Electrochemical cells generally include an anode and a cathode separated by an electrolyte. A well-known use of electrochemical cells is in a fuel cell (a cell that converts fuel and oxidants to electrical energy) that uses a proton exchange membrane (hereafter “PEM”) as the electrolyte, for example direct methanol fuel cells. In such a cell, a reactant or reducing fluid such as methanol is supplied to the anode, and an oxidant such as oxygen is supplied to the cathode. The methanol electrochemically reacts at a surface of the anode to produce hydrogen ions and electrons. The electrons are conducted to an external load circuit and then returned to the cathode, while hydrogen ions transfer through the electrolyte to the cathode, where they react with the oxidant and electrons to produce water and release thermal energy.
Generally, within the fuel cell, the structure consisting of the PEM typically having its surfaces coated with a catalyst/carbon/binder layer and sandwiched between two microporous conductive layers (which function as the gas diffusion layers and current collectors) is known as the membrane electrode assembly (MEA).
Generally within the art, the process of making an MEA is well established, such that individual MEA's are produced manually or by automated processes. In the manual processes, each gas diffusion electrode and/or gas diffusion layer is individually applied for each element of the array. The disadvantage of such processes include, inter alia, a great degree of difficulty in aligning the elements by hand, which makes the process very time consuming and very expensive to implement. Furthermore, technologies developed to make conventional non-array MEA's cannot be readily extended to produce arrays due to the small dimensions, accurate alignment requirements and the electrical isolation between the array elements.
USPTO Backgrounds
USPTO Backgrounds