Water electrolysis device for homogenization of the current density

Abstract

The invention relates to a water electrolysis device including a membrane-electrode assembly that includes a proton-exchange membrane and an anode active layer that includes an electrocatalytic material. The water electrolysis device further includes a water inlet collector and an oxygen outlet collector, a straight line connecting the water inlet collector to the oxygen outlet collector extending along a general flow direction. The water electrolysis device further includes an anode facing the anode active layer. In a section along a normal to the straight line, the anode has points that each have a combined distance with the water inlet collector and with the oxygen outlet collector, the combined distance for a first point at the periphery of the anode is at least 10% greater than the combined distance of a second point positioned on the straight line.

1 : A water electrolysis device, comprising:
 a membrane-electrode assembly, comprising a proton-exchange membrane and an anode active layer that includes an electrocatalytic material and is positioned on one face of said proton-exchange membrane;   a water inlet collector;   an oxygen outlet collector, a straight line connecting the water inlet collector to the oxygen outlet collector extending along a general flow direction;   an anode facing the anode active layer, having one end in communication with the water inlet collector and another end in communication with the oxygen outlet collector;   characterized in that:   in a section along a normal to said straight line, the anode has points that each have a combined distance with the water inlet collector and with the oxygen outlet collector, the combined distance for a first point at the periphery of the anode being at least 10% greater than the combined distance of a second point positioned on said straight line;   the surface loading of the anode active layer with electrocatalytic material at the first point being at least 10% greater than the surface loading thereof at the second point.   
     
     
         2 : The device according to  claim 1 , in which the electrocatalytic material of the anode active layer includes IrO 2  at more than 50% by weight in the solids content of this anode active layer. 
     
     
         3 : The device according to  claim 1 , in which the electrocatalytic material of the anode active layer includes IrO 2 X with X=Ru or Sn, at more than 50% by weight in the solids content of this anode active layer. 
     
     
         4 : The device according to  claim 2 , in which said anode active layer includes a mean surface loading of IrO 2  of between 1 and 3 mg/cm 2 . 
     
     
         5 : The device according to  claim 1 , in which said proton-exchange membrane has a thickness at least equal to 100 μm. 
     
     
         6 : The device according to  claim 1 , in which the combined distance for the first point (A) is at least 20% greater than the combined distance for the second point (B). 
     
     
         7 : The device according to  claim 1 , in which the anode has a circular shape. 
     
     
         8 : The device according to  claim 1 , in which said anode active layer includes a polymer matrix in which the electrocatalytic material is coated. 
     
     
         9 : The device according to  claim 1 , further comprising a permeable water diffusion element positioned between the anode active layer and the anode. 
     
     
         10 : The device according to  claim 9 , in which said permeable element comprises a stack of several screens and of a porous layer. 
     
     
         11 : The device according to  claim 1 , comprising a flow guide positioned between the anode and the anode active layer, the flow guide defining flow channels between the water inlet collector and the oxygen outlet collector. 
     
     
         12 : The device according to  claim 1 , in which said anode active layer is devoid of a carbon-based support. 
     
     
         13 : The device according to  claim 1 , further comprising:
 a cathode active layer positioned on one face of said proton-exchange membrane on the opposite side to the anode active layer;   a cathode facing the cathode active layer, the cathode and the anode being electrically conductive;   a power supply circuit configured to apply potential difference between the anode and the cathode.