Water electrolysis module having improved stacking stability

Abstract

There is disclosed a water electrolysis stack in which a current collector, a cathode cell frame, a membrane electrode assembly, and an anode cell frame are sequentially stacked and fastened by a fastening member, wherein the water electrolysis stack has one or more through holes through which the current collector, the cathode cell frame, and the anode cell frame pass, the anode cell frame has a counter bore continued from the through hole and has a greater size than the through hole, and the fastening member includes a head seated on the counter bore, a shaft extending from the head and passing through the through hole, and a hook provided along an outer circumferential surface of one end portion of the shaft and protruding outward from the through hole to provide a compression force in a stacking direction.

What is claimed is: 
     
         1 . A water electrolysis stack in which a current collector, a cathode cell frame, a membrane electrode assembly, and an anode cell frame are sequentially stacked and fastened by a fastening member, wherein the water electrolysis stack has one or more through holes through which the current collector, the cathode cell frame, and the anode cell frame pass,
 the anode cell frame has a counter bore continued from the through hole and has a greater size than the through hole, and   the fastening member includes a head seated on the counter bore, a shaft extending from the head and passing through the through hole, and a hook provided along an outer circumferential surface of one end portion of the shaft and protruding outward from the through hole to provide a compression force in a stacking direction.   
     
     
         2 . The water electrolysis stack of  claim 1 , wherein the one end portion of the shaft is branched into a plurality of portions and has radial elasticity. 
     
     
         3 . The water electrolysis stack of  claim 1 , wherein a groove is provided in an upper surface of the head,
 a depth of the groove is greater than or equal to a thickness of the hook, and   an area of the groove is greater than or equal to an area of the hook.   
     
     
         4 . The water electrolysis stack of  claim 1 , wherein a central portion of the cathode cell frame is provided with a cathode fluid diffusion layer, and a central portion of the anode cell frame is provided with an anode fluid diffusion layer, and
 a central portion of the membrane electrode assembly is held by the cathode fluid diffusion layer and the anode fluid diffusion layer, and an edge portion of the membrane electrode assembly is held by the cathode cell frame and the anode cell frame.   
     
     
         5 . The water electrolysis stack of  claim 4 , wherein the cathode cell frame has a cathode cell frame concave portion which accommodates a cathode cell frame gasket for preventing cross leakage between a cathode electrode and an anode electrode of the membrane electrode assembly,
 the anode cell frame has an anode cell frame concave portion which accommodates an anode cell frame gasket for preventing cross leakage between the cathode electrode and the anode electrode of the membrane electrode assembly, and   the cathode cell frame gasket has a protrusion formed to protrude toward the anode cell frame concave portion to surround a side surface of the membrane electrode assembly.   
     
     
         6 . The water electrolysis stack of  claim 5 , wherein an area of the anode fluid diffusion layer is greater than an area of the cathode fluid diffusion layer, and
 a contact area of the anode cell frame and the membrane electrode assembly is greater than a contact area of the cathode cell frame and the membrane electrode assembly.