Batteries for hybrid systems

The development of high-performance rechargeable batteries for power tools or hybrid vehicles has proved to be an extremely challenging task because of the need to simultaneously meet multiple battery performance requirements, like high energy (watt-hours per unit battery mass or volume), high power (watts per unit battery mass or volume), long life (5-10 years and some hundreds of deep charge-discharge cycles), low cost (measured per unit battery capacity), resistance to abuse and operating temperature extremes, perfect safety and minimal environmental impact. Despite years of intensive worldwide R&D, no battery can meet all of these goals. The use of lithium ion batteries in power tools, vehicles or other applications were high amounts of energy have to be stored in the battery are limited because of safety risks and the lack of safety mechanisms. A wider use of lithium ion batteries for power tools or hybrid vehicles requires safer battery materials and intelligent b attery packaging concepts. The required physical and electrical properties and safety of the lithium ion batteries are supposed to be achieved by the introduction of new materials, e.g. alternative electrode materials and electrolytes. The focussed applications require new designs for the electrode contact deposition, for the heat management and the combination of the single cells into battery modules. In this paper we will focus on the possibilities to improve safety and high temperature performance of lithium ion batteries. The focus will be on nano-scale electrode materials and alternative electrolytes, especially ionic liquids