FuelCellsWorks

QuantumSphere’s Advanced Nanoscale Materials Integrated With Complex Hydrides Exceed U.S. Department of Energy’s 2010 Targets, Which Could Enable Safe and Economical Hydrogen Storage for Portable Power Applications

SANTA ANA, Calif.– QuantumSphere, Inc. and the University of South Florida today announced that they have exceeded the 2010 Department of Energy (DOE) goals for solid state hydrogen storage. Achieving these goals fosters the commercialization of safe, lightweight fuel storage for portable, stationary power, and transportation applications.

In a two year materials discovery program funded by QuantumSphere, Inc., Professor Elias Stefanakos, director of the Clean Energy Research Center (CERC) at the University of South Florida, and Research Associate Dr. Sesha Srinivasan (currently an assistant professor at Tuskegee University), have developed complex metal hydrides doped with QuantumSphere’s nano-Nickel particles produced by its patented manufacturing process. These materials have a 6-8 wt% reversible hydrogen capacity below 150 degrees C. This compares to the 6 wt% system efficiency target set by the DOE, as this is believed to be the threshold at which hydrogen can be economically stored as a solid. These results have been confirmed independently by the Southwest Research Institute (SWRI) and the National Institute of Standards and Technology (NIST).

Hydrogen is the most abundant element in the universe and has the highest energy content — three times more than gasoline on a per-pound basis. Unfortunately, it is a gas at room temperature and typically stored in pressurized tanks at 5,000 to 10,000 psi. This presents handling, packaging, safety, and storage challenges and increases the size and weight of power systems. Alternatively, hydrogen stored in the solid state requires lower pressure (100 to 1,000 psi), is safer to handle, and has a simplified, lightweight tank design. However, prior to the QuantumSphere and University of South Florida breakthrough, there had been limited success in discovering solid-state materials capable of effectively storing hydrogen reversibly at practical operating temperatures. This has limited the deployment of hydrogen as a fuel carrier for portable electricity generation.

“The high-performance materials designed by QuantumSphere and CERC enables high energy density, solid-state, reversible hydrogen storage systems and will foster the commercialization of hydrogen fuel cells,” said Prof. Stefanakos. “Fulfilling the need for lightweight storage is especially important in early market applications such as uninterruptable power supplies and unmanned systems.”

“We are impressed with the high caliber of research performed at the University of South Florida,” said Dr. Kimberly McGrath, director of fuel cell research at QuantumSphere. “We are focused on demonstrating the value of these new materials at the system level for power applications in the 1-10kW range.” Dr. McGrath added, “Furthermore, the fundamental nanomaterials knowledge we have gained has directly translated into the development of higher capacity materials for nickel-metal hydride batteries.”

A summary of the research and full technical whitepaper can be found at: www.qsinano.com.

About the Clean Energy Research Center

The mission of the University of South Florida’s Clean Energy Research Center (CERC) is to develop, evaluate, and promote commercialization of new environmentally clean energy sources and systems such as hydrogen, fuel cells, solar energy conversion, biomass utilization, etc., that meet the needs of the electric power and the transportation sector through multi-disciplinary research, technical and infrastructure development, and information transfer. The Center supports regional economic development of manufacturing and high technology business, in conjunction with the National goals of improving our global competitiveness and technology leadership. The development of hydrogen storage materials has received significant financial support over the past three years, from the U.S. Department of Energy through a cross-cutting DOE grant awarded to Drs. Elias Stefanakos and Yogi Goswami. For additional information, please visit http://cerc.eng.usf.edu/.

About QuantumSphere

QuantumSphere, Inc. (QSI) leverages its award winning advanced catalyst materials and process chemistry expertise to develop, manufacture, and license solutions for a broad range of portable power and clean-tech applications. The company’s proprietary products, available in commercial volume, are used by industry leading companies to lower costs and enable breakthrough performance in established multi-billion dollar and high-growth markets such as batteries and fuel cells for portable power, emissions reduction for transportation and stationary power applications, and chemical synthesis of ammonia for food production.

Founded in 2002, QSI’s mission is to reduce dependence on non-renewable energy sources and provide near-term, revolutionary, portable power and clean-technology products. QSI achieves this through continuous innovation and refinement of its proprietary catalyst materials, unique process chemistries, high-performance electrode systems, and other advanced technology platforms. Please turn up your speakers and click here to learn more about QuantumSphere or visit our website at www.qsinano.com.

