Alkaline Chemistries in Microfluidic Fuel Cells
- Detailed Technology Description
- UIUC researchers have developed the ability to integrate alkaline and mixed-media electrochemistries into microfluidic fuel cells.
- Countries
- United States
- Application No.
- 7635530
- *Abstract
-
This fuel cell is an invention of miniature proportions. UIUC researchers have developed the ability to integrate alkaline and mixed-media electrochemistries into microfluidic fuel cells. This technology takes advantage of two well documented phenomena: 1. the high output of alkaline electrochemical reactions; and 2. the reliable, low-maintenance qualities of laminar flow. Microfluidic alkaline fuel cells eliminate the need for a semi-permeable membrane (PEM) and operate under the unique principles of laminar flow in which substances interact without experiencing turbulent mixing.
DESCRIPTION/DETAILS
The UIUC's development of alkaline chemistries using microfluidics advances micro-fuel cell technology closer to practical application. By designing a microfluidic fuel cell that can accept a variety of electricity-generating fuels, this development enhances the range of possibilities for the future of fuel cell technology.
Of the different types of fuel cell systems, the polymer electrolyte membrane fuel cell (PEM-FC) has been recognized as one of the most promising candidates to overcome the challenges of miniaturization. Hydrogen is one of the primary fuels used in PEM-FCs; but in order to obtain micro-PEM-FCs with practical energy densities, the lightweight, extremely flammable gas must be stored at high pressure, which requires extreme safety measures and large energy investments. Safer high energy-density fuels, such as methanol and formic acid, have been the focus of intense research as well, but they present their own unique obstacles.
Micro-scale fuel cells using a microfluidic architecture operate under a different principle than micro-scale PEM-based fuel cells. Rather than keep the reagents separated with a semi-permeable membrane, a unique Y-shaped microfabrication method allows the two chemicals to flow laminarly in parallel without experiencing turbulent mixing. This phenomenon permits a free exchange of hydroxide ions at the liquid-liquid interface without concern for the stability of a semi-permeable membrane. Alkaline reactions convert the highly energy-dense hydrocarbon methanol and oxygenated liquid into the harmless byproducts of carbon dioxide and water; microfluidic fuel cell arrays can then be arranged to handle varying wattage requirements.
APPLICATIONS
Advances in microelectronics and wireless technology have lead to a relentless demand for efficient and reliable power sources to fuel productivity. As much as half of the weight of many contemporary electronic devices can be attributed to the battery. Fuel cells have been tapped as an alternative because of their high energy density, or energy to weight ratio.
- Portable electronics: As the size of electronic equipment, such as cell phones, GPS systems and laptop computers, continues to shrink, industry demand increases for equally smaller power supplies. Customizable, high-power microfluidic fuel cells offer the potential to provide lighter, smaller solutions for such devices.
BENEFITS
Batteries common to the average household operate in alkaline chemistries because of the reaction's high electrical output and relatively low materials cost. The development of alkaline-based microfluidic fuel cells transfers that desirable combination to the cutting-edge of fuel cell technology.
- Compatible with alkaline chemistries: In addition to the acidic chemistry common to PEM-based fuel cells (PEM-FCs), this microfluidic design can be operated with a variety of electrolytes. Most notably, these microfluidic fuel cells will operate in alkaline chemistries, which are widely known to provide higher reaction kinetics, energy densities and longer life.
- Seamless chemistry alterations: In addition to the sought after alkaline chemistries, the chemical composition at the cathode and anode streams can be custom tailored to optimize electrode kinetics and overall open cell potential, without a single change to the device itself. This fuel cell can be operated in all-alkaline or mixed-media configurations. And because there is no reaction-specific catalytic membrane, the cells require no change to the physical system when accommodating different reaction media.
- Eliminates PEM-related issues: With methanol- and formic acid-based fuel cells, fuel crossover, anode dry-out, membrane clogging and cathode flooding are problems that have confronted researchers. A microfluidic device avoids these complications because there is no need to insert a membrane between the anode and cathode.
- Easily recharged: Rather than having to plug into a wall socket to rejuvenate spent batteries, fuel cells have the benefit of being instantly recharged by cartridge, much like an inkjet printer or ball-point pen. Just snap-in a new fuel source and the mechanism is ready to go.
For more information about this technology, please contact the University of Illinois at Urbana-Champaign Office of Technology Management at otm@illinois.edu.
- *IP Issue Date
- None
- *IP Type
- Utility
- Country/Region
- USA
