The cation exchange membrane used in {HEAD ~ the cell} of {TAIL ~ this invention} may contain any of sulfonic, carboxylic and phosphoric acid groups as an ion exchange group 
The cation exchange membrane used in { HEAD ~ the cell } of { TAIL ~ this invention } may contain any of sulfonic , carboxylic and phosphoric acid groups as an ion exchange group
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH