Patent ID: 7767360
Filing Date: 2010-08-03
Classification: H01M,Y02E

Abstract:
1. An electrochemical cell apparatus comprising: a membrane-electrode assembly (MEA) comprising a membrane having a first side and a second side opposite the first side, a first electrode in contact with the first side, and a second electrode in contact with the second side; a flow field member disposed adjacent to the first electrode opposite the membrane; and a protector member disposed between the flow field member and the first side of the membrane, the protector member having a boundary partially defined by a first surface facing toward a center of the MEA; wherein the second electrode has a boundary partially defined by a second surface facing away from the center of the MEA, the second surface disposed between the center of the MEA and the first surface; wherein a first distance from the center of the MEA to the first surface is greater than a correspondingly oriented second distance from the center of the MEA to the second surface, thereby defining a gap between the first surface and the second surface and causing a current density within the first electrode to be less than a comparable current density in the absence of the gap; wherein the first electrode has a boundary partially defined by a third surface facing away from the center of the MEA, the third surface disposed between the center of the MEA and an outer edge of the membrane, the third surface disposed at a third distance from the center of the MEA; and wherein the second distance is less than the correspondingly oriented third distance, resulting in a reduced occurrence of dendritic growths from the first electrode toward the second electrode compared with a non-reduced occurrence of dendritic growths from the first electrode toward the second electrode with the second distance equal to the correspondingly oriented third distance.