The automotive industry faces major problems in the form of material shortages for semiconductors, challenges in the continued mining of rare earth metals and competition for finite natural resources. These hurdles are particularly relevant for materials used in electric car batteries.
“Electric vehicle batteries play a crucial role in the transition to a sustainable electrified vehicle fleet. Batteries are a major competitive factor, so every car manufacturer is looking for new solutions. Customers are demanding longer range, faster charging, long service life and sustainable technologies that do not deplete natural resources,” says Per Nylén, Professor of Production Technology.
“For University West, it is obvious for us to utilise our expertise to help solve the major climate challenges we are facing. New technologies are needed to allow electrification to be done responsibly. We have recently started two research projects and are planning for more.”
Most electric vehicles today are powered by lithium-ion batteries. In this type of battery, the quality of the welds between the various components is crucial. Lower quality welds can lead to serious problems.
“During fast charging of electric vehicles, the joints in the batteries are exposed to very high stresses. Cracks and other defects in the joints can require repairs and, in a worst case scenario, the battery can start to burn,” says Professor Paul Kah, the head of the Empire research project.
Paul Kah’s research team explores how welds in batteries can be improved so that they have better material properties, greater reliability and improved long-term properties.
“We focus on developing a mix of materials in the joint to provide higher quality. We will also investigate which type of laser welding process offers the best results when manufacturing lithium-ion batteries. With the right joint material and manufacturing method, future lithium-ion batteries can be both safer and longer-lasting.”
Many battery manufacturers are investing heavily in developing solid-state thin film batteries because these can provide faster charging times, higher safety and longer life than current lithium-ion batteries. However, today’s thin-film manufacturing methods to make solid-state battery components are ill-suited for the large-scale deposition of coatings. Deposition rates are typically slow, leading to high costs.
The idea of using thermal spraying when manufacturing components for thin film solid-state batteries is now being tested for the first time. The hope is that it will give the battery components higher performance, better safety and lower manufacturing costs.
According to Professor Shrikant Joshi, head of the NovelCABs research project:
“Thermal spraying is used in a number of different product areas to improve the durability and performance of components – in everything from aircraft engine components to bone implants. It is a cost-effective and versatile technology for giving components robust surface layers. We are now investigating how thermal spraying with liquid feedstock can be used to coat thin solid-state battery components. The techniques we use are suspension plasma spraying and solution precursor plasma spraying. We hope that the project can give Swedish battery manufacturers access to a new robust coating platform for the development of solid-state thin film batteries. This can be a valuable contribution to the next generation of batteries for electric vehicles.”
NovelCABs is a proof-of-concept project conducted in close collaboration between University West and Ångström Advanced Battery Centre at Uppsala University.