The present invention concerns a device for producing electrical energy comprising two cells intended to contain two solutions of different concentrations of at least one solute and separated by at least one separation membrane in which channels are arranged, each of the cells being provided with an electrode intended to be in contact with the solution that said cell will contain, characterized in that the walls of the channels consist of a material chosen from boron nitride, carbon doped with boron, boron nitride doped with carbon, or any other mixture of the elements boron, carbon and nitrogen, and a method for producing electrical energy that implements such a device.