Innovation needs for the circular economy of batteries in Finland

Professor Serna

(15.2.21) "Finland remains a country with a comparatively low collection rate for batteries, only around 45%, lower than the average in Europe. This is an evident problem", says professor Rodrigo Serna. He is assistant professor of mineral processing and recycling in Aalto University.

 

A few weeks ago, Finland unveiled its National Battery Strategy, a plan aimed to support the development of the country as a major player in the field of raw materials production for the battery industry. This is a very timely action as the demand for rechargeable batteries is forecasted to increase in the coming years due to ambitious plans on electrification of vehicles and investments on power generation networks. The interest towards electrification is well justified as European countries search for reliable strategies to reach ambitious targets towards carbon neutrality. This unprecedented situation has naturally started discussions on new markets and business opportunities for those countries able to compete in this area. In addition, for those of us involved in the technical fields, this should be considered as a platform for technological innovation. Finland can be considered privileged on the field of battery raw materials, counting with a working mining industry, operating refining facilities, and proven deposits on various of the main components used for battery manufacturing. It is thus interesting that the Battery Strategy is not limited to the production of raw materials from primary sources, but also emphasizes the circular economy of battery materials. In other words, it also addresses activities such as repurposing, remanufacturing and, of course, recycling of batteries.

If carbon neutrality is one of the main drivers of electrification, the extraction of raw materials through recycling can be considered as a suitable complement to it. Indeed, it is well accepted that the reduction of activities associated with the extraction of mineral resources from the earth results in a decreased carbon footprint of raw materials production. How can Finland improve on its recycling activities while positively contributing to the production of raw materials for batteries?

To answer that question, we first need to understand the battery value chains as an ecosystem, involving not only the technological actors (that is, recycling companies and battery manufacturers) but also societal ones, including the general public. It is surprising that, despite its central role in the discussions of battery recycling at the international stage, Finland remains a country with a comparatively low collection rate for batteries. According to statistics form 2018, the collection of end-of-life batteries in Finland was only around 45%, slightly lower than the European average of 48%. This is an evident problem since recycling plants require continuous feed streams at large rates. Why are those missing batteries never reaching the recycling processes, then? The unsurprising answer may be that they remain in our drawers and cupboards. Being an issue rather associated with consumer behavior, this will need to be solved by introducing campaigns of public awareness and by decreasing the existing barriers (technical, geographical, psychological or otherwise) between users and collection points. When a larger proportion of batteries become part of the vehicle fleet as opposed to small portable electronics, a stricter control on the fate of end-of-life batteries may be possible, but adequate standards and policies will nevertheless need to be implemented.

And what about the batteries that do reach the recycling facilities? In such case, one can identify opportunities for technological development as a result of the current limitations in State-of-the-Art (SoA) processes. To discuss such challenges, it is necessary to first understand the composition of lithium-ion batteries (LIBs), the most common type of rechargeable batteries in consumer electronics and electric vehicles. LIBs are complex systems, containing materials in shapes that are difficult to handle, such as micrometer-size particles and thin foils, strongly bound together by polymeric adhesives, activated by flammable and toxic electrolytes, tightly packed in pouches or cylinders, contained in casings of varying shapes that need to be properly discharged before even attempting to being dismantled. If you lost your breath while reading the sentence above, you can imagine how the experts in recycling technologies feel like about LIBs.

Understandably, the SoA recycling technologies have the target of recovering the metals that can be easily accessible or with high economic value. The recovery of casing materials, which include aluminum or steel is performed with an acceptable efficiency already, even though the discharging strategies for safety handling of end-of-life batteries can still be improved. Once casing is removed, batteries are treated mechanically to liberate the active components, resulting in a powder mixture typically referred to as “black mass.” Within the black mass, SoA technologies are interested in the recovery of a single specific metal due to its high economic value: cobalt. Using pyrometallurgical processes, cobalt is currently extracted from the black mass in an efficient manner, but at the expense of losing the rest of the battery materials. This represents losses of components such as graphite, aluminum and copper foils. Innovation is thus necessary to design recycling processes that allow the recovery of a wider variety of materials in a battery. Such an ideal target has driven significant efforts by academics and industry alike, with some emerging processes reportedly recovering most of these valuable components. In our laboratories at Aalto University, we have tested processes for the recovery of lithium, metallic foils and graphite through a careful integration of mechanical separation, hydrometallurgical and pyrometallurgical processes, for example.

Batteries for recycling

 Photo: Severi Ojanen 2017

It is fair to say that the actors involved in the recovery of materials from LIBs have a good understanding of the challenges of SoA technologies, and it is time to take action upon it to support the national roadmaps through high quality science and technological innovation. In the short to mid-term, we should aim at finding recycling technologies to recover a wide range of components. While lithium and graphite have not been of much interest, for example, they are slowly being recognized as valuable components, and even critical under some definitions. These new technologies should also have low environmental impact, perhaps involving chemistries with low toxicity and an optimized energy consumption. The full recovery of valuable raw materials would be truly in line with the principles of the circular economy. In the longer term, innovation should follow a more holistic perspective, ideally producing LIBs offering good performance, longer lifetimes, while at the same time being designed with recyclability in mind. A battery with such characteristics may sound utopic, but revolutions always follow ambitious aims!

 

 

Rodrigo Serna-Guerrero

Assistant Professor, Mineral Processing and Recycling

Department of Chemical and Metallurgical Engineering

Aalto University