When ageing causes a battery to lose a certain amount of its capacity, the battery becomes unusable for efficient electric driving. Since a reduced capacity means that part of the battery pack is inactive, redundant mass has to be moved, resulting in waste energy consumption. For automotive applications the limit for acceptable capacity loss is typically set at 20% (80% capacity remaining). The “battery life time cost” is the cost of the battery when distributed over the life cycle of the vehicle. The “routes”, mentioned above, are improving the life time of the battery and through developing new business models to increase the residual value of the battery at the end of life through second use in renewable applications.
In this sense, these batteries could still be used in applications where the requested performance and parameters - particularly the remaining energy density in Wh/kg - are not as demanding as in EV application. An example is grid-connected applications (i.e. peak-shaving, power quality or renewable integration). For this reason, a reliable estimation of the remaining lifetime is needed for a thorough economic assessment and potential battery cost reduction. Figure 1 shows the schematics of potential increase of battery residual value by adding a second life application.
Battery cost needs to be reduced by at least 50% for electric vehicles to be cost-competitive against conventional vehicles. High purchase price constitutes one of the major inhibitors to the EV market and hence, several complementary approaches towards cost reduction need to be explored in detail. One of the main methods to potentially reduce the total cost of ownership of batteries is to reuse them in second life applications, especially in the field of renewable energy sources, such as photovoltaics, where Europe has a leading position. The analysis of reuse and recycling of batteries is a key issue for the competitive development of electrical energy storage solutions for transport and renewable energy sectors. BATTERIES2020 will make both analyses in depth based on the consortium’s proven expertise in recycling and renewable energy applications.