Доступ предоставлен для: Guest
Thermal Sciences 2004. Proceedings of the ASME - ZSIS International Thermal Science Seminar II
June, 13-16, 2004, Bled, Slovenia

DOI: 10.1615/ICHMT.2004.IntThermSciSemin


ISBN Print: 978-9-61913-930-1

Thermo-Fluids Considerations in the Development of a Silicon-based Micro-scale Direct Methanol Fuel Cell

pages 171-180
DOI: 10.1615/ICHMT.2004.IntThermSciSemin.150
Get accessGet access

Краткое описание

A silicon-based micro-scale Direct Methanol Fuel Cell (DMFC) system is under development at Carnegie Mellon University, as a substitute for lithium-ion batteries to power hand-held electronic devices. The DMFC is simple in design, operational in any orientation and environmentally benign. The air flow and the methanol circulation are both at a natural convection draft, while a passive gas bubble separator removes CO2 from the methanol chamber. The design and operation of the passive gas separator system, which has been successfully fabricated and tested, is described.
Micro-scale Direct Methanol Fuel Cells have great potential for early applications in portable electronics due to their higher tolerance of power cost. However, challenges in system integration have to be overcome. A major issue is the development of micro-fluidics, which includes the micro pump for anode liquid re-circulation and for recycling the excess water from the cathode back to the anode, as well as the passive CO2 gas bubble separation from the anode side liquids. In addition, the seamless integration of various micro-fluidic components and the electronic control system has been an essential concern for system reliability and cost reduction.
The DMFC is designed using MEMS technology. To achieve high energy density, the excess water at the cathode is collected and pumped back to the anode. This micro fuel cell contains several unique features. A silicon wafer with an array of etched holes selectively coated with a non-wetting agent is used at the cathode to collect the water effectively. A silicon membrane micro pump is developed for pumping the collected water back to the anode. Finally, a passive micro-scale CO2 bubble separator is developed to remove the gas bubbles from the anode stream. All of these silicon-based components are fabricated with a set of common processes on the same silicon wafer, such that interconnections are eliminated and fabrication cost is minimized. The resulting micro-scale fuel cell has an energy density four times larger than that of current lithium-ion batteries.

Портал Begell Электронная Бибилиотека e-Книги Журналы Справочники и Сборники статей Коллекции Цены и условия подписки Begell House Контакты Language English 中文 Русский Português German French Spain