Mercedes-Benz bringing first Li-Ion hybrid to market

Despite their position as technology leaders, hybrid cars have spent the last decade in relative torpor. Battery, motor and design technology are all fundamentally the same as they were when the first Prius debuted over a decade ago. Many car makers have been working on new hybrid technologies, but so far very little has actually made it to the market place. Daimler hopes to change that with its new S400 BlueHYBRID, powered by lithium-ion batteries.

Most of us are familiar with lithium-ion technology - we've been carrying it around in our laptops for years. But the perils associated with lithium-ion batteries, from spontaneous flame-ups to excessive heat generation and temperature sensitivity are equally well-known. Those difficulties, in addition to the high cost of the batteries themselves, are what has kept lithium-ion batteries from coming to market in hybrids so far. But Daimler believes it has engineered solutions to all of these problems, and will be introducing the S400 BlueHYBRID in 2009.

The petrol-powered hybrid posts some impressive figures for such a large and luxurious car: 7.9L/100km (29.8mpg US) fuel consumption and 190g/km CO2. And performance is still more than adequate - with 375Nm of torque and 220kW (299hp) on tap, the dash to 100km/h takes a mere 7.3s. Top speed is limited to 155mph.

There are still some limitations on the battery technology, however. It will work optimally only between temperatures of 15 and 35 degrees Centigrade (59 and 95 degrees Fahrenheit) meaning the energy storage capacity of the batteries above and below that range will be compromised. However, when it is working at full capacity, the battery system stores an impress 1.9kW per liter of storage space, and offers excellent longevity, which means fewer expensive battery replacements over the life of the car.

Although other manufacturers are exploring the use of lithium-ion technology, if Mercedes sticks to its release schedule as planned, it will be the first to market in a series-production road car.