Dave Hermance at the 2006 ZEV symposium, Sacramento, CA

Dave Hermance at the 2006 ZEV symposium, Sacramento, CA

The question is being asked quietly in small circles. Niche markets have already started putting Lithium Ion (LI-ION) batteries in cars to make them plug-in electric cars. At the same time, lithium-ion batteries are being recalled from laptops. If the small lithium ion batteries are having problems, will the larger, more powerful lithium-ion batteries have the same problems in hybrids and fuel cells vehicles that have LI-ION batteries inside them?

There have been rumors and old wives tales about batteries for years. Weve heard that cellphones can cause brain tumors, that putting your laptop on your lap can cause infertility. The one problem that is indisputable is that batteries explode.

Our world has become the immediate gratification kid generation. We conspicuously consume more than we need with very little regard to the rest of the world or the future generations, or our own safety. We use so much energy that we forget that there are inherent dangers in those energies. Whether we use electric energy or gasoline to fuel our vehicles there is a risk of volatility. The same for batteries. When batteries are made they are made with chemical compounds that have the ability to react adversely, or in laymans terms, they can blow up. Part of the problem could be how much energy and power we are asking from these batteries.

Our growth in technology and the hybrid electric vehicle (HEV) market are integrated with the energy storage systems we are able to create. We want smaller laptops and smaller cellphones, but we want them to do more than ever before. We take for granted that the technology used in these devices are safe, but there are limitations with these batteries that need to be understood, starting at what is energy and what is power and what is the difference between a lithium-ion laptop battery and a lithium-ion car battery?

According to Dave Hermance, Executive Engineer for Advanced Technology Vehicles, Toyota Motor Co., “Power (for electricity) is current times voltage usually expressed in Watts or kilowatts (W or kW). Energy is power times time, usually expressed

as kilowatt hours (kW-h). An analogy would be that energy is like money in the bank, more is good, but it is always limited. On your utility bill you pay for total energy used usually in unit’s of kilowatt hours. A high energy battery stores more energy per unit weight, says Hermance, but usually delivers less peak power per unit weight. If you only have the battery to power your device (cell phone or computer) you want a high energy battery so that it works longer. Peak power is not critical as power demand is fairly small.””Power is the rate at which you spend the money. Higher power equals shorter shopping sprees. Power is the rate at which you are using energy, one light bulb might be 100 Watts if you burn it for 10 hours you use 100 times 10 hours or 1,000 Watt hours which is 1 kW-h of energy. If you run a vacuum, you might use 1,000 W for 1 hour, which is also 1 kW-h. A high power battery delivers a higher burst of power, but stores less energy. If you have a hybrid car, you have gasoline for your energy storage, but you want that burst of power.” All hybrids currently produced employ an internal combustion engine, a generator and a Nickel Metal Hydride (NiMH) battery. NiMH is generally realized as an interim battery technology, soon to be eclipsed by the Lithium Ion battery.

Dr. Menahem Anderman founded Total Battery Consulting in 1996 and Advanced Automotive Batteries (AAB) in 2000. Dr.Anderman sit’s on the California Battery Advisory Panel and will conduct the 7th Annual International Advanced Automotive Battery Conference (AABC), May 14-18, 2007. Dr. Anderman is concerned “that there is an increase in pressure to reduce the price of batteries, so much so that it is increasing the risk of volatility.”

Anderman says that volatility is a risk the industry has known about since 93. The magnitude has accelerated. A normal hybrid battery is never fully charged, so that it can absorb the regenerative braking, so it is considerably less volatile. A full Electric Vehicle has to be fully charged. Lithium-ION can be safe, according to Anderman, for a hybrid, plug-in and, eventually, a full EV, but not on a shoestring budget. Auto manufacturers

need to be conservative in their design and manufacturing and robust in their packaging and engineering.Lithium-ion batteries have a high energy density, sometimes referred to as power to weight ratio. This means that for their size or weight they can store more energy than other rechargeable batteries. Each Lithium-Ion battery that uses different materials has their own set of problems. The cobalt Lithium-Ion battery causes thermal runaway. The Maganese Lithium-Ion battery has a durability problem. The iron phosphate Lithium Ion battery takes care of the thermal runaway problem, but it has a lower power ratio. Valence has developed an iron-phosphate battery that will be used in the upgraded plug-in Prius, which is being installed by clean-tech.com. The upgraded plug-in is not manufacture related and may discredit the Toyota Prius warranty if their system is modified. The full EV, Tesla, uses laptop batteries (not Sonys, says Martin Eberhard, CEO Tesla), 6,831 individually wrapped so that if one battery catches on fire, all the others are safe.

On August 14, 2006, Johnson Controls-Saft Advanced Power Solutions (JCS) was awarded a 24-month contract to develop advanced, lithium-ion (Li-Ion) batteries for hybrid-electric vehicles (HEVs) by the United States Advanced Battery Consortium (USABC). In the project, 50% financed by USABC, engineers and scientists at JCS will enhance lithium-ion battery technology for near-future HEVs.

When Anderman was asked which company he thought had the edge in cell chemistry he thought Toyota, Panasonic and Saft were not dramatically different. The difference is in manufacturing experience. For years now, Toyota has had hybrids on the road, gaining high yield manufacturing experience. Other manufacturers have complained that Toyota has been selling hybrids at a loss. For years now I have been saying that hybrids were not just about getting better gas mileage, but about giving auto manufacturers real world technology experience for future cars. The Toyota Prius is due for a redux in 2008 and, according to insiders other than Hermance, there is a strong possibility for the next Prius to have a Lithium Ion battery instead of a Nickel Metal Hydride.

About the Author:

Lou Ann Hammond is the CEO of Carlist and Driving the Nation. She is the co-host of Real Wheels Washington Post carchat every Friday morning and is the Automotive, energy correspondent for The John Batchelor Show and a Contributor to Automotive Electronics magazine headquartered in Korea. Hammond is a member of the North American Car and Truck of the Year (NACTOY), Women's World Car of the Year (WWCOTY), and the Concept Car of the Year.

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