As part of the DOE-funded FreedomCAR program, Sandia’s Power Sources Technology Group is researching ways to make lithium-ion batteries longer-lived and safer. The research will lead to these batteries being used in new hybrid electric vehicles (HEVs) in the next five to 10 years.
“Batteries are a necessary part of hybrid electric-gasoline powered vehicles and someday, when the technology matures, will be part of hybrid electric-hydrogen fuel cell powered vehicles,” says Dan Doughty, manager of Advanced Power Sources Research and Development Dept. 2521. “Current hybrid vehicles use nickel-metal hydride batteries, but a safe lithium-ion battery will be a much better option for the hybrids.”
He notes the lithium-ion battery has four times the energy density of lead-acid batteries and two to three times the energy density of nickel-cadmium and nickel-metal hydride batteries. It also has the potential to be one of the lowest-cost battery systems.
Dan’s department receives about $1.5 million a year from the FreedomCAR program to improve the safety, lengthen the lifetime, and reduce costs of lithium-ion batteries.
The FreedomCAR program, initiated by President Bush in 2002, focuses on developing hydrogen-powered electric vehicles to free the US from dependence on foreign oil supplies. Five national laboratories — Sandia, Argonne, Lawrence Berkeley, Idaho, and Brookhaven — are involved in the program, each researching different aspects of making hybrid electric-hydrogen vehicles a reality.
Dept. 2521’s FreedomCAR work centers on the areas of battery abuse tolerance and accelerated lifetime prediction, with abuse tolerance receiving most of the focus.
“We want to develop a battery that has a graceful failure — meaning that if it’s damaged, it won’t cause other problems,” Dan says. “We have to understand how batteries fail and why they fail.”
The technical goal is to comprehend mechanisms that lead to poor abuse tolerance, including heat- and gas-generating reactions. Understanding the chemical response to abuse can point the way to better battery materials. But, Dan says, there is no “magic bullet” for completely stable lithium-ion cells.
“Fixing the problem will come from informed choices on improved cell materials, additives, and cell design, as well as good engineering practices.”
Work in abuse tolerance is beginning to shed light on mechanisms that control cell response, including effects of the anode and cathode, electrolyte breakdown, and battery additives.
The other area of work, accelerated life test, involves developing a method to predict lithium-ion battery life.
Empirical and mechanistic
“We have two approaches in our research — the empirical model and the mechanistic model,” Dan says. “The empirical model generates life prediction from accelerated degradation test data, while the mechanistic model relates life prediction to changes in battery materials. Our approach provides an independent measure of battery life so we don’t have to rely on what battery manufacturers tell us.”
Improved abuse test procedures developed at Sandia have led to lithium-ion test standards that the battery team has developed and recently published in a Sandia research report (SAND2005-3123). Dan anticipates that the Society of Automotive Engineers will soon adopt these test procedures as national standards, just as they adopted in 1999 (SAE J2464) the abuse test procedures that Sandia developed for Electric Vehicle batteries (SAND99-0497).
“There has been substantial progress in making batteries more tolerant to abusive conditions,” Dan says. “It won’t be long before these batteries will be used in gasoline-electric hybrid vehicles. And the great thing is this technology will be able to transfer over to the electric-hydrogen fuel cell powered hybrid vehicles of the future.”
Battery team members: Dan Doughty, J. Anthony (Tony) Romero, Brad Hance, Pete Roth, Dave Johnson, Lori Davis, Jill Langendorf, and Herb Case (all 2521). -- Chris Burroughs
Jeff Nelson (6218), manager of the CRADA, says the agreement is one of Sharp’s first interactions with a US laboratory.
Jeff says Sandia brings novel membrane and catalyst capabilities to the fuel cell project while Sharp brings extensive system and application-level experience.
“Our hope is that we’re successful and that success could expand our collaboration into solar photovoltaics and other areas,” he says.
The broader partnership between Sandia and Sharp will focus on energy technologies, specifically photovoltaics and fuel cells. It will involve research and development of Sharp’s solar photovoltaic technologies, including tests and improvements on reliability, durability, calibration of solar modules, inverters, and other advanced applications.
Sharp is the largest producer of solar photovoltaic modules in the world.
Chris Cornelius (6245), principal investigator for the CRADA, says Sandia will work with Sharp on the development of technologies for direct methanol fuel cells.
“Our research team and Sharp Corporation will bring together our materials and engineering skills to develop technologies that will impact methanol-based fuel cells,” Chris says.
“Sandia can apply its extensive materials capabilities to help Sharp bring new products to the market, and Sharp with its extensive electronics and manufacturing expertise will assure the development of commercial mobile power technology that is important for many applications, including portable power and distributed sensor networks,” Jeff says.
Sandia’s immediate focus is on portable power applications, such as the use of direct methanol fuel cells to power consumer electronics like laptops, cell phones, and PDAs.
Sharp has asked Sandia to fabricate fuel cells using Sandia’s proprietary membranes and catalysts. Members of Depts. 6245, 1823, and 1815, along with researcher Akimasa Umemoto from Sharp, have begun designing the materials and membrane electrode assemblies for Sharp’s specific application target. They will fabricate and test the fuel cells during the 12- to 18- month project under conditions relevant for Sharp’s applications.
