DOE 2014 Hydrogen and Fuel Cell Progress Report highlights substantial progress

13 November 2014

The US Department of Energy (DOE) Fuel Cell Technologies Office (FCTO) has posted the 2014 edition of its annual Hydrogen and Fuel Cells Program Annual Progress Report—a nearly 1,000-page document. The report summarizes the reports provided each year by projects funded by DOE’s Hydrogen and Fuel Cells Program and offers additional information about recent Program accomplishments.

The Program engages in research, development, and demonstration (RDD) of critical improvements in hydrogen and fuel cell technologies, as well as other activities to overcome obstacles to commercialization. The Program integrates basic and applied research, technology development and demonstration, and other supporting activities. Over the past year, said Dr. Sunita Satyapal, Director, FCTO, “the Program made substantial progress toward its goals and objectives.”

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The report is comprehensive, reflecting the range of work supported by the DOE: hydrogen production, delivery and storage; the fuel cells themselves (spanning catalyst and membrane development through testing); manufacturing RD; technology validation; safety, codes and standards; market transformation; systems analysis; and small business innovation research.

Fuel cells. In his overview of the activities of the fuel-cell subprogram, DOE Fuel Cell Program Manager Dr. Dimitrios Papageorgopoulos, highlighted the development of a new platinum-nickel (Pt-Ni) catalyst with unprecedented activity.

Scientists at Lawrence Berkeley National Laboratory (LBNL) had initially created Pt-Ni crystalline polyhedra particles that were left under ambient conditions in a solvent exposed to air for two weeks. Surprising changes in the structure and composition were noted—the particles had spontaneously dealloyed into a more Pt-rich alloy and transformed into hollow nanoframe structures. Recognizing the potential relevance of these new structures for catalysis, the LBNL researchers teamed up with electrochemists at Argonne National Laboratory (ANL). ANL optimized the synthesis process, resulting in a catalyst that can be prepared in only a few hours with an activity that outstrips all previous fuel cell catalysts in
ex situ testing.

Encapsulating a protic ionic liquid inside the nanoframe catalyst resulted in a further increase in activity, yielding more than 30X the mass activity of a conventional platinum catalyst in rotating disk electrode (RDE) testing.

The nanoframes showed no decrease in activity after 10,000 cycles of accelerated stress testing, demonstrating high durability. ANL is now scaling up synthesis of the catalyst for testing in a fuel cell, a critical step to assess viability in practical applications.

A new catalyst synthesized in 2014, which consists of a platinum-nickel alloy nanoframe covered by a thin platinum skin, has a performance more than 30 times higher than conventional platinum on carbon catalysts. Source: DOE. Click to enlarge.

Also in 2014, a team led by General Motors In 2014, reported achieving good durability of high-current performance with PtCo and PtNi dealloyed catalysts, which have already met DOE targets for mass activity and durability of mass activity. These catalysts achieved the same H₂/air fuel cell performance as a 0.4 mgPt/cm² electrode, but with only one-fourth the PGM (platinum-group metal) loading.

The performance improvements were confirmed in a full-active-area automotive stack. Up to 60,000 cycles between 0.6 and 0.925 V were performed with only 20 mV loss at 1.5 A/cm².

Papageorgopoulos also highlighted the work of a new project begun in 2014 on advancing the performance and durability of membranes under hot and dry operating conditions by improving and combining components developed under earlier
projects.

Specifically, perfluoroimide acid ionomers previously developed have met many performance and durability targets, but ionomer improvement and membrane
thickness reduction are required to simultaneously meet all DOE membrane targets. Modifications to the ionomer chemical structure, combined with incorporation of inert
nanofiber supports developed by Vanderbilt University, enabled the new membranes to meet chemical and mechanical durability targets while approaching all membrane resistance targets.

Finally, he noted the improvements in membrane electrode assemblies (MEAs) containing PtNi nano-structured thin film catalysts. These have enabled performance improvement at high current densities, resulting in PGM total content levels as low as 0.16 g/kW at 150 kPa_abs. This measurement was obtained at a high operating temperature of 90 °C and voltage of 0.69 V, conditions that satisfy the DOE heat rejection target, Q/ΔT ≤1.45.

When compared to PGM total content measured at 0.69 V in previous years, this year’s results mark a 25% and a 6% improvement since 2012 and 2013, respectively. Further development is required to achieve DOE’s target level of 0.125 g/kW, and to simultaneously meet durability targets.

2015 plans. In FY 2015, the Fuel Cells sub-program will continue RD efforts on fuel cells and fuel cell systems for diverse applications, using a variety of technologies (including PEM and alkaline membrane fuel cells) and a range of fuels (including hydrogen, natural gas, and bio-derived renewable fuels).

The sub-program will continue its support for RD that addresses critical issues with electrolytes, catalysts, electrodes, and modes of operation, with an emphasis on cost reduction and durability improvement. The sub-program will also continue its emphasis on science and engineering with a focus on component integration at the cell and stack level, as well as on integration and component interactions at the system level.