Thin film MEA structures for fuel cell and method for fabrication

摘要

The current invention provides a fabrication method for large surface area, pinhole-free, ultra thin ion conducting membranes using atomic layer deposition on inexpensive sacrificial substrates to make cost effective, high performance fuel cells or electrolyzers. The resultant membrane electrode assembly (MEA) enables significant reduction in resistive losses as well as lowering of the operating temperature of the fuel cell. The invention further provides a method to deposit 3-dimensional surface conformal films that may have compositional grading for superior performance. In addition, the invention provides decoration and modification of electrode surfaces for enhanced catalytic activity and reduced polarization losses. The method of the current invention enables the MEA structure to be fabricated from the anode side up or the cathode side up, each with or without an incorporated anode current collector or cathode current collector, respectively.

主权项

1. A method of fabricating a membrane electrode assembly (MEA) structure comprising:
a. providing a sacrificial support layer, wherein said sacrificial support layer comprises a removable material; b. bonding a continuous non-planar current collector sheet or foil to said sacrificial support layer, wherein said continuous non-planar current collector sheet or foil comprises through-hole features with vertical walls; c. using atomic layer deposition (ALD) to deposit a first 3-dimensional non-planar conformal electrode layer (first electrode layer) to said continuous non-planar current collector sheet or foil and to said sacrificial support layer, wherein said first electrode layer uniformly and conformally coats the top surface of said continuous non-planar current collector and the vertical walls of said through-hole features in said continuous non-planer current collector sheet or foil and an exposed surface of said sacrificial support layer; d. using said (ALD) to deposit a pinhole-free non-planar electrolyte layer on said first electrode layer, wherein said pinhole-free non-planar electrolyte layer uniformly and conformally coats the vertical walls and top surface of said first electrode layer to form a 3-dimensional non-planar pinhole-free electrolyte layer; e. using said (ALD) to deposit a second 3-dimensional non-planar conformal electrode layer (second electrode layer) on said 3-dimensional non-planar pinhole-free electrolyte layer, wherein said second electrode layer uniformly and conformally coats the vertical walls and top surface of said 3-dimensional non-planar pinhole-free electrolyte layer; and f. removing, using an appropriate solution process, said sacrificial support layer from said continuous non-planar current collector sheet or foil; wherein after forming the MEA, depositing a third planar electrode layer contacting an underside of the continuous non-planar current collector sheet or foil and the first electrode, and said continuous non-planar current collector sheet or foil is enveloped in said electrode layer and said third electrode layer.