NOVELTY - The fuel cell e.g. direct methanol fuel cell useful in laptop computers, telephones and portable tools, comprises a leak-tight container having an anode (1) and a cathode (2) separated by an electrolytic membrane (3) and in contact with an electrolysable liquid medium introduced by line, current collectors connected on one hand to the anode and cathode and on the other hand to an electrical circuit (4) using an aqueous medium having a fuel that is soluble in the aqueous medium at a temperature of use of the cell, and a hydrolyser (10).    USE - The fuel cell such as direct methanol fuel cell, proton exchange membrane fuel cell, molten carbonate fuel cell or phosphoric acid fuel cell is useful in laptop computers, telephone and portable tools for converting the energy of a chemical reaction into electricity.    ADVANTAGE - The fuel cell has improved physiochemical properties such as good solubility and high energy densities.    DETAILED DESCRIPTION - The fuel cell e.g. direct methanol fuel cell useful in laptop computers, telephones and portable tools, comprises a leak-tight container having an anode (1) and a cathode (2) separated by an electrolytic membrane (3) and in contact with an electrolysable liquid medium introduced by line, current collectors connected on one hand to the anode and cathode and on the other hand to an electrical circuit (4) using an aqueous medium having a fuel that is soluble in the aqueous medium at a temperature of use of the cell, and a hydrolyser (10) containing a solid acidic catalyst to hydrolyze the aqueous medium that is implemented between a fuel cartridge and the anode. Carbon dioxide is extracted by line. The oxygen is introduced in cell by other line, and water produced is extracted by line. The solid acidic catalyst is stacked in the hydrolyser to obtain a compact porous and high surface area structure, which enables the fuel circulation and fast hydrolysis. The hydrolyser is located between the fuel cartridge and a fuel inlet of the fuel cell as a film layer on top of the anode, and equipped with heating device. A valve is implemented between the fuel cartridge and the hydrolyser. The fuel of the liquid medium is an oxycarbon fuel and a fuel containing compounds of the polyoxymethylene dimethyl ether. The solid acidic catalyst is acidic resin, acid polymers deposited on carbon powder, paper or fibers, and surface modified carbon powder with acidic groups or acidic oxides.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a fuel cell.    Anode (1)    Cathode (2)    Electrolytic membrane (3)    Electrical circuit (4)    Hydrolyser. (10)