Power Electronics

Data Points

Battery Tests Suggest Li-Ion is Tough Enough to Rule Automotive Jungle

Researchers in the Power Sources R&D group at Sandia National Laboratories have been driving nails into batteries, heating them to extreme temperatures, overcharging them and putting them into some of the most adverse conditions possible to see how much abuse they can take before they blow up. And for certain types of Li-ion batteries, the answer is a lot.

The research is part of the U.S. Department of Energy (DOE)-funded FreedomCAR program, which is looking at Li-ion batteries to be part of hybrid electric vehicles and eventually plug-in hybrid electric vehicles (PHEVs).

Current hybrid vehicles run on gasoline and use nickel-metal hydride (NiMH) batteries as the energy-storage device for the electric motor. The intent of the battery portion of the FreedomCAR program is to replace the older-type batteries with safe Li-ion batteries that have six times the energy density of lead-acid batteries and two to three times the energy density of NiMH batteries.

“Lithium-ion batteries, generally found in laptop computers and power tools, have greatly improved over the past few years,” says Peter Roth, lead researcher for Sandia's FreedomCAR battery efforts. “In fact, they have improved so much that we expect to see them in hybrids later this year and possibly even in short-range plug-in hybrids within two years.”

Roth notes that the battery industry has made great strides in manufacturing safe, long-lasting, affordable batteries. Sandia has played a role in assuring that the Li-ion batteries are indeed safe and can operate for long periods of time. One way Sandia researchers have helped determine how safe and long-lasting batteries are is by testing them in adverse situations to determine when and how they can fail or leak their electrolyte.

The Sandia research group obtains batteries and battery materials from research laboratories, such as Argonne National Laboratory, and companies that manufacture and sell batteries. Sandia researchers then study the stability of the materials, their flame-retardant performance, the high-temperature integrity of separators between the cathode and anode, and general thermophysical properties.

“We look at fundamental chemistry, wanting to discover the kinds of gasses they emit when they are heated and explode,” Roth says. “We also build smaller prototype batteries that, once we get the chemistry right, may eventually be built full size to go into vehicles.”

Roth says that some of the newer batteries, like the new lithium/iron-phosphate batteries used in handheld power tools, are extremely resilient and less reactive when subjected to extreme conditions, unlike other types of batteries.

These are the type of batteries the FreedomCAR program is seeking, particularly for PHEVs. A PHEV is a regular hybrid that operates on both gas and battery power, but with an extension cord that allows recharging of the vehicle's batteries from an ac outlet. PHEVs make it essential that batteries be completely safe since they will be recharging in people's garages.

Industry experts predict that PHEVs that can run 10 miles purely on electric energy are two to three years away, while PHEVs that can run 40 miles on all electric are three to four years away.

Li-ion batteries that will go into vehicles will be similar to computer laptop batteries. One main difference is there will be “a lot of them,” Roth says.

The first hybrids using Li-ion batteries are expected on the market later this year. Mercedes-Benz soon will launch the S400 BlueHybrid. After that, it will launch the S300 Bluetec Hybrid, a diesel car that is combined with a Li-ion battery. Also, General Motors plans to introduce a 40-mile PHEV with Li-ion batteries in 2010.

Ford, which is also working with Southern California Edison (SCE; Rosemead, Calif.), is said to be the first automotive manufacturer to partner with the utility industry to facilitate advancing PHEVs. The EPRI-Ford program will build on the ongoing Ford-SCE partnership and help determine regional differences in how the operation of PHEVs will impact the grid.

Partnership Will Assess Impact of Plug-In Hybrids on Grid

The Electric Power Research Institute (EPRI) and Ford Motor Co. have announced a three-year agreement to develop and evaluate technical approaches for integrating plug-in hybrid electric vehicles (PHEVs) into the nation's electrical grid system, a key requirement to facilitate widespread adoption of such vehicles.

EPRI will form a collaborative of utilities in the New York-New Jersey area that will test Ford Escape PHEVs. Subsequent trials will be conducted with customers of the participating utilities.

Ford, which is also working with Southern California Edison (SCE; Rosemead, Calif.), is said to be the first automotive manufacturer to partner with the utility industry to facilitate advancing PHEVs. The EPRI-Ford program will build on the ongoing Ford-SCE partnership and help determine regional differences in how the operation of PHEVs will impact the grid.

“This partnership represents a concerted effort by the transportation and electric sectors to work together in advancing PHEV technology,” said Mark Duvall, EPRI's program manager for Electric Transportation. “This effort should accelerate the pace of PHEV development while enabling the utility industry to prepare for the introduction of these vehicles.”

Ford has designed and is building 20 Escape PHEVs for testing in the Los Angeles area under the Ford-SCE partnership. With this new EPRI-Ford agreement, Ford is able to expand the evaluation and demonstration program to include other utilities.

“PHEVs have great promise, but still face significant obstacles to commercialization, including battery costs and charging strategies,” says Nancy Gioia, director of Sustainable Mobility Technologies at Ford. “ Ultimately, such vehicles must provide real value to consumers.”

EPRI, Ford and SCE's research and analysis on the Ford PHEVs will include data from four primary areas: battery technology, vehicle systems, customer usage and grid infrastructure. The analysis also will explore possible stationary and secondary usages for advanced batteries.

Columnist Discusses Obstacles and Imperatives for Renewable Energy

With gas prices approaching $4 a gallon, why do we still not have affordable renewable energy? That's the question that semiconductor industry veteran Alan Elbanhawy ponders in his latest column on the Power Electronics Technology website. In “Renewable Energy: A Matter of Life and Breath,” Elbanhawy explains why we still lack “realistic, viable and pollution-free alternatives to fossil fuel.”

Elbanhawy comments that despite the encouraging work done so far on renewable energy, there's been “no massive and concentrated investment in research to develop and popularize such alternatives. All achievements toward that end, so far, have been made by organizations and individuals on a very limited scope and budget.”

Nevertheless, Elbanhawy says the technical achievements accomplished so far “should fill us all with great optimism about the possibility of achieving a goal of world consumption that is 100% fueled by renewable energy.” Elbanhawy argues that it's imperative we develop renewable energy sources now to avert the economic crisis that is inevitable when our finite reserves of petroleum begin to run out.

The columnist notes another incentive, commenting that the new jobs created by research and adoption of renewable energy “will more than make up for the jobs lost in the fossil-fuel field.” To read the full column, see www.powerelectronics.com.

Three-Phase Drives UPS Sales to Record Levels in 2007

Based on its latest analysis, IMS Research (www.imsresearch.com) estimates that the global uninterruptible power supplies (UPS) market grew by almost 20% from 2006 to 2007. This growth was driven primarily by large three-phase installations into new and refurbished data centers, as well as into developing segments for UPS systems, such as transport and security, according to the market research firm.

Meanwhile, the single-phase segment of the UPS market showed signs of slowing toward the end of 2007. According to analyst Michael Markides, “Although the three-phase sector continues to push the market to record levels, the concern over the U.S. economy can be seen in the lower power segments, which are governed by small- to medium-sized businesses and their related IT investment. The three-phase market will continue to surge. It is too early to say whether the recent slowdown in the single-phase market will persist.”

As a whole, 2007 was a banner year for UPS suppliers worldwide, with IMS Research estimating the worldwide market to be worth $7.4 billion. The firm notes that APC-MGE was the largest supplier with a market share of more than 30%. Adds Markides, “As we see the financial sector globally suffering from uncertainty, it will be interesting to see if this affects large UPS installations in data centers, the main driver of double-digit growth for the market over the past few years.”

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