Crash Safety of Hybrid- And Battery Electric Vehicles

Besides the suitability for daily use, sufficient cruising range, rapid battery charging times and an area-wide service infrastructure, the crash safety performance will also play a key role for the consumer’ s acceptance of electric vehicles. In particular, the electric energy storages and high voltage systems are very challenging to the crash safety performance. Already in the Mercedes-Benz S 400 HYBRID in 2009, worldwide the first series-production vehicle with a Lithium-Ion battery, a seven-stage safety concept has been implemented. It has an extremely high performance in terms of functional and operational safety during normal driving and an outstanding crash performance in any real world accidents. Similarly, an intrinsically safe packaging concept has been implemented in all other Mercedes-Benz Hybrid- and Battery Electric Vehicles, such as the ML 450 HYBRID, the A-Class E-Cell, the B-Class F-Cell, and the Smart Electric Drive. All safety relevant components of the high-voltage system have been integrated and protected in a safe manner. This is particularly true for the high voltage battery. The HV-system has been isolated and protected against any contacts, and it will be shut-off in any accident. In the future Mercedes-Benz hybrid- and electric vehicles, this safety concept will be enhanced consistently, by utilizing the Mercedes-Benz safety philosophy of “Real Life Safety”. Its key elements are: (1) A foolproof strategy to cut-off the high voltage in accidents will prevent any electric shocks; (2) A concept of protection zones defines the accident-proof placement of all the safety relevant high voltage components along with the highest possible structural safety; (3) Mechanical requirements for HV-components ensure the electric insulation and shock-proof protection; and (4) An integrated safety concept shall prevent any critical damages to the high voltage battery in case of high crash loadings. This paper illustrates Daimler’s concept for crash safety of hybrid- and electric vehicles.