Monday, July 30, 2007

Power Push

By Bridget Botelho

Advancements in battery technology are emerging to meet demands for long-lasting mobile devices and higher gas mileage through hybrid cars.

"The biggest battery technology trend is in transportation, the electrification of vehicles, as well as portable handheld devices and computers. Vehicle technologies are moving faster," said A123Systems Inc. CEO David Vieau. "You can expect to see about 50 models of hybrids in the next three years from different manufacturers."

Battery technologies can be applied in several ways, and the way a battery is put together varies depending on the application, according to Brian Barnett, vice president of technology for Tiax LLC.

"For example, everyone wants a light mobile phone packed with features, and they want (the battery) to last long," Barnett said. "There has been intense development for the past 12 years in lithium ion development for cell phones. Ten years ago, batteries didn't have half the lasting power of today's batteries. Consumer demand for smaller and lighter portable products have created a clear need for improved batteries."

Cambridge-based Tiax recently licensed out its high-energy, high-performance cathode material for use in portable applications. The Tiax cathode is a lithium-nickel material that achieves 40 percent higher capacity than the existing industry standard cathode material used in lithium-ion batteries.

Tiax has adapted its material for implementation in the hybrid electric vehicle market and has begun marketing licenses to its material for automotive products companies.

In early 2005, the company won a contract from the U.S. Department of Energy to find ways of improving a low-cost cathode material to push hybrid electric vehicles (HEVs) further mainstream. The dominant battery technology used in HEVs is nickel metal-hydride, but Tiax researchers have found that lithium ion based batteries are a preferable option due to their high energy density.

"For HEVs, over the next five years or so we will see the introduction of lithium ion batteries -- more energy, higher power than nickel metal-hydride, improving mileage and lowering the weight of the vehicle. After that, we will begin to see true plug-in vehicles on the market," said Barnett.

A typical hybrid vehicle relies on both an on-board rechargeable energy storage system or electric battery and a fuel engine. With upcoming plug-in hybrids, the battery is larger to support more stored power and can be plugged in when not in use, cutting down on the vehicle's reliance of fuel power.

As of this year, the cost for electricity to power plug-in hybrids during all-electric operation in California has been estimated at less than one-fourth the cost of gasoline, according to the department of mechanical and aeronautical engineering at the University of California Davis.

Plug-ins could operate as a hybrid car with a 6 Kwh to 8 Kwh battery -- compared to the 1 Kwh batteries in typical hybrids like a Toyota Prius -- and sustain an all-electric range of 20 miles, said Barnett.

"There is national interest in this now, just when we are ready to bring this to market. We are developing a battery with high energy without making the battery that much bigger or heavier. We have the key materials to make that possible," said Barnett.

Watertown-based A123Systems has made plenty of news with its battery technologies used in hybrid vehicles, as well.

The developer and producer of automotive class lithium ion batteries announced in May that starting in early 2008, BAE Systems will be offering A123Systems' lithium ion battery technology as part of its HybriDrive propulsion system on the DaimlerChrysler Orion VII hybrid transit bus.

A123Systems is also focusing its energy in plug-in hybrid car batteries.

"A lot of people are enthusiastic about all-electric vehicles, but those are impractical because the battery is just so large. Technologically, we are not there yet. The plug-in hybrid is ideal at this point," said Vieau.

A123Systems is working on a battery pack that hybrid-car owners can attach to their vehicles and go from 40 miles per gallon to 140 miles per gallon. The "battery range extension module" can be removed and charged overnight in an everyday household outlet. The company is demonstrating it now and expects it to be available to consumers sometime next year, starting at a price of approximately $10,000, which should go down over time, he said.

Westborough-based Boston-Power Inc. is focusing its research on battery technologies for mobile devices, and plans to introduce a more environmentally friendly platform for laptop computers this summer, reports CEO Christina Lampe-Onnerud.

The company's Sonata product line is a lithium-ion battery for notebook computers with a longer life than typical laptop batteries. A laptop that is constantly running in portable mode experiences battery fade over a few months. The Boston-Power batteries do not begin fading for at least three years, said Lampe-Onnerud.

"Batteries are becoming more and more important as people become more mobile and reliant on battery technologies to run their devices," said Lampe-Onnerud. "We will come out with innovations for other mobile devices in the future."

Environmental concerns are also driving technology decisions for Boston-Power. Its Sonata line is the first rechargeable lithium-ion battery to attain "Nordic Ecolabel" certification, approved as a green technology in the Scandinavian countries.

Last month, Optodot Corp. of Allston, which makes separator technologies for the lithium-ion battery industry, entered into a partnership with Rogers Corp. of Rogers, Conn., to focus on technology and business development of new membrane film products for battery and energy storage applications. The two companies are working to finalize product development and Rogers will sell the separator products. The alliance between the companies is in response to the rapid growth of energy storage requirements in transportation, military and consumer electronics, according to Optodot.

As battery technology researchers find ways to pack as much power as possible into a small platform, they have to keep safety in mind. Consumers saw the results of faulty batteries in the case of Dell Inc., which voluntary recalled more than 4 million Dell-branded lithium-ion batteries with cells manufactured by Sony Corp. because in some cases, the batteries would overheat and catch fire.

"It is a troubling issue, because these materials have a lot of energy and, if released in an uncontrolled manner, it is not safe. You have to pack in power and do it safely," said Tiax's Barnett. "As in the case of Dell, things like that happen all the time but it isn't publicized. We have done audits on these problems looking at issues to modify them and make them safe, and we continue to do that."

As for the future technologies, there will be continued demand for high power and higher energy, said Barnett. The technologies available today have been in development for years, so the advances of tomorrow are in the works now.

"Battery technologies take time to develop because of the materials and science involved," said Barnett. "We have an idea of what the next-generation materials are, but it takes quite a long time to develop them. There are so many interdependent variables. You want a battery that holds its energy for a long period of time, and it needs to be efficient and safe. There are complex trade-offs to consider, which is why it takes such a long time to develop."

Bridget Botelho is a freelance writer in North Providence, R.I.