1.1 The Development of Batteries in Electric Drive Vehicles
1.1.1 The Goals
Energy and environmental issues have long been challenges facing the world’s automotive industry. In recent years, the grim energy and environmental situation around the world has accelerated the strategic transformation of transportation and energy technology, and thus set off a worldwide upsurge of new energy vehicle development. Under the various scenarios depicted in the technology roadmaps of new energy vehicles, hybrid electric vehicles (HEV), battery electric vehicles (BEV), and fuel cell vehicles (FCEV) are generally considered as important development directions for future automotive energy power systems, and have become a high strategic priority of major automobile manufacturers worldwide.
The power battery is an important component of an electric vehicle (EV), directly providing its source of energy. In general, the goals for a powertrain system in EVs are: excellent safety, high specific energy, high specific power, good temperature characteristics, long cycle life, low cost, no maintenance, low self-discharge, good consistency, no environmental pollution, good recoverability, and recyclability. In BEV, the specific energy determines the total driving distance in the pure electric drive mode; the specific power determines the vehicle dynamics, such as the maximum gradeability and the maximum vehicle speed; and the cycle life and the cost of the powertrain system have direct effect ...