The plate reactor in the laboratory used to cultivate algae guarantees optimal light management. (© KIT, Florian Lehr)

Hydrogen (H2) produced from water has great potential to be an environmentally friendly energy carrier of the future. However, the future application of hydrogen and other CO2-neutral sustainable fuels also requires the development of production methods that can contribute to the energy supply of tomorrow. Some unicellular green algae and cyanobacteria use light to break up water into hydrogen and oxygen. In cooperation with eight partners, KIT scientists are currently working on the development of highly efficient methods for hydrogen production from microalgae. The BMBF is funding the “HydroMicPro” project with a total of 2.1 million euros.

The “H2 from microalgae: With cell- and reactor design towards economically feasible production” (HydroMicPro) project is being coordinated by Professor Clemens Posten from the KIT Institute of Engineering in the Life Sciences and involves several universities, research institutions and companies. The German Federal Ministry of Education and Research (BMBF) is supporting the project for the next three years with funds from the “Grundlagenforschung Energie 2020+” programme (Basic Energy Research 2020+). “The HydroMicPro project is focused on the development of an affordable, highly efficient production process with optimised biology and process technology in order to create the prerequisites for the production of large amounts of hydrogen,” said Posten.

The goal of the project is the economic production of hydrogen from microalgae
The objective of the project is to achieve costs of around 25 euros per square metre of soil area for the cultivation of algae. The partners from science and industry will be working on research topics such as photobioreactors, gas separation using membrane methods, biological sensor technologies for cellular oxygen, the biotechnological optimisation of algae as well as system integration. In addition, they will carry out practical field tests and test the application of the hydrogen production method in the aerospace industry, as well as doing environmental and cost analyses. Besides the KIT (northern and southern campus), the project also involves the University of Bielefeld, the Max Planck Institute for Molecular Plant Physiology in Potsdam, the University of Potsdam, Ehrfeld Mikrotechnik BTS GmbH (EMB) based in Wendelsheim, IGV GmbH in Nuthetal as well as OHB-System AG based in Bremen.

The KIT’s microalgae research group will be responsible for developing an optically structured photobioreactor for the production of hydrogen. Initially, it is planned to enlarge the inner surfaces of the reactor in the hope that, combined with very thin cell layers, this will lead to high efficiency and enhanced cell concentrations. In addition, the algae will be exposed to carbon dioxide through membranes in order to reduce the use of auxiliary energy. This step also involves the KIT’s Engler Bunte Institute. The reactor will be developed in two stages. The initial stage will focus on achieving high biomass production, which is also required for the production of other algal substances. The second step will focus on optimising the hydrogen production system.

• Micro-tubular solid oxide fuel cells are integrated to realize prototype modules capable of generating powers of 50 to 200 W.
• An output power of over 50 W (volumetric power density: 2 W/cm³) with a power generation efficiency of over 40% is obtained using the module comprising 90 cells.
• The developed module integration technology offers good prospects of realizing higher power generation capacity of up to several hundred watts.

Summary

The Functional Assembly Technology Group (Leader: Yoshinobu Fujishiro), Advanced Manufacturing Research Institute (Director: Norimitsu Murayama) of the National Institute of Advanced Industrial Science and Technology (AIST) (President: Tamotsu Nomakuchi), Fine Ceramics Research Association (President: Taro Kato) and NGK Spark Plug Co., Ltd. (President: Norio Kato) (FCRA-NGK), and Toho Gas Co., Ltd. (Toho Gas) (President: Taku Saeki) have developed highly integrated high-performance micro-tubular solid oxide fuel cell (SOFC) modules that would broaden the range of SOFC applications.

The existing applications of SOFCs are limited because the cells are operated at high temperatures of over 800°C. It has been desired to realize SOFC modules capable of rapid (start-and-stop) operation. In this study, we have developed SOFC modules generating several tens to hundreds of watts of power, which are compatible with various system requirements. Power generation tests were carried out to examine the connection of gas manifolds, current collections, and various characteristics of the modules. The tested module consisting of two integrated micro-tubular SOFC units (a total of 90 cells) produced an output of over 50 W with a power generation efficiency of over 40% and a volumetric power density of 2 W/cm³. Further, a 200-W-class module was built by assembling eight integrated units. Thus, the basic fabrication and evaluation techniques for larger modules generating powers of up to several hundred watts have been established (see Figure below). The applicability of the SOFC modules to auxiliary power units (APUs) and small-sized cogeneration systems will be tested using the 200-W-class module.

Highly integrated micro-tubular SOFC module

The study is a part of the “Advanced Ceramic Reactor” project of the New Energy and Industrial Technology Development Organization (NEDO) and the result will be reported at the 22nd Fall Symposium of the Ceramic Society of Japan, to be held at Ehime University on September 16, 2009, and at the 11th International Symposium on SOFCs, to be held in Vienna, Austria, on October 6, 2009.

