Current and future developments of batteries for electric cars - an analysis

Abstract

To make battery electric vehicles (BEVs) energetically, environmentally and economically competitive to internal combustion engine vehicles (ICEVs), batteries play an important role. In this study, an overview was created of battery technologies that are now available for BEV application or are currently under consideration in research, development and demonstration (RD&D) activities focusing on battery electric cars. From this inventory, a selection was made of five technologies that can were considered to be most promising in the short (<5 years), medium (5-20 years) and long term (>20 years). The selected technologies were further examined and projections were made on the battery performance and cost in the short, medium and long term. Also, sustainability aspects (raw material availability and the environmental impact of the batteries) were assessed. Finally, driving cycle simulations were carried out to assess how the selected technologies and their development will influence the energetic, environmental and economic performance of battery electric cars. The findings of this study indicate that for all five batteries selected, it remains a challenge to simultaneously achieve all requirements in the medium or even long term. Projections on lifetime, specific power, efficiency and costs are often lower than the USABC requirements and uncertain. Only lithium-ion batteries could possibly attain all conditions in the medium term. Furthermore, while lithium-based batteries have high specific energy potentials, batteries that do not contain lithium have better cost perspectives. Furthermore, the results indicate that battery electric cars will be energetically and environmentally competitive to ICEVs, regardless of the specific battery technology applied. Nevertheless, low efficiencies of metal-air and lithium-sulfur batteries result in higher WTW energy consumption and emissions levels compared to Li-ion and ZEBRA batteries. Finally, recycling of batteries is needed to limit environmental impact as well as to restrict resource depletion and keep material prices low.