摘要:
Components that include catalyst layers used in membrane electrode assemblies (MEAs), and methods of making such components are described. The catalyst layers yield more uniform current distributions across the active area of the MEA during operation. The catalyst layers may have a uniform catalyst activity profile of a less active catalyst to achieve more uniform current density over the MEA active area. The catalyst layers may have a variable activity profile, such as an activity profile with a varying slope, to compensate for the inherent nonlinearities of catalyst utilization during operation of an electrochemical fuel cell. Desired variable catalyst activity profiles may be achieved, for example, by varying the catalyst loading across the MEA from inlet to outlet ports or by varying the surface area of the catalyst loading or by varying the surface area of the catalyst support elements.
摘要:
A fuel cell stack is provided comprising fuel cell modules least compression plates; and at least one plurality of mechanical linkages connecting a pair of compression plates located on either side of at least one fuel cell module, which may be engaged to maintain a predetermined gap distance between the pair of compression plates. The present invention additionally provides a fuel cell stack comprising: fuel cell modules stacked alternately with compression plates; mechanical linkages connecting a first pair of compression plates directly adjacent to a first fuel cell module; mechanical linkages connecting a second pair of compression plates directly adjacent to a second fuel cell module; where a) the first and second fuel cell modules may be maintained under compression, and b) the compression on each fuel cell module may be adjusted essentially independently of the compression on the other.
摘要:
Components that include catalyst layers used in membrane electrode assemblies (MEAs), and methods of making such components are described. The catalyst layers yield more uniform current distributions across the active area of the MEA during operation. The catalyst layers may have a uniform catalyst activity profile of a less active catalyst to achieve more uniform current density over the MEA active area. The catalyst layers may have a variable activity profile, such as an activity profile with a varying slope, to compensate for the inherent nonlinearities of catalyst utilization during operation of an electrochemical fuel cell. Desired variable catalyst activity profiles may be achieved, for example, by varying the catalyst loading across the MEA from inlet to outlet ports or by varying the surface area of the catalyst loading or by varying the surface area of the catalyst support elements.
摘要:
A fuel cell assembly includes first and second compression members. Two or more membrane electrode assembly (MEA) stacks are disposed between the compression members, each MEA stack having a positive and negative end. A first current collector is electrically coupled to a positive end of a first stack of the MEA stacks. A second current collector is electrically coupled to a negative end of a second stack of the MEA stacks. A current shunt is disposed between the compression members and electrically couples the MEA stacks.
摘要:
Flow field designs are provided, as well as flow field devices employing the subject flow field designs. A fluid distribution assembly is provided comprising a flow field device and a fluid transport layer disposed between the flow field device and a target area, where, for at least one finite non-zero flow rate and at least one use rate of an active component of the fluid in the fluid transport layer, lateral flux of the active component varies by no more than 35% through at least 90% of all overland portions of said fluid transport layer. In one embodiment, the flow field device comprises a flow field comprising a serpentine channel, comprising non-parallel sequential major segments. In a further embodiment, the angles between successive major segments of the serpentine channel vary progressively.
摘要:
A heatsink for use in injection molding, with at least one load-bearing path with a rearward segment, wherein at least a portion of at least one non-load-bearing, dynamic heat-transfer zone of the heatsink is laterally offset from the rearward segment of the load-bearing path.
摘要:
A novel metering valve having improved flow for delivery of an aerosol formulation is disclosed. Methods of delivering an aerosol formulation using a device comprising the novel metering valve are also disclosed.
摘要:
A flow field for an electrochemical cell such as a fuel cell is provided, having micro-flow channels having a width or depth of less than 800 &mgr;m, a pitch of less than 800 &mgr;m, or a proportion of inter-channel land area of less than 25%. The channels may further comprise micro-features within the channels. A flow field plate comprising the subject flow field is provided.
摘要:
Components that include catalyst layers used in membrane electrode assemblies (MEAs), and methods of making such components are described. The catalyst layers yield more uniform current distributions across the active area of the MEA during operation. The catalyst layers may have a uniform catalyst activity profile of a less active catalyst to achieve more uniform current density over the MEA active area. The catalyst layers may have a variable activity profile, such as an activity profile with a varying slope, to compensate for the inherent nonlinearities of catalyst utilization during operation of an electrochemical fuel cell. Desired variable catalyst activity profiles may be achieved, for example, by varying the catalyst loading across the MEA from inlet to outlet ports or by varying the surface area of the catalyst loading or by varying the surface area of the catalyst support elements.
摘要:
Components that include catalyst layers used in membrane electrode assemblies (MEAs), and methods of making such components are described. The catalyst layers yield more uniform current distributions across the active area of the MEA during operation. The catalyst layers may have a uniform catalyst activity profile of a less active catalyst to achieve more uniform current density over the MEA active area. The catalyst layers may have a variable activity profile, such as an activity profile with a varying slope, to compensate for the inherent nonlinearities of catalyst utilization during operation of an electrochemical fuel cell. Desired variable catalyst activity profiles may be achieved, for example, by varying the catalyst loading across the MEA from inlet to outlet ports or by varying the surface area of the catalyst loading or by varying the surface area of the catalyst support elements.