Continental and Johnson Controls-Saft Teaming on Energy Storage for Mercedes S400 BlueHYBRID
03 March 2008
Continental and Johnson Controls-Saft (JCS) are teaming on the lithium-ion battery pack for the upcoming series-production Mercedes-Benz S400 BlueHYBRID sedan (earlier post), a mild hybrid sedan due to enter production in 2009. As announced earlier, JCS is providing the cells. (Earlier post.) Continental is the pack integrator and will also supply power electronics: the inverter and the DC/DC converter.
For thermal management, Daimler is integrating the lithium-ion battery into the vehicle’s climate control system to ensure that the battery always works at optimal system temperatures of between 15° and 35°C.
The volumetric power density of the entire battery pack is 1,900 watts per liter (W/L), according to Daimler, which declined at this point to discuss further specifications of the pack or the integration and control strategy. Daimler said that the integration of the lithium-ion system was enabled by 25 patents it holds.
As a point of comparison, power density for Saft’s existing VLP line of high power lithium-ion cells (just the cells) ranges from 3,526 W/L for the VL7 P to 2,451 W/L for the VL30 P. In some of the newer, power-optimized cells, such as the VL12 V designed for military hybrid electric vehicles, the power density is 12,000 W/L (18 s pulse).
Combined with the 15 kW hybrid module, the maximum output of the S 400 BlueHYBRID is 220 kW (299 hp), and the corresponding maximum torque is 375 Nm (277 lb-ft). The S 400 BlueHYBRID accelerates from zero to 100 km/h in 7.3 seconds on its way to an electronically limited top speed of 250 km/h (155 mph). The S 400 BlueHYBRID will consume 7.9 l/100km (30 mpg US) in the NEDC, with CO2 emissions of 190 g/km.
The battery cells in this design rely on nickel oxide cathodes and graphite anodes. The lithium comes from the electrolyte, which forms a stable interface (coating) on the anode during the initial charge event.
http://en.wikipedia.org/wiki/Lithium_ion_battery
Saft claims its battery modules (aka packs) are tailored to ensure the performance, thermal and safety requirements of the target application.
http://saftbatteries.com/120-Techno/20-10_Lithium_system.asp
However, there are no specifics on what happens if an automotive battery pack is mechanically or thermally compromised during or after a severe crash. Given that every Li-ion start-up under the sun claims crash safety is the #1 concern for automotive applications, I'd want to see some proof that Saft has licked this problem before getting into an xEV equipped with their cells.
Posted by: | 03 March 2008 at 11:50 AM
I would agree. The A123 and Valence demos show that a regular lithium cell goes bad in a big way when subjected to damage. The more cells, the bigger the event. While I like the BEV, PHEV and HEV ideas with lithium cells, safety is a very big issue.
Posted by: sjc | 03 March 2008 at 12:58 PM
RUN YOUR S400 BLUEHYBRID MERCEDED-BENZ ON WATER
HYDROGEN IS CONDENSED IN WATER AND CAN BE FREED RIGHT UNDER THE HOOD OF YOUR S400 TO FUEL YOUR MOTOR AND HYDROGEN HAS MORE BTU'S THAN GASOLINE. THEY HAVE DRIVEN OVER 100 MILES ON 2 ONCES OF WATER AND EVERY DRINKING FOUNTAIN OR HYDRANT IS A FILLING STATION. WHY SCREW WITH THE OTHER INFERIOR FUELS??? RUN YOUR MERCEDES-BENZ ON WATER!
LEO WELLS
Posted by: LEO WELLS | 03 March 2008 at 05:46 PM
Give it a break Leo, nobody around here is stupid enough to believe a word of it.
Posted by: Neil | 03 March 2008 at 07:10 PM
Leo has been filtered into cyberspace oblivion.
Posted by: sjc | 04 March 2008 at 06:50 PM