The development of battery technology has become one of the most significant technological and ecological challenges of our time. What is topical in battery research at the moment?
The demand for batteries is rising enormously due to emission reduction targets. Simultaneously, mining, which is essential for battery production, is facing strong opposition worldwide.
A complicating factor is Western countries' aspiration to reduce their dependence on Chinese battery production. European battery production is struggling with profitability challenges. Europe must now find its sharpest weapons to stay relevant in the competition.
“At VTT, approximately 100 researchers are working on battery technologies. Their research focuses on, among other things, the electrification of transport, battery manufacturing, recycling and the utilisation of recycled materials, the preparation and impact of legislation as well as the digitalisation and diagnostics of battery manufacturing and use,” says Marja Vilkman, Principal Scientist at VTT.
Battery research aims to develop solutions that extend battery life, increase energy density, improve performance and reliability and reduce carbon dioxide emissions from battery manufacturing. Moreover, batteries should utilise the safest possible, even bio-based raw materials and meet the challenges in mining and recycling.
From Chinese lithium batteries to bio-based, locally produced batteries
Currently, most batteries are lithium-ion batteries. Other battery technologies at various stages of development are sodium-ion batteries, solid electrolyte batteries, lithium-sulfur batteries, metal-air batteries and organic batteries that do not contain any materials acquired through mining. Different battery chemistries have their own advantages.
“For instance, solid electrolyte batteries do not contain flammable solvents, making them safer than lithium-ion batteries in that respect. The advantages of sodium-ion batteries compared to lithium-ion ones are faster charging, better availability of materials and low price,” says Vilkman.
Compared to current batteries, the energy density of solid electrolyte batteries is almost double, and thanks to dry coating, their manufacturing consumes up to 40 percent less energy. On the other hand, scaling their production is challenging. Sodium-based batteries, in turn, can utilise locally produced materials such as lignin, a forest industry by-product. However, their energy density remains lower compared to lithium batteries.
“Further in the future, wood-based batteries are on the horizon. VTT is currently developing various carbon materials from lignin that can replace, for instance, graphite used in batteries. The materials being developed include activated carbon, hard carbon and biographite. At present, we are scaling up material solutions for batteries and are seeking interested partners for technology transfer,” says Research Manager Katariina Torvinen.
Recycling and reuse are progressing, but they do not solve everything
Regulation in the battery sector is tightening. Recycling requirements for critical materials are increasing, and the EU is about to ban the use of fluorinated PFAS materials, known as "forever chemicals." Additionally, a battery passport will be introduced, which would disclose information such as the raw materials used in the battery, their origins and the carbon footprint of the battery.
“There are good solutions available for repurposing batteries. For instance, Volvo collects old batteries and integrates them into energy storage products, where they still function very well. Only after this phase do the batteries end up in recycling,” says VTT Research Professor Mikko Pihlatie.
Recycling can partially meet the demand for battery materials. Research is underway on how to recover metals from old batteries, electronic waste, bottom ash of waste incineration and mining tailings.
However, the demand for batteries will grow so rapidly in the coming years that new metals will inevitably have to be mined. This must be done in an environmentally sustainable and highly efficient manner. Over time, the proportion of materials sourced through recycling is expected to increase.
“The battery value chain is evolving in Finland. With the Keliber lithium project built in Central Ostrobothnia, Finland is set to become the first European producer of battery-grade lithium hydroxide. Finland also has deposits of other critical raw materials – these must be exploited to achieve EU’s mining self-sufficiency target,” says Research Professor Päivi Kinnunen from VTT.
There is no single winning battery technology
The size of battery market is multiplying. Batteries are being developed for heavy-duty transport, the mining industry, loading equipment, forestry machinery, agriculture, maritime shipping, rail transport and energy storage. However, there is a long way to go from material development to practical applications.
“Different applications require different types of batteries. It is not worth equipping every vehicle with an oversized super battery, as critical raw materials are only available in limited quantities. For solar and wind energy storage, in turn, the battery's energy density is not the most essential factor because a much bigger container can fit on the plot," says Vilkman.
Depending on the needs and use case, the emphasis may be, for instance, on low cost, charging speed, cycle life, safety or energy density. Therefore, there will not be one perfect battery chemistry. Battery technology development requires continuous research and piloting.
“Finland possesses exceptionally strong expertise in vital areas for battery development such as thin-film technology, automation, modeling, raw material availability, recycling and manufacturing. Now is the time to harness this expertise effectively," Vilkman says.
VTT is developing new battery technology in, for instance, the following research projects: LITHOS, Nextbat, Escalate, BigLeap, Hidden, SOLiD, Fastest and Batmax.
Read Marja Vilkman's view on the Nordic countries' trump cards in the global battery competition.
