So, what exactly are Battaglia and his team focusing their research on? “From a material perspective, lithium metal is a very interesting anode material for next-generation batteries. Compared to today’s lithium-ion batteries with graphite anodes, batteries with lithium-metal anodes can store almost twice the amount of energy per charge,” he says. This would extend the reach of electric vehicles and improve the storage capacity of battery parks. “One major issue for lithium-metal anodes is the tendency to form so-called lithium-metal dendrites, which can provoke a short circuit in the battery. That is where material science comes into play. New solid electrolyte materials are promising to prevent dendrite formation and enable next-generation solid-state batteries.”
Another element keeping researchers around the world on their toes is cobalt. Sixty percent of cobalt is found in the Democratic Republic of Congo (DRC), and the extraction methods have a significant impact on society and the environment. There are alternatives, but their energy density remains a challenge. “Lithium iron phosphate (LFP) for example is cobalt free, but its energy density is lower,” says Battaglia. “We are developing cathode materials based on manganese and titanium, which result in high energy density, but still suffer from relatively low stability when cycled in a battery.”
Empa is also investigating higher-level topics such as a circular economy for batteries. “While manufacturers need to produce millions of batteries as soon as possible, we’re taking a more holistic view and ask ourselves how we can expand the life cycle of batteries and contribute to sustainability,” Battaglia explains. “For example, we are collaborating with the Swiss company Kyburz to develop a novel energy-efficient aqueous recycling route for lithium-ion battery cell assembly.”