INTEGRATED MICRO PEM FUEL CELL WITH SELF-REGULATED HYDROGEN GENERATION FROM AMMONIA BORANE

摘要

The demand for power sources with superior performance has increased as a result of the rapid growth of the portable electronics market, such as cell phones, global positioning systems (GPS), personal digital assistants (PDA), digital cameras, and laptop computers. This growth has compelled the scientific community to investigate possible power sources with high power and energy densities to deliver high performance and support a long operation time. Compared to rechargeable batteries, hydrogen proton exchange membrane (PEM) fuel cells have shown the potential to offer high energy densities if high energy density fuels can be used. However, having a reliable and efficient on-board hydrogen generator is still one of the main challenges for micro hydrogen PEM fuel cells. In order to solve this problem, we have previously demonstrated a self-circulated and self-regulated microfluidic hydrogen generator for micro fuel cell applications without parasitic power consumption. The microfluidic hydrogen generator was based on the catalytic hydrolysis reaction of ammonia borane (NH3BH3) due to its large theoretical hydrogen content, controllable chemical reaction using aqueous based solutions, stable aqueous solution without alkaline stabilizer, and better catalyst durability. However, the previous device was fabricated on silicon substrates using MEMS fabrication processes that are not cost-effective for mass production. In addition, the microfluidic hydrogen generator and PEM fuel cell were connected by tubing. The large dead volume associated with tubing increased the response time of self-regulation.