Novel method to produce cleaner and safer batteries
A range of safety and environmental issues are associated with lithium-ion batteries, including the potential risk of sudden explosions when used in electric vehicles and the disposal of toxic materials. To address these issues, the European Union (EU)-funded SOMABAT project developed innovative strategies for producing lithium-polymer batteries that are cleaner, safer and better performing than conventional lithium-ion batteries.
The research team demonstrated the feasibility of using recyclable and synthetic materials for the battery components (anodes, cathodes and electrolytes) in the lithium-polymer batteries - advanced type of batteries in which the electrolyte is a solid, polymer composite rather than a liquid.
These novel synthetic and recyclable materials were produced using new synthesis and processing methods that enabled the research team, led by the Spanish Instituto Tecnológico de la Energía, to engineer their various properties.
The project team also investigated new ways of recycling the different components of the battery and performed life cycle analyses. “We conducted a complete analysis, from the raw materials to the final battery, to try to identify the processes that are not environmentally friendly, nor sustainable,” explains SOMABAT project manager Leire Zubizarreta of the Instituto Tecnológico de la Energía in Spain.
SOMABAT researchers developed the first cell prototypes in the first half of the project. “We are finalising the tests with these first prototypes in order to develop, as a second step, improved 2nd generation prototype cells,” says Zubizarreta. The prototype battery cells contain the optimised materials produced during the project, leading to battery cells that have optimal energy density and a long lifetime.
Using the new synthetic and recyclable materials significantly reduces the likelihood of the battery short circuiting, overcharging or over-discharging as well as the impact following critical failures such as crushing the battery. Moreover, potential risks from exposure to fire are lowered as well. Such improvements in safety are particularly relevant to manufacturers of electric vehicles. “Users must feel that they are safe in these vehicles. It is well-known that some explosions could be related to the lithium batteries of electric cars. However, batteries that do not contain free liquids are safer,” explains Zubizarreta.
Cost is also a key issue to greater electric vehicle uptake, and safer batteries are expected to reduce the amount of resources spent on ensuring a vehicle’s safety.
The SOMABAT research team involved experts in the field and experts with complementary R&D expertise across Europe. The European component of the project was integral to its success. “For developing an innovative product such as lithium-polymer batteries you need experts in different areas – materials, batteries integration and simulation, battery management system and recycling. These experts are very difficult to find in one country,” adds Zubizarreta.
In order to facilitate comparisons of the batteries developed and between these and conventional batteries the project team created a model to predict the behaviour of the battery cells. In addition, the recycling companies involved in the project collected data from the materials and battery developers to assess which are the best processes for recycling.
“We have come a long way since the first generation prototypes, and are now working on developing better materials. We detected some parameters in need of improvement, so now we are developing the second generation prototypes. The aim is to achieve a second prototype that takes on these improvements and integrates them in the design of an electric vehicle battery module,” says Zubizarreta.
Industrial involvement was key to the project. The industrial partners are now investigating ways to make the new batteries commercially available. Moreover, several SMEs are working in a range of areas, such as battery management system development, cell integration and recycling.
Last but not least, the project benefitted from a high participation of women in a variety of roles as well as part of the coordination team. “This fact illustrates the encouraging increase in the number of women in a business that is largely dominated by men,” concludes Zubizarreta.