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Moyer C.J.,Colorado School of Mines | Moyer C.J.,Versa Power Systems | Sullivan N.P.,Colorado School of Mines | Zhu H.,Colorado School of Mines | Kee R.J.,Colorado School of Mines
Journal of the Electrochemical Society | Year: 2011

This paper reports the results of combined experimental and modeling studies of reversible solid-oxide cells. The tubular cells are fabricated using a Ni-YSZ (yttria-stabilized zirconia) fuel-electrode support, a dense YSZ electrolyte membrane, and a strontium-doped lanthanum manganate-YSZ composite air electrode. Experiments are designed to systematically vary gas-phase species partial pressures and operating temperatures. The fuels are mixtures of H 2, CO, H2O, CO2, and Ar. Performance is measured under anodic (fuel cell) and cathodic (electrolysis) polarization. The models consider reactive porous-media transport within the composite electrodes, thermal chemistry on Ni and YSZ surfaces, and charge-transfer chemistry. All chemistry is modeled with elementary reversible reactions. Close coupling between experimental measurements and model-based interpretation provides a basis for establishing reaction pathways and rates. In addition to advancing fundamental understanding, the resulting detailed reaction mechanisms are valuable for incorporation into predictive models that can be used for design and optimization of fuel-cell and electrolysis systems. © 2010 The Electrochemical Society.

Borglum B.,Versa Power Systems | Ghezel-Ayagh H.,Fuel Cell Energy, Inc
ECS Transactions | Year: 2013

Versa Power Systems (VPS) is a developer of solid oxide fuel cells (SOFCs) for clean power generation and was recently acquired by FuelCell Energy (FCE). FCE is a global leader in the design, manufacture and distribution of Molten Carbonate Fuel Cell (MCFC) power plants. From an economic perspective, MCFCs scale-up very well and as a result FCE's MCFC products are in the multi-megawatt size range. SOFCs are complementary because they scale-down well and hence are well suited to sub-megawatt applications. This paper highlights the status of VPS and FCE's SOFC technology in the areas of cell, stack and system development. © The Electrochemical Society.

Agency: Department of Defense | Branch: Defense Advanced Research Projects Agency | Program: SBIR | Phase: Phase I | Award Amount: 98.84K | Year: 2008

The purpose of the proposed solid oxide fuel cell (SOFC) development effort is to demonstrate the feasibility of achieving a high specific power (1000 W/kg) SOFC stack capable of operating both as a power generator and an electrolyzer while achieving high electrochemical efficiency (approximately 70%) and long operating life (one to two years). A SOFC stack achieving these performance characteristics enables the development of a regenerative power system with a system average specific energy of over 2000 W-hr/kg for use in a high altitude, long endurance (HALE) aircraft with multi-month endurance. Based on Versa Power Systems’ well-established SOFC technology baseline, the approach for demonstrating feasibility is based on deconstructing technical issues into deterministic engineering problems while avoiding fundamental changes to the technology baseline. The work encompasses a preliminary design of a high specific power stack, an empirical evaluation of innovative interconnect materials, and an empirical evaluation of the impact of electrolysis on component durability. Subsequent development will focus on the physical implementation of the components identified in Phase I, including ground-based functional stack and power system testing and eventual incorporation into a flight-test vehicle.

A high temperature, redox tolerant fuel cell anode electrode and method of fabrication in which the anode electrode is pre-conditioned by application of an initial controlled redox cycle to the electrode whereby an initial re-oxidation of the anode electrode is carried out at temperatures less than or equal to about 650 C.

Versa Power Systems | Date: 2011-01-14

The present invention relates to an apparatus for steam purging a solid oxide fuel cell stack. Purging the SOFC stack with steam has a physical flushing effect, removing carbon monoxide containing reformate and free oxygen gas from the anode area thereby reducing the potential for nickel oxide or nickel carbonyl formation.

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