| PROPOSAL NUMBER: | 14.01-9798 (For NASA Use Only - Chron: 000203 ) |
| PROPOSAL TITLE: | Hydrogen-Air Fuel Cell for High Altitude Aircraft Use |
TECHNICAL ABSTRACT (LIMIT 200 WORDS)
UAVs are receiving increasing attention for a variety of missions. Fuel cells offer an efficient means to convert the chemical energy in hydrogen to electricity. Current developments in solar-electric aircraft indicate that operating at 60,000 feet requires 1,512 kWh/week from 66 - 84 kg of hydrogen.
Utilizing oxygen from the atmosphere requires a special low-pressure fuel cell. In Phase I we demonstrated power densities of 105 mW/cm_ at 2 psia. Producing sufficient power from a stack of reasonable weight requires novel bipolar plate structures and gas diffusion structures with conductive cores. This produces flow fields with large open fractions, promoting gas flow at low back pressures and reducing mass. The most effective flow field-electrode combination consisted of polymer cell frames with titanium gas barriers and thin carbon rods passing through the barriers. The rods are in direct contact with metal conductive elements within each electrode. This single conductor connecting a pair of electrodes minimizes resistance. Phase II will lead to further improvements in low-pressure air cathodes and the fabrication, demonstration under simulated high altitude conditions, and delivery of a kilowatt-sized stack. This stack is projected to have a repeating unit power density of 240 W/kg when operating at 50,000 feet.
POTENTIAL COMMERCIAL APPLICATIONS
UAVs for use as telecommunication relay systems are potentially a multibillion dollar market within ten years. The work proposed here develops an enabling technology for deploying these aircraft at lower cost. The same technology can also be applied to reduce the weight of fuel cell stacks intended for terestrial applications as well, and this is a potentially larger market.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR
(Name, Organization Name, Mail Address, City/State/Zip)
Alan Cisar
Lynntech, Inc.
7610 Eastmark Drive
College Station , TX 77840 - 4024
NAME AND ADDRESS OF OFFEROR
(Firm Name, Mail Address, City/State/Zip)
Lynntech, Inc.
7610 Eastmark Drive
College Station , TX 77840 - 4024