Differential pressure electrolysis cell and differential pressure electrolysis stack

Abstract

A differential pressure electrolysis cell includes a membrane electrode assembly, a first separator, a second separator, a first current collector, a second current collector, and a pressing member. The pressing member includes a sheet portion that is formed of a polymer material having an electrical insulating property so as to be elastically deformable, and is disposed between the second current collector and the second separator in a state of being compressed and deformed in a stacking direction of the membrane electrode assembly.

1 . A differential pressure electrolysis cell comprising:
 a membrane electrode assembly including an electrolyte membrane, a first electrode catalyst layer stacked on one surface of the electrolyte membrane, and a second electrode catalyst layer stacked on another surface of the electrolyte membrane;   a first separator located across the electrolyte membrane from the second electrode catalyst layer;   a second separator located across the electrolyte membrane from the first electrode catalyst layer;   a first current collector disposed between the first separator and the first electrode catalyst layer;   a second current collector disposed between the second separator and the second electrode catalyst layer; and   a pressing member sandwiched and held between the second current collector and the second separator and configured to press the second current collector toward the second electrode catalyst layer;   wherein the differential pressure electrolysis cell applies a voltage between the first current collector and the second current collector to electrolyze a fluid supplied to the membrane electrode assembly and thereby generate a gas in the second electrode catalyst layer, and is configured to cause the gas to have a higher pressure than a pressure of the fluid, and   the pressing member includes a sheet portion that is formed of a polymer material having an electrical insulating property so as to be elastically deformable, and is disposed between the second current collector and the second separator in a state of being compressed and deformed in a stacking direction of the membrane electrode assembly.   
     
     
         2 . The differential pressure electrolysis cell according to  claim 1 , wherein the pressing member includes a metal plate provided inside the sheet portion. 
     
     
         3 . The differential pressure electrolysis cell according to  claim 1 , wherein the pressing member includes a metal plate extending in a planar direction of the membrane electrode assembly, and
 the sheet portion covers the metal plate from both sides in the stacking direction.   
     
     
         4 . The differential pressure electrolysis cell according to  claim 1 , further comprising a sealing portion having an annular shape and being formed of a polymer material having an electrical insulating property so as to be elastically deformable and being configured to seal a gap between the second separator and an outer peripheral portion of the membrane electrode assembly protruding outward in a planar direction from the second current collector,
 wherein the sealing portion is formed integrally with the sheet portion.   
     
     
         5 . The differential pressure electrolysis cell according to  claim 4 , wherein a reinforcing portion made of metal is provided inside the sealing portion. 
     
     
         6 . The differential pressure electrolysis cell according to  claim 5 , wherein the reinforcing portion extends annularly along the sealing portion. 
     
     
         7 . The differential pressure electrolysis cell according to  claim 5 , wherein the pressing member includes a metal plate provided inside the sealing portion, and
 the reinforcing portion is connected to the metal plate.   
     
     
         8 . The differential pressure electrolysis cell according to  claim 4 , further comprising a pressure resistant member having an annular shape and covering the sealing portion from outside in the planar direction,
 wherein the pressure resistant member is in contact with the sealing portion.   
     
     
         9 . The differential pressure electrolysis cell according to  claim 4 , wherein the sealing portion is in contact with or close to the second current collector. 
     
     
         10 . A differential pressure electrolysis stack comprising a stack of a plurality of differential pressure electrolysis cells,
 wherein each of the plurality of differential pressure electrolysis cells is the differential pressure electrolysis cell according to  claim 1 .