low, challenging to improve the fuel
cell performance. Aim 3D nanoporous catalyst
support.
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Summary and Future Work

• Confirmed (05/01/07-09/30/07)
• Fabrication of micro fuel cell arrays
• Completed design of micro fuel cell arrays (8?8
  cells)
• Completed design/fabrication of three masks for
  micro channels, inlet/outlet, and electrodes
• Completed fabrication of micro channel arrays
  (4?4 cells) on Pyrex glass (1/4 wafer)
• Completed fabrication of inlet/outlet on Pyrex.
• Performance of Single Fuel Cell
• Two different electrolyte membranes (Nafion 117
  and 202) were tested.
• A novel concept on electrocatalyst support
• Initiated a methodology to integrate
  nanoparticles into fuel cell research.
• Work Plan (10/01/07-04/30/08)
• Explore optimum conditions for fuel cell
  operation
• Prepare a complete micro fuel cell array (8?8
  cells) on Pyrex wafer (d4)
• Align and integrate in/outlets with flow channels
  and electrodes
• Explore funding opportunities for the novel
  electrocatalyst support
• Initiate I-V test for 64-cell.