Battery innovations boost European EV capabilities
While the deployment of electric vehicles (EVs) is critical to reducing transport-related emissions, consumer concern about battery life continues to limit market penetration. Pressing issues for the EV sector to address include: long-distance travelling; the availability of charging stations; and charging times. “Expanding the range of EVs requires better batteries,” says SUBLIME(opens in new window) project coordinator Jens Ewald from FEV Europe(opens in new window) in Germany. “These however can make vehicles heavier and more costly. Batteries also need to be safe.”
Pioneering new EV battery technology
Solid-state battery (SSB) technology, which could offer much higher energy density than typical lithium ion or lithium polymer batteries, has been identified as one possible solution. As these batteries do not contain flammable liquids, they are also theoretically safer than liquid-based batteries. “The EU could become a key player here, as the technology still needs to be developed,” remarks Ewald. “We cannot compete with current state-of-the-art batteries, because other regions have optimised their processes to produce cheap batteries. We need to pioneer new technology to be competitive.” To achieve this objective, the SUBLIME project brought together a consortium of 16 partners from eight different European countries, covering industry, academia and research. One aim was to reduce the need for rare materials such as cobalt. Sulfur, which is available in greater abundance, was used as a key component for the solid electrolyte. “We began by building small coin cells, like the batteries you have in your remote control or car key,” explains Ewald. “These were tested and then scaled up towards battery cells you might find in an EV – these look more like bricks.”
Ensuring safety and recyclability of cells
SUBLIME demonstrated the feasibility of producing these SSBs at the commercial scale. The project team was also able to demonstrate high levels of recyclability, with around 90 % of material recoverable at the end of product lifetime. Another important result was safety. The team ran a number of tests, heating the batteries to very high temperatures. These trials demonstrated low levels of flammability, a critical element in eventual acceptance of this technology. “Next steps include further optimising component materials, manufacturing SSBs on a larger scale and finally, testing in real-life applications,” notes Ewald. Other aspects that still need to be addressed include improving supply chain stability and further optimising the technology. A challenge in the project was avoiding dendrite formation, which can short-cut the batteries. “We have found ways to mitigate dendrite formation, but more tests are needed,” adds Ewald.
A viable European SSB manufacturing industry
In practical terms, the integration of sulphide-based all-solid-state batteries has the potential to cost-effectively and safely increase the driving range of EVs. “We showed that this battery technology is inherently safe,” says Ewald. “Furthermore, removing the need for cobalt reduces issues of scarcity of critical component materials, as sulphide is available in abundance.” The aim now is to continue moving towards eventual commercialisation and the establishment of a viable European SSB manufacturing industry. “SUBLIME enabled European research institutions and industries to work together on this,” adds Ewald. “This would not have been possible without this project.” This is a critical time to be investing in this technology. Other regions are working to scale up their capabilities in this field and looking to establish manufacturing plants of their own. “We are in a position where we can be competitive,” notes Ewald.