Patent ID: 8043754

Claim:
A polymer electrolyte fuel cell comprising: an anode reactant supply plate; an anode current collector; an anode gas diffusion layer; a cathode reactant supply plate; a cathode current collector; a cathode gas diffusion layer; a polymer membrane electrode assembly (MEA) sandwiched between the anode gas diffusion layer and the cathode gas diffusion layer; at least one of the anode current collector and the cathode current collector being electrically separated into a number of segments, each of the at least one segmented current collectors including a gold plated copper plate, each segment of at least a subgroup of segments being separately connected to an electronic drive and analysis circuitry which performs in parallel impedance measurements in a frequency range of 0.1 mHz to 50 kHz of the respective segments; the electronic drive and analysis circuitry including for each segment of the at least one segmented current collector a closed-loop Hall effect current sensor circuit mounted on a printed circuit board directly connected to a current drain of the at least one segmented current collector in order to produce a segment specific ac voltage output proportional to the ac current in the respective segment; said electronic drive and analysis circuitry further including an electronic load common to all segments, to control the overall cell current; and said electronic load being adjustable in the range up to 1000 A.