Abstract: A fuel cell stack includes at least two stacked fuel cell units which are held together by a material which has sealing and fixing properties. A method for assembling a fuel cell stack is also provided.

Abstract: A fuel cell installation and a method for operating a fuel cell installation with a dynamic power control are provided. The dynamic power control is achieved by additionally connecting at least one subsystem which is kept ready for operation, a starter system and/or a low-voltage unit for nighttime operation and/or an on-board power supply.

Abstract: The method determines the fuel concentration in fluidic fuels for fuel cells, and in particular the alcohol concentration in an alcohol/water mixture for fuel cells operated with the mixture, such as direct methanol fuel cells. The alcohol/water mixture is passed through a heating section at a constant flow rate, a known quantity of heat is supplied to the mixture, the temperature difference between the entry and exit of the heating section is measured and the alcohol concentration is determined therefrom.

Abstract: In a method for determining the alcohol concentration in the alcohol/water mixture of fuel cells that are operated with this mixture, in particular for direct methanol fuel cells, the alcohol/water mixture is pumped through a constriction. The differential pressure between the entry to and exit from the constriction and, if appropriate, the flow velocity of the mixture through the constriction are measured, and the alcohol concentration is determined therefrom.

Abstract: The fuel cell installation is operated at temperatures between 80° C. and 300° C. and ensures that the efficiency is optimized, since the waste heat from the fuel cell stack is utilized at least in some other way. For the purpose, there is provided an evaporator upstream of the fuel cell stack. At least one line is connected to the fuel cell stack for rendering available a heat content from at least a part of the fuel cell stack to be utilized in one or more further units of the installation.

Abstract: High-temperature polymer electrolyte membrane (HTM) fuel cells, installations including HTM fuel cells, methods for operating an HTM fuel cell, and an HTM fuel cell installation apply the principle of the known PEM fuel cell and overcomes the major drawback of this fuel cell. By selecting a new electrolyte and changing the operating conditions, in particular the temperature and the pressure, the fuel cells do not depend on water content.

Abstract: A high-temperature membrane (HTM) fuel cell, a method for operating an HTM fuel cell, and an HTM fuel cell battery prevent the electrolyte from being washed out while the battery is starting by having the product water not condensing within the fuel cell unit and by heating the fuel cell unit, in a locally limited manner, to evaporate the product water.