Abstract:
A device and method to extract water from a moisture-rich fuel cell flowpath. A water transport unit is integrated into the fuel cell so that liquid water stagnation within flow channels and manifolds is reduced. In one embodiment, the device includes numerous flowpaths that include an active region and an inactive region. The water transport unit includes a hydrophilic member such that upon passage of a fluid with the excess water through the inactive region of the device flowpath and into the presence of the hydrophilic member, it absorbs excess water from the fluid.
Abstract:
A bipolar plate for a fuel cell is disclosed including a first unipolar plate having an active surface with a plurality of flowfield channels formed therein. The first unipolar plate further includes an inlet header disposed at a first end of the unipolar plate that is in communication with the active surface, and an outlet header disposed at a second end of the unipolar plate having an exhaust opening formed therethrough. A peripheral edge of the exhaust opening is chamfered and is also in communication with the active surface. The chamfered exhaust opening forms a water removal channel in the bipolar plate. A fuel cell stack including the bipolar plate is also disclosed.
Abstract:
A fuel cell and a method for manufacturing a fuel cell including a membrane electrode assembly that includes an ionically conductive member and an electrode disposed at the ionically conductive member. Further, the fuel cell includes an electrically conductive member or gas diffusion medium that includes a flow field formed of conductive particles dispersed in a binder.
Abstract:
A method of depositing a conductive material is described. The method includes: providing a plate selected from anode plates, cathode plates, bipolar plates, or combinations thereof, wherein the plate includes gas flow channels; providing a diffusion media in contact with the gas flow channel side of the plate to form an assembly; introducing a gaseous precursor of the conductive material into the assembly using a chemical vapor infiltration process; infiltrating the gaseous precursor into the diffusion media and gas flow channels of the plates; and depositing a coating of the conductive material on the diffusion media, the gas flow channels of the plate, or both. An assembly having a CVI conductive coating and a fuel cell incorporating the diffusion media having the CVI conductive coating are also described.
Abstract:
A fuel cell plate having a first plate having an inlet aperture and a second plate disposed against the first forming a conduit. The conduit has a continuous seam formed between the first plate and the second plate to facilitate a transport of water to the outlet aperture. The plates can include various indentations and protuberances that form portions of the conduit. The fuel cell plate is well suited for use in a vehicle fuel cell stack for reducing water retention in a fuel cell without increasing the number of required components and fabrication cost of the fuel cell plate.
Abstract:
A method for depositing a hydrophilic coating on flow field plates or bipolar plates and manifolds in a fuel cell stack after the stack is assembled. The method includes preparing a solution that contains hydrophilic nano-particles suspended in a suitable solvent. The cathode and anode inlet and outlet manifolds and the cathode and anode flow channels are filled with the solution. The solution is then pumped out of the stack using, for example, a stream of nitrogen. The stack is allowed to dry, using heat if desirable, to provide a film of the nano-particles formed on the anode and cathode flow channels and manifolds within the stack.
Abstract:
One embodiment of the invention comprises a fuel cell bipolar plate comprising a substrate comprising a first face, a reactant gas flow field defined in the first face, the reactant gas flow field comprising a plurality of lands and channels, and a plurality of microgrooves formed in the first face.
Abstract:
Methods and materials to improve water management in a fuel cell by microtexturing fuel cell elements, including the separator plate and/or the gas diffusion media. A method of manufacturing a fuel cell includes a separator plate and/or a gas diffusion media that are microtextured. Selective ablation of material and stamping can impart microtexturing, where the microtexturing facilitates water management in the fuel cell.
Abstract:
A device and method to extract water from a moisture-rich fuel cell flowpath. A water transport unit is integrated into the fuel cell so that liquid water stagnation within flow channels and manifolds is reduced. In one embodiment, the device includes numerous flowpaths that include an active region and an inactive region. The water transport unit includes a hydrophilic member such that upon passage of a fluid with the excess water through the inactive region of the device flowpath and into the presence of the hydrophilic member, it absorbs excess water from the fluid.
Abstract:
A method of depositing a conductive material is described. The method includes: providing a plate selected from anode plates, cathode plates, bipolar plates, or combinations thereof, wherein the plate includes gas flow channels; providing a diffusion media in contact with the gas flow channel side of the plate to form an assembly; introducing a gaseous precursor of the conductive material into the assembly using a chemical vapor infiltration process; infiltrating the gaseous precursor into the diffusion media and gas flow channels of the plates; and depositing a coating of the conductive material on the diffusion media, the gas flow channels of the plate, or both. An assembly having a CVI conductive coating and a fuel cell incorporating the diffusion media having the CVI conductive coating are also described.