Electrode unit, electrolytic cell comprising electrode unit and electrolytic device

Abstract

According to one embodiment, an electrode unit of an electrolytic device includes a first electrode including a first surface, a second surface located on an opposite side to the first surface, a plurality of first pores opened in the first surface, a plurality of second pores opened in the second surface and having an opening area greater than that of the first pores, and a plurality of the first pores communicating with a respective one of the second pores, a second electrode opposing the first surface of the first electrode, and a continuous porous membrane arranged between the first electrode and the second electrode, so as to cover the first surface of the first electrode.

1 : An electrode unit comprising:
 a first electrode including: a first surface, a second surface located on an opposite side to the first surface, a plurality of first pores opened in the first surface, a plurality of second pores opened in the second surface and having an opening area greater than that of the first pores, a plurality of the first pores communicating with a respective one of the second pores;   a second electrode opposing the first surface of the first electrode; and   a continuous porous membrane arranged between the first electrode and the second electrode, so as to cover the first surface of the first electrode.   
     
     
         2 : The electrode unit of  claim 1 , wherein an opening area of the first pores opened in the first surface is 0.01 to 4 mm 2 . 
     
     
         3 : The electrode unit of  claim 1 , wherein an opening area of the second pores opened in the second surface is 1 to 1600 mm 2 . 
     
     
         4 : The electrode unit of  claim 1 , wherein a number density of the first pores per unit area is higher than that of the second pores per unit area. 
     
     
         5 : The electrode unit of  claim 1 , wherein a catalytic layer is formed on the first surface and the second surface of the electrode, and an amount of the catalytic layer per unit area differs from the first surface to the second surface. 
     
     
         6 : The electrode unit of  claim 1 , wherein the first pores are formed to have a tapered surface or a curved surface which widens towards the first surface. 
     
     
         7 : The electrode unit of  claim 1 , wherein the first electrode includes recess portions formed in the first surface, and the first surface is formed flat except for the first pores and the recess portions. 
     
     
         8 : The electrode unit of  claim 7 , wherein an average surface roughness of a flat portion of the first electrode is 10% or less of an average thickness of the porous membrane. 
     
     
         9 : The electrode unit of  claim 1 , wherein an opening ratio of first pores located in a central portion of the first electrode is less than an opening ratio of first pores located in a peripheral portion of the first electrode. 
     
     
         10 : The electrode unit of  claim 1 , further comprising: an electrically insulating film which inhibits liquid from passing therethrough and is provided on at least a portion of the first surface of the first electrode. 
     
     
         11 : The electrode unit of  claim 1 , wherein the second electrode has a porous structure including a plurality of through-holes. 
     
     
         12 : The electrode unit of  claim 1 , wherein the porous membrane is a polymer membrane containing a fluorine atom or a chlorine atom in a main chain thereof. 
     
     
         13 : The electrode unit of  claim 1 , wherein the porous membrane is a glass cloth. 
     
     
         14 : The electrode unit of  claim 1 , wherein the porous membrane is a membrane including in-planerly or three-dimensionally irregular pores and containing inorganic oxide. 
     
     
         15 : The electrode unit of  claim 1 , wherein the porous membrane is a multi-layer film in which a plurality of porous films having different pore diameters are stacked one on another. 
     
     
         16 : The electrode unit of  claim 1 , further comprising: a diaphragm provided between the first surface of the first electrode and the second electrode, which allows at least one of ion and liquid to pass therethrough, and
 wherein the porous membrane is interposed between the first surface of the first electrode and the diaphragm.   
     
     
         17 : The electrode unit of  claim 1 , further comprising:
 two diaphragms provided between the first electrode and the second electrode so as to oppose each other; and   an electrolyte holding structure located between the two diaphragms to hold electrolyte.   
     
     
         18 : An electrolytic cell comprising: an electrolytic chamber and an electrode unit of  claim 1 , provided in the electrolytic chamber. 
     
     
         19 : An electrolytic device comprising:
 an electrolytic cell including an electrolytic chamber;   an electrode unit of  claim 1 , provided in the electrolytic chamber; and   a power supply which applies a voltage to the first electrode and the second electrode of the electrode unit.   
     
     
         20 : The electrolytic device of  claim 19 , wherein an electrolyte containing chloride ions is electrolyzed by the electrode unit.