The major bottleneck for battery driven electric vehicles is the battery. Existing battery types have all their specific draw backs: lead acid batteries give a short range, NaS batteries operate at 300 degrees Celsius and NiCd batteries contain poisonous Cd and are expensive. Li batteries may achieve a range of 200-300 km, operate at room temperature and are expected to be cheap. The EC programme therefore focusses on the development of different concepts for Li batteries. This project aims at the development of Li batteries with gelled electrolytes, based on polymers and organic solvents combined with organic or inorganic agents. The electrolyte should have sufficient stability vs carbon/lithium and high voltage cathodes. The objective is to achieve a conductivity at room temperature which is higer than 10-3 cm-1. New synthetic routes for cathode and anode components, especially lithium manganese spinels and carbon components serving as matrix for Li intercallation, will be investigated.
The project team successfully constructed batteries using the HDS gelled electrolyte that reached the performance targets set at the start of the project in terms of the stability of the electrolyte and the charging capacity. The cathode and anode materials were characterised and gave good performance results. Electrodes based on manganese were also considerably less expensive than comparable electrodes using cobalt or nickel materials.
JOU-401 Brief description of the research project: The development of electrical vehicles demands the use of a high power rapidly rechargeable battery. One of the most promising new technologles which appears feasible in the midterm is rechargeable lithium battery chemistry.
The lifetime of rechargeable lithium batteries is limited by degradation of the electrolyte and the poor cycling characteristics of metallic lithium anodes. Lithium-carbon electrodes offer a good alternative for the anode. The penalties are an increased weight and lower effective voltage. Thus the capacity of the lithium-carbon electrode has to be at its best. Since LiCoO2 is already a well known cathode material, it will be used as a starting and reference point. The intention is, however, to replace this expensive material by suitable and cheaper alternatives and to achieve a degree of intercallation of more than LiC12 in carbon. To meet the requirements of rapid rechargeability and high current drain capability, a gel electrolyte will be used. This suggestion offers a new option for the development of a battery for automobile application, since the problems with liquid or polymeric electrolytes, such as leakage (liquid electrolytes), or interfacial problems and limited cycle number (polymeric electrolytes) can be overcome. The material technology of the components of the battery has to be developed to meet the requirements for its use as an electric vehicle battery, such as high specific peak power density and energy density. Materials will be characterized by electrochemical methods and small-scale cells will be tested.
Funding SchemeCSC - Cost-sharing contracts