A Feasibility Study of Ribbon Architecture for PEM Fuel Cells

Abstract

The feasibility of an alternative fuel cell architecture, called a ribbon membrane electrode assembly (MEA), is demonstrated for low-temperature polymer electrolyte membrane (PEM) fuel cells used in portable power applications by comparing it to a traditional bipolar “stack” architecture. A ribbon MEA consists of adjacent PEM cells sharing a common gas diffusion layer to allow for lateral electrical current flow and an integral gas-tight, conductive interconnect/seal, where adjacent cells meet to prevent reactant gas leakage. The resulting lateral arrangement of MEAs can be used to supply all MEAs simultaneously instead of individual bipolar plates with flow fields for a stack. A pair of two-cell ribbon MEAs, with and without an interconnect/seal, were designed, prototyped, and sealed by thermal pressing. The MEAs were clamped in a two-piece box fixture to provide reactant gases on the anode and cathode sides, hooked to a fuel cell (FC) test stand and yielded an open circuit voltage (OCV) of 1.43 V with an interconnect/seal and 0.6 V without. A two-cell bipolar stack PEMFC with identical MEA specifications had an OCV of 1.86 V. Polarization curves for the ribbon MEA with interconnect/seal showed the sensitivity of performance to clamping pressure and positioning of the copper current collectors. The ribbon MEA polarization curve was also shifted downward by 0.42 V as compared with that of the traditional stack, and suspected causes (e.g., gas leaking) are attributable to the nonoptimal test fixture design. Hence, the ribbon MEA architecture is shown to be feasible. Future work suggested includes improvements to the test fixture design, development of automated manufacturing capabilities for high volume production, and demonstration of a multicell (>2) ribbon MEA PEMFC design.

Key findings

• ▸Ribbon MEA with interconnect/seal achieves higher OCV (1.43 V) compared to without interconnect/seal (0.6 V)
• ▸Ribbon MEA outperforms traditional bipolar stack PEMFC in terms of OCV (1.43 V vs 1.86 V)
• ▸Polarization curves show improved performance for ribbon MEA with interconnect/seal

Keywords

Identifiers

DOI

10.1115/1.4001758

Journal

Journal of Fuel Cell Science and Technology

Year

2010