Abstract: Some embodiments of the present invention provide systems and methods for more accurately determining the cause of a particular fault in an electrochemical cell based on an impedance measurement characterizing the electrochemical cell. In some very specific embodiments the impedance of an electrochemical cell or stack is measured across a range of frequencies to determine a corresponding impedance signature characterizing the present state of the electrochemical cell or stack. By evaluating the impedance signature in comparison to reference information, a number of faults may be detected. In some more specific embodiments once a corresponding specific fault is determined and an indication is provided to a user and/or a balance-of-plant monitoring system, which may be used to adjust the operating parameters of an electrochemical cell module to compensate for and/or reverse the detrimental effects caused by a particular fault.

Abstract: Embodiments of the pertinent invention relates to apparatus, systems and methods for diagnostic testing of an electrochemical cell stack, such as a fuel cell stack or an electrolyzer cell stack. According to one embodiment, the apparatus comprises a multiplexer for switching current to one or more cells in the electrochemical cell stack, a voltage monitor for monitoring the voltage between the anode plate and the cathode plate of one or more cells, a power supply module for supplying power to the multiplexer and a gas supply module for supplying fuel gas and non-fuel gas to the electrochemical cell stack. The apparatus further comprises a control module electrically connected to and configured to control the multiplexer, the voltage monitor, the power supply module and the gas supply module to conduct automatic diagnostic testing of the electrochemical cell stack.

Abstract: Embodiments of the present invention relate to multiplexing apparatus, systems and methods for use in diagnostic testing of an electrochemical cell stack, such as a fuel cell stack or an electrolyzer cell stack. According to one embodiment, the apparatus comprises a multiplexer for switching current to one or more cells in the electrochemical cell stack and a power supply module for supplying power to the multiplexer. The apparatus further comprises a control module electrically connected to and configured to control the multiplexer and the power supply module to supply current to individual cells or groups of cells during automatic diagnostic testing of the electrochemical cell stack. The multiplexer comprises a microprocessor and a plurality of switching circuits adapted to supply current or voltage from the power supply module to the cells.

Abstract: A membrane electrode assembly for an electrochemical cell assembly is provided with a modified catalyst layout. The modified catalyst layout improves reactant fluid flow along the membrane electrode assembly, reduces wear on the membrane electrode assembly and improves electrochemical cell efficiency during operation.