NOVELTY - An electrolyte is dispersed in the pores of a porous, fibrous membrane separator. Electroconductive fibres are contacted or covered with an electrocatalyst to form electrodes. At least one feed inlet and outlet is provided to and from the electrodes.    USE - As a fuel cell or chloroalkali cell (claimed) and batteries (primary and secondary).    ADVANTAGE - A small amount of the electrocatalyst can be impregnated, coated or extruded on a fibrous substance to form an electrode.    DETAILED DESCRIPTION - The electrodes comprise (I) an inner electrode (a) formed from electroconductive fibres contacted or covered with an electrocatalyst and housed in the bore of the membrane separator in which the housing has a lumen allowing free passage of liquid or gaseous feed components, or (b) formed by coating or impregnating an electrocatalyst on the shell side of a second inner hollow porous separator and housed in the bore of the first separator in which the lumen of the inner separator allows free passage of liquid or gaseous feed components, or (c) formed from an inner hollow porous separator with distinct fibrous electrodes contacting the shell side of the inner hollow porous separator, the electrodes formed from electroconductive fibres contacted or covered with an electrocatalyst, and housed in the bore of the first separator, and (II) an outer electrode consisting of either an electrocatalyst and an electroconductive material surrounding or impregnating the shell side o f the separator, or electroconductive fibres contacted or covered with an electrocatalyst surrounding the separator. An INDEPENDENT CLAIM is also included for an electrochemical module comprising multiple cells as described above, in a casing with access ports for liquid and gaseous components. The cells are bundled or wound around a mandrel. The electrodes extend outside the lumen and through a tube sheet and are connected to positive and negative terminals.    DESCRIPTION OF DRAWING(S) - The drawing shows the electrochemical cell.