Social Background for Research

Many types of fuel cells have been developed in attempts to achieve high power generation efficiency and greatly reduce CO₂ emissions, which cause global warming. Among these fuel cells, SOFCs that consist of ceramic components exhibit the highest efficiency. Since SOFCs, unlike other types of fuel cells, are operated at high temperatures (800–1000°C), exhaust heat can be used for fuel reforming and hot water storage, and the overall energy efficiency of the system can be very high. Further, it has been confirmed that SOFCs exhibit greater long-term stability than other types of fuel cells. However, because the SOFCs are operated at high temperatures, their applications have been limited to power generation systems in which the thermal cycle and load variation can be kept small. Therefore, SOFCs for rapid start-and-stop operation at temperatures below 650°C have been desired so that they can be used in a wide range of applications such as domestic dispersed power sources, power sources for mobile electronic devices, and APUs in automobiles. In such circumstances, micro-tubular SOFCs were proven to show a great promise for realizing rapid start-and-stop operation. One of the problems, however, was the difficulty in integrating these tubular cells to realize small, highly efficient SOFCs generating powers ranging from several watts to several kilowatts, for which there is a great demand in industry (Fig. 1).

Fig. 1 Trends in fuel cell development and demand for small-scale SOFCs

History of Research

As part of a NEDO project, the Advance Ceramic Reactor Project (FY2005–FY2009), AIST, FCRA-NGK, and Toho Gas have collaborated to realize SOFCs that satisfy requirements such as operation at temperatures below 650°C, high power output, and rapid start-and-stop operation. The collaboration has developed high-performance micro-tubular SOFCs capable of rapid start-up, whose diameters are in the millimeter or sub-millimeter range. Techniques have been established to fabricate an integrated unit (cube), which is of the size of a sugar cube and can generate powers of over 2 W/cm³ at the low temperature of 550°C (press release on March 29, 2007). To improve the performance of integrated units and modules, technologies for upgrading micro-tubular SOFCs were further studied, and one of related reports was published in the US journal “Science” (August 14, 2009).

For practical applications of systems with the high-performance micro-tubular SOFCs, it was considered necessary to increase the scale of integration, and establish and verify integration techniques for realizing arbitrary electrical connections to satisfy output requirements, as well as module technologies including manifold connections. AIST, FCRA-NGK, and Toho Gas have developed techniques for integrating the micro-tubular SOFCs and fabricating prototype modules. We have also evaluated power generation capabilities to prove the effectiveness of the adopted fabrication techniques. AIST assumed the responsibility of evaluating the basic performance of each module element; on the basis of this result, FCRA-NGK designed and fabricated modules, and Toho Gas evaluated the completed modules.

Details of Research

In this study, micro-tubular SOFCs, which are inherently capable of rapid start-and-stop operation, are highly integrated. Gadolinia-doped ceria and scandia-stabilized zirconia were selected for an electrolyte of the cell, both of which are excellent ion-conducting materials. The power generation performance was examined with a 50-W-class module. To be more precise, a module is assembled using multiple integrated units of the 15-to-30-W class (3 in parallel, 9–15 in series) comprising components with excellent size accuracy to meet a target power output. To realize a 50-W-class module, two integrated units (Fig. 2), each consisting of 3 micro-tubular SOFCs in parallel and 15 in series, are connected in parallel (the module contains 90 cells). This module is proved to generate an output power of over 50 W with a power generation efficiency of over 40% and a power per unit volume of 2 W/cm³ (per integrated unit; Fig. 3). It is also confirmed that even higher output power can be obtained under lesser fuel utilization rate. Further, a 200-W-class module has been assembled and is now being evaluated. Although the 200-W-class module comprises eight integrated units and is complex, the completion of the power generation unit with gas manifolds and a current collecting structure increases the prospects for higher power outputs, and indicates that we have taken a significant step forward to a wider range of SOFC applications.

Fig. 2 Development of small, high-efficiency SOFCs and modules

Fig. 3 Power generation test results for 50-W-class modules

The degree of the integration per unit volume (electrode area) in the SOFC modules developed in this study is the highest level, and the developed technologies can be applied to realize smaller and more powerful energy sources. Since the basic component of the modules, i.e., an integrated unit, can generate a volumetric power density of 2 W/cm³, the present technology is proved to be effective for the fabrication of highly integrated micro-tubular SOFC modules.

Future Schedule

The developed micro-tubular SOFC module technology will help accelerate the expansion of applications of SOFCs, module volume ranging from several ten cm³ (applications involving power generation of several tens of watts, such as power sources for mobile electronics devices) to several thousand cm³ (of several kilowatts, such as domestic power sources and APUs of automobiles).

We will further improve the cell and module structure, perform tests under various operating conditions, and improve the module performance with the aim of developing high-performance SOFC modules that are robust to thermal shock, capable of rapid start-up, and readily compatible with a variety of system requirements.