The present invention relates to a new strategy against the electrolyte migration through the gasket in externally manifolded MCFC stacks. This is obtained by endowing a stack of molten carbonate fuel cells (MCFCs) of an electrolyte management tool separated from the cells by an electronically conductive material which is impervious to gas, characterized by the combination of the following elements:--a positive reservoir component external to the cathode of the first cell on the positive side of the battery, wherein said reservoir consists of one ore more porous layers of electronically conductive material and comprises at least one gas distributor, and--a negative reservoir component external to the anode of the last cell on the negative side of the battery, wherein said reservoir consists of one ore more porous layers of electronically conductive material.