The Sandia research team members for this project are Cy Fujimoto, Mike Hickner (both 6245), Bill Steen (1823), Eric Coker (1815), and Chris Apbeltt (1723).
Jeff acknowledged the assistance of Sandia’s technology transfer group in developing the CRADA, including Gary Jones, Vic Weiss, and Sherry Anderson.
“Gary and his team were instrumental in helping us navigate through many of the challenging issues associated with putting together a CRADA with a non-US company,” Jeff says.The arrangement was brokered by the New Mexico Economic Development Department following Gov. Bill Richardson’s meeting with Sharp’s executives in Tokyo.
By Will Keener
The Stone Age didn’t end for lack of stones and the Petroleum Age isn’t likely to end for lack of petroleum. That was the message of Steve Koonin, chief scientist for BP, plc, speaking to a nearly full house at Sandia’s Steve Schiff Auditorium in December. “We are not running out of oil any time soon,” he said.
His talk, the final one in a series of distinguished lecturers for 2005 presented by the Geosciences and Environment Center, was carried live on streaming video to another 1,100 Sandians.
Koonin, who earned his doctorate at MIT and served as provost at Caltech until moving to BP in 2004, alluded jokingly to an earlier talk at Sandia/California’s Combustion Research Facility (Lab News, Dec. 9, page 3.) At that talk, Paul Roberts, author of The End of Oil, gave his perspective on the future. Although Roberts’ message that a new revolution in energy is beginning seems opposite of Koonin’s, in fact the two speakers agreed on much of what lies ahead.
Signing on with one of the largest multinational energy companies in the world, Koonin was assigned the job of mapping a long-range technology strategy for BP (formerly British Petroleum). He took about a year to look at mounds of data, establish limiting factors that impact technology development, and predict the energy mix of the future. He identified population growth, supply security and challenges, and environmental constraints as the key factors affecting technology.
A physicist by training, Koonin cites a number of reasons for expecting petroleum’s continued dominance of the energy market, including substantial petroleum reserves and the “energy density” of petroleum.
Added to 41 years of known oil reserves and 67 years of gas reserves are other petroleum fuel forms extending the reach of the oil era. An additional 200 years of coal reserves allow for even more far-reaching possibilities. Incremental price increases will allow industry to convert heavy oils, biofuels, and gas-to-liquid products to extend the hydrocarbon dominance.
“If we choose to do it, we can double vehicle efficiency with technologies like homogeneous charged compression ignition and diesel. Fifty percent of new cars in Europe are diesel,” he said. “If you include enhanced oil recovery, super deep reserves, tar sands, and oil shale you can extend the petroleum use curve….It depends on what you call oil.”
On the subject of petroleum’s high energy density, Koonin told the audience, “An amazing number for me is that with your average fill-up of gasoline, you’re wielding about 15 megawatts of power. That’s a tremendous number, carrying that kind of power in a small space.”
Koonin focused much of his talk on the environmental consequences of his predictions for the future energy mix. While local pollution “is a solvable problem,” his view of global warming was less positive. There’s a growing body of anecdotal and scientific evidence that “it’s getting warmer,” he said. “There’s a plausible connection of increases of CO2 with these temperature increases.” Although there are complicating factors, there is a strengthening scientific case, he said. “It’s over 50 percent but not 90 percent right now.”
Tough problem to fix
“My own bottom line, and BP’s as well, is that it is extraordinarily unwise to be putting this much CO2 into the atmosphere and that the world should do something about it.” Limited absorption rates for CO2 in the environment, the fact that global warming is less visible than other hazards, and the mismatch of CO2 scales between human activity and life-cycle times in the environment all make it a tough problem to fix, Koonin said.
Growing energy demands also mean that, “We would need to halve the current value of emissions to stabilize the CO2 levels because we are doubling energy use over the same time. He suggested a CO2 rate of 550 per million (twice the pre-industrial level) is workable. It would take about 45 years to stabilize the concentration. “CO2 emissions and concentrations are going to rise unless the world does something dramatically different.”
Koonin noted several transport technologies, including hybridization of vehicles, and light-weighting of vehicles, hydrogen, and biofuels as options for the future. But transport is only about 20 percent of emissions, he noted. For stationary energy sources, he suggested that solar, hydrogen, nuclear, and wind offer potential.
For fighting global warming, Koonin said his personal choices would be carbon sequestration efforts and nuclear power. “BP is practicing carbon sequestration at the Salah gas field in southern Algeria,” he said. Engineers are re-injecting CO2 into the ground and monitoring to see what happens to it, where it will migrate, and “will it stay down there?” He estimates costs may be 30-40 percent higher than venting CO2 to the atmosphere.
Nuclear energy growth will be fixed and probably growing fractionally, he said. “Nuclear and carbon sequestration are necessary to stabilize the climate. For CO2 there are two technologies necessary to have a meaningful impact on emissions: Nuclear and carbon sequestration. Without those two I don’t think the world has a prayer.”
Here are some selected observations from Steve Koonin’s lecture: