(EP907979-A1)      In a direct methanol fuel cell (DMFC) having fuel and oxidant supply and discharge channels, a membrane-electrode unit and bipolar plates, the fuel supply channel is preceded by an evaporator so that the fuel is supplied in gaseous form for reaction at the anode. Preferably, the moisture content is greater than 70% and the methanol, water and/or inert gas concentration in the fuel can be adjusted by pumps preceding the evaporator. Also claimed is a fuel cell battery comprising a stack of the above DMFCs, the evaporator and optionally one to three pumps in the fuel feed line, as well as a CO2 separator or heat exchanger provided in the fuel exhaust line for physically or chemically separating unconsumed fuel from the CO2 reaction product. Further claimed is a method of operating a DMFC, in which the fuel is fed in gaseous form to the anode.    USE -   In a fuel cell battery useful as a mobile energy source, e.g. in automobiles, or as a large stationary energy source, e.g. in power stations or for electric current and heat supply to dwellings or office buildings.    ADVANTAGE -   The DMFC has (i) increased Faraday efficiency, even at low current density, since the cell employs load-dependent methanol supply and consumption in the anode space so that the methanol concentration is insufficient to produce a high methanol diffusion pressure towards the cathode; (ii) increased voltage since the operating temperature can be increased to minimise kinetic inhibition of the anodic reaction; and (iii) extremely low water transport through the polymeric electrolyte by addition of an inert gas (e.g. CO2 and/or N2) to reduce the water content at the anode side.    (EP907979-B1)      In a direct methanol fuel cell (DMFC) having fuel and oxidant supply and discharge channels, a membrane-electrode unit and bipolar plates, the fuel supply channel is preceded by an evaporator so that the fuel is supplied in gaseous form for reaction at the anode. Preferably, the moisture content is greater than 70% and the methanol, water and/or inert gas concentration in the fuel can be adjusted by pumps preceding the evaporator. Also claimed is a fuel cell battery comprising a stack of the above DMFCs, the evaporator and optionally one to three pumps in the fuel feed line, as well as a CO2 separator or heat exchanger provided in the fuel exhaust line for physically or chemically separating unconsumed fuel from the CO2 reaction product. Further claimed is a method of operating a DMFC, in which the fuel is fed in gaseous form to the anode.    USE -   In a fuel cell battery useful as a mobile energy source, e.g. in automobiles, or as a large stationary energy source, e.g. in power stations or for electric current and heat supply to dwellings or office buildings.    ADVANTAGE -   The DMFC has (i) increased Faraday efficiency, even at low current density, since the cell employs load-dependent methanol supply and consumption in the anode space so that the methanol concentration is insufficient to produce a high methanol diffusion pressure towards the cathode; (ii) increased voltage since the operating temperature can be increased to minimise kinetic inhibition of the anodic reaction; and (iii) extremely low water transport through the polymeric electrolyte by addition of an inert gas (e.g. CO2 and/or N2) to reduce the water content at the anode side.    (JP2000512797-W)      In a direct methanol fuel cell (DMFC) having fuel and oxidant supply and discharge channels, a membrane-electrode unit and bipolar plates, the fuel supply channel is preceded by an evaporator so that the fuel is supplied in gaseous form for reaction at the anode. Preferably, the moisture content is greater than 70% and the methanol, water and/or inert gas concentration in the fuel can be adjusted by pumps preceding the evaporator. Also claimed is a fuel cell battery comprising a stack of the above DMFCs, the evaporator and optionally one to three pumps in the fuel feed line, as well as a CO2 separator or heat exchanger provided in the fuel exhaust line for physically or chemically separating unconsumed fuel from the CO2 reaction product. Further claimed is a method of operating a DMFC, in which the fuel is fed in gaseous form to the anode.    USE -   In a fuel cell battery useful as a mobile energy source, e.g. in automobiles, or as a large stationary energy source, e.g. in power stations or for electric current and heat supply to dwellings or office buildings.    ADVANTAGE -   The DMFC has (i) increased Faraday efficiency, even at low current density, since the cell employs load-dependent methanol supply and consumption in the anode space so that the methanol concentration is insufficient to produce a high methanol diffusion pressure towards the cathode; (ii) increased voltage since the operating temperature can be increased to minimise kinetic inhibition of the anodic reaction; and (iii) extremely low water transport through the polymeric electrolyte by addition of an inert gas (e.g. CO2 and/or N2) to reduce the water content at the anode side.