Innovation Bright sparks
Most people believe that batteries are key to future automotive development. But exactly what kind of battery will do the job is far from clear By John Pullin
I
n the 18months or so since General Motors became the highest profile group in history to go bankrupt, the revived US automaker has become a model of prudent, cautious spending.
So when the group’s venture capital arm shells out $7million to take a stake in a very new Californian start-up company, there’s likely to be a good reason. Envia Systems, the start-up, is a
developer of battery chemistries. And electro-chemistry has become the holy grail for automotive companies worldwide as they search for the big breakthrough that will turn electric vehicles froman expensive and slightly peripheral activity into the mainstreambusiness that will drive future growth. The “game-changing” technology that
they’re all seeking, says Allan Paterson, senior electrochemical engineer with the battery technology group Axeon, is “£2 per charge and 100miles of driving fromit”. At present, he adds, “we’re a little bit away
fromthat but things aremoving so fast and now you’ve got the bigOEMs trying to find the technology, it isn’t very far away.” GM, which is committed to rolling out the Chevrolet Volt – to be called the
High voltage: The Chevrolet Volt, top inset, with President Obama, has seen big spending by GM on power units, top, and test facilities, above
Vauxhall or Opel Ampera in Europe – in large numbers within the next couple of years, is scarcely betting the farmwith its stake in Envia Systems. But it stillmade quite a splash with the news. “Sceptics have suggested it would
probably bemany years before lithium-ion batteries with significantly lower cost and higher capability are available, potentially limiting sales of electric vehicles for the foreseeable future,” said Jon Lauckner, president of GMVentures. “In fact, our announcement today demonstrates that major improvements are already on the horizon.”
The Envia technology is one of a host of
lithium-ion (Li-ion) formulations that are under development in chemistry, battery and auto companies worldwide. It terms it a “high-capacitymanganese-rich” or HCMR electrochemistry, whichmeans it falls into a category of newer Li-ion materials based on lithiummanganese oxide. Paterson at Axeon is working on testing
new formulations in battery cells and complete battery systems. The original Li- ion chemistry used over the past 10 to 15 years in laptop computers andmobile phones had lithiumcobalt oxide as the cathodematerial. Not ideal, he says. “It’s expensive, toxic, the cycle life is not great and there are potential problems with thermal stability, in that you can get a runaway situation where it gets overcharged and can catch fire.” In the small-scale applications where
these batteries havemainly been used, this sounds worse than it actually is, and around 90%of Li-ion battery applications have used lithiumcobalt oxide, withmass production of these cells in the small cylindrical format now a global industry. But the cost and toxicity arguments are
February 2011 ◆ Environmental Engineering ◆ 35
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