Direct methanol fuel cell
Direct methanol fuel cells or DMFCs are a subcategory of proton-exchange membrane fuel cells in which methanol is used as the fuel and a special proton-conducting polymer as the membrane (PEM). Their main advantage is in their low temperature operations and the ease of the transport of methanol, an energy-dense yet reasonably stable liquid at all environmental conditions.
Source: Wikipedia — Direct methanol fuel cell (CC BY-SA 4.0)