Solid fuel type hydrogen fuel cells deliver high efficiency with increased safety

September 20, 2012 // By Paul Buckley
ROHM has collaborated with Kyoto-based Aquafairy Corp., and Kyoto University to develop compact, lightweight, high-power hydrogen fuel cells designed to power smartphones and other portable devices.

The fuel cells claim to overcome the drawbacks of dry cells, lithium-ion cells, and direct methanol fuel cells, by reducing weight and increasing output power while providing a higher level of safety, making it possible to provide power in places where AC power is not available or cannot be used.

Fuel cells can be made smaller, lighter, and more efficient than conventional storage and rechargeable cells, to drive expansion into new markets and applications. Methanol fuel cells have several disadvantages that prevent widespread acceptance. Unlike hydrogen fuel cells, it is difficult to increase power output with methanl fuel cells. Hydrogen fuel cells require the use of cylinders, making them harder to handle and hinder efforts towards greater miniaturization.

ROHM, together with Aquafairy, has succeeded in solidifying calcium hydride in a sheet configuration using proprietary technologies, generating approximately 4.5 liters of hydrogen from a sheet less than 3 cc in volume (measuring 38 x 38 x 2 mm), providing a power output of 5 Whr. The hydrogen fuel cells are compact and can operate at ambient temperatures, making them suitable for use in smartphone chargers, tablet PCs, as power sources outdoors and in remote areas, and in emergency backup power supplies. In addition, they emit no carbon dioxide or hazardous gases and can be disposed of as general waste.

Professor Kazuyuki Hirao in Kyoto University’s Graduate School of Engineering commentd: "We have already discovered a new, high-efficiency, low-priced calcium compound that can be incorporated in fuel cell systems and easily broken down into raw materials and recycled using a special laser. This next-generation regenerative recycling hydrogen-generating agent is currently being developed at the Kyodai Katsura Venture Plaza adjacent to Kyoto University’s Katsura Campus".

ROHM, Aquafairy, and Kyoto University will continue to work on assessing reliability and making further improvements, with production targeted for April 2013. The fuel cells will be displayed at CEATEC (held in October 2012 in Tokyo) and Electronica