FUEL CELL COMPRISING AN AMMONIUM POLYPHOSPHATE COMPOSITE AS A PROTON-CONDUCTING SOLID ELECTROLYTE, FOR OPERATING AT TEMPERATURES BETWEEN 200 AND 600 °C

摘要

The invention relates to a fuel cell comprising a proton-conducting solid electrolyte, for operating in an average temperature range (200-600 °C). According to the invention, composites containing ammonium polyphosphate (APP-K) are used as the electrolyte in the fuel cell. The ammonium polyphosphate which forms the composites is a proton-conducting material which is embedded in the pores of a porous matrix, and said matrix can consist of proton-conducting material itself. Said ammonium polyphosphate (APP) consists of NH4PO3-HPO3, or [NH4PO3]x [SiO2]y, or [NH4PO3]x [GeO2]y, or [NH4PO3]x [Al(PO3)3]y. The porous matrix, in which the APP is embedded, consists either of thermostable non-woven polymers, glass fibres, or porous, inorganic materials. The operation of fuel cells in said temperature range offers the advantage that the anode catalyst is considerably more tolerant towards carbon monoxide or is even insensitive from ca. 300 °C towards the same, and material problems which occur in high temperature ranges are insignificant. Furthermore, the electrode kinetics are significantly increased in comparison with low temperature ranges. Using a suitable catalyst, reformed hydrogen, methanol and superior alcohols can thus be directly reacted in said fuel cell without any loss of power. Not only can costs be reduced, but also especially the power curve of the fuel cell can be improved, and the system can be significantly simplified.