Interest in graphite has recently soared with the emergence of electric vehicles using Li-Ion batteries, leading to a surge in research and development. Many other uses are being researched, some of which are experimental and have a long road ahead to commercialization.
Listed below are links to research findings, some of which have been commercialized and licensed for manufacture.
The Oak Ridge National Laboratories, (ORNL http://www.ornl.gov) funded by the US Department of Energy is one of the leading centers of research in Graphite. Some significant developments at ORNL are:
Light emitting diode (LED) lamps are being increasingly used in lighting applications from decorative Christmas lights, to street lighting and in automobiles to name a few. Cooling the lamp has been a challenge. Each 10 degree reduction in temperature doubles the life of the lamp. Graphite foam technology developed by James Klett and colleagues of ORNL's Materials Science and Technology Division addresses the issue. The technology has been licensed to LED North America who will use the graphite foam to passively cool components in LED lamps. LED North America specializes in providing LED lighting products for municipal, commercial and industrial applications.
The biggest advantage is cost savings as James Klett states: "While this technology will reduce temperatures and increase the life of the LED lighting systems, the greatest long-term benefit will be the cost savings to municipalities from reduced fixture replacement and maintenance," Klett says.
One of Lockheed Martin Corporation's highest profile programs in the Open Innovation Program is Ocean Thermal Energy Conversion (OTEC) which uses temperature differences in the world's oceans to create energy. Addressing the need to develop alternate sources of renewable energy, Johnnie Cannon, who heads up ORNL's Global Security Directorate's collaboration with the program, says its goal is to develop "disruptive" technologies that leapfrog the competition, rather than making gradual, predictable progress.
Given the state of current OTEC technology, a commercial scale OTEC power plant would require at least 20 very large heat exchangers. Graphite foam heat exchangers developed by James Klett and his research team at ORNL brings in the “disruption” to leap frog development of efficient heat exchangers. Graphite foam combines a tremendous amount of surface area with a high capacity for conducting heat, enabling these heat exchangers to improve the performance of standard thermally conducting units while reducing their size and cost. Making heat exchangers twice as effective means an OTEC power plant could cut the size of its heat exchangers in half, shrinking the capital expenditure for the plant and making OTEC a much more practical green energy alternative. Alternatively, the same size heat exchangers could produce twice the power for the same cost. Graphite foam's tremendous surface area and high capacity for conducting heat boost the performance of heat exchangers while reducing their size and cost.
James Klett of ORNL, highlights the enormous advantages and states: "There are several compelling advantages to the system," says Klett. "First, it produces totally green energy; there are no by-products. It's also very much like geothermal, solar or wind power in that it does not take any fossil fuel to drive it, so costs are limited to construction and maintenance." In addition, Klett is particularly emphatic about the availability of OTEC power. He notes that consumers don't always understand that the only kind of "green" energy that is currently available as "base power"—power that is available 24 hours a day, 7 days a week—is geothermal. "With other renewables," he says, "when the wind stops, you don't have power. If it's a cloudy day, you don't have power. Even hydroelectric power is at the mercy of fluctuating water levels. OTEC can actually be used for base power." Estimates suggest that, in tropical latitudes, OTEC has the potential to generate 3 to 5 terawatts of power without affecting the temperature of the ocean or the world's environment. "That's more than the electric generating capacity of this country," he says. "If we can supply a large fraction of our base power needs with green energy, we can revolutionize power generation."
In the 1940s Eugene Wigner correctly predicted that neutron irradiation of graphite would cause it to swell. By controlling the orientation of graphite's crystalline grains, ORNL's Walt Eatherly, Ray Kennedy, and Fred Jeffers developed the award-winning GraphNOL, which was commercialized in the 1980s. This graphite, which resists radiation damage and withstands extreme thermal shock and stress, has been used in missile nose cones.
Subsequently, various researchers at ORNL developed technologies and processes to use graphite derivatives for applications in vehicles, electronic, space and fuel cells.
The discovery of Graphite foam by James Klett at ORNL lead to many innovative applications to improve efficiency in various industries from automotive – radiators, coolant for braking systems and even as an anode in Li-Ion batteries.
A Pebble Bed Reactor ("PBR") is a small, modular nuclear reactor. Uranium is embedded in graphite balls the size of tennis balls. Pebble bed reactors have lower capital operating costs compared to traditional reactors. The United States, Germany and South Africa all experimented with Pebble Bed Reactors, but abandoned the projects due to cost overruns. China is now building the first prototype reactor and if successful plans to build to more by 2020. Each Pebble Bed Reactor is estimated to require 300 tonnes of graphite at start up and subsequently 60 to 100 tonnes annually to operate. West Virginia University researchers estimate that the United States will install up to 500 new 100 GW reactors by 2020. These reactors will require approximately 400,000 tonnes of graphite which is equal to the current global production of flake graphite excluding the requirement from the rest of the world for reactors, Li-Ion batteries and other applications.Further reading: A Radical Kind of Reactor – NY Times, Pebble Bed Reactor – Wikipedia