Direct methanol fuel cells : progress, problems and prospects

In spite of the substantial technological advances made in the area of rechargeable lithium-ion batteries, the need for high energy density portable power sources continues to grow in the civilian and military sector. This need for high energy density power sources is driven by the increased energy usage by multifunctional electronic equipment, the decreasing size of portable electronic equipment, and the need for operating continuously without interruptions for re-charging. Thus, portable fuel cell technologies based on high energy fuels such as methanol continue to be extremely attractive. The inherent high energy density of methanol as a fuel presents the potential of a ten-fold increase in specific energy over the state-of-art lithium ion batteries. In addition, the possibility of instant re-fueling with a fresh fuel cartridge mitigates the inconvenience of battery re-charging arising from downtime, the need to be close to source of primary power, and the mass and volume penalty associated with additional batteries and recharging equipment. As a result, there has been considerable effort in the last 15 years to advance the technology of methanol-based portable fuel cells. This paper attempts to survey the progress, problems and prospects of realizing the advantages of portable power sources based on the direct methanol fuel cell (DMFC) technology.