Electrochemical parameters of an H 2 |air fuel cell with a membrane of solid electrolyte CsHSO 4 or composites (1x ) CsHSO 4 / x SiO 2 ( x = 0.1-0.3) and different electrodes are measured at 175° C. The maximal power (3.5 mW/cm 2 at a voltage of 0.6 V) is obtained for a cell with platinum-black electrodes and an intermediate layer of a mixture of platinum black and the electrolyte material. In the absence of a platinum catalyst, CsHSO 4 and composites CsHSO 4 /SiO 2 are chemically stable in hydrogen at the operating temperature of the fuel cell.