Electrochemical cell with a porous support plate

Abstract

An improved electrochemical cell such as a fuel cell is disclosed including a porous support plate for enhancing transport of fluids throughout the cell and for enhancing capacitance and transient response capability of the cell. The electrochemical cell includes an electrolyte having opposed major surfaces with an anode and a cathode electrode supported in intimate contact with the opposed major surfaces. A porous support plate is secured adjacent each electrode, and each porous support plate includes a contact bi-layer in intimate contact with the electrode. Each contact bi-layer is comprised of a hydrophobic phase including a mixture of carbon black and a hydrophobic polymer defining a network of hydrophobic gas passages and each contact bi-layer also includes a hydrophilic phase including a mixture of carbon black and a proton exchange resin defining a network of hydrophilic liquid passages integrated throughout the contact bi-layer. Each porous support plate also includes a porous substrate layer adjacent and supporting the contact bi-layer. A method of manufacture of the porous support plate includes the steps of preparing a hydrophobic phase compound, preparing a hydrophilic phase compound, mixing and filtering the two compounds to form a contact bi-layer, transferring the contact bi-layer onto a porous substrate layer to form a porous support plate. An alternative method includes an additional step of activating the contact bi-layer in an acid bath at controlled electrical potentials to enhance capacitance of the cell.