Gas percolation barrier for gas fed electrode

摘要

A porous gas fed electrode adapted to operate in a large capacity cell with a stable three phase interface in the electrode thereby avoiding the problems of gas percolation can be readily achieved in a simple and inexpensive manner by applying a porous hydrophilic layer on the surface of the electrode which is in contact with the aqueous electrolyte. Due to the high capillary pressure exhibited by liquids in hydrophilic pores, very high gas pressures are required to force the gas through the structure and the loss of gas into the electrolyte is thereby eliminated. In addition, a gas pressure in the gas compartment of the electrochemical cell employing such an electrode can be raised to balance the electrolyte pressure at the bottom of the electrode thereby effectively preventing electrolyte seepage into the gas compartment. Thus, in its simplest sense, the present invention comprises a porous gas fed electrode structure having a hydrophilic layer on the surface of the electrode which contacts liquid electrolyte.