There is a great under-utilized potential for raw materials in used mobile phones, laptop computers and electric power tools. Many of the battery materials have been classified as critical raw materials (CRM) by the EU. In addition to the well-known Lithium and Cobalt, Fluorine, Phosphor and Rare Earth Elements (REE) are such critical materials. New recycling processes need to be developed and scaled up for the ecological recycling of these CRMs.
Prof. Farouk Tedjar from Nanyang Technological University (NTU) in Singapore gave the opening keynote talk at the CEB2018 Conference on Circular Economy of Batteries in Gothenburg last month. Prof. Tedjar has several decades of experience in different batteries and their recycling processes. He has been involved in e.g. the foundation of the French battery recycling company Recupyl SAS.
In his lecture, Prof. Tedjar reviewed market forecasts, raw material needs and recycling processes for Li-ion and Nickel-Metal Hydride (NiMH) batteries. There are about 5 billion mobile phones in the world, and they contain about 200.000 Tons of raw materials. In addition, it has been estimated that there are another 120.000 Tons of battery materials in laptops and power tools. These values are of the same order of magnitude as annual production of Li and Co, which are 300.000 and 150.000 Tons, respectively. As the metal content in battery waste is higher than in natural ores, there is an urgent need to collect and recycle end-of-life batteries. The importance is increasing rapidly when more and more batteries are produced for electrification of the transport sector.
According to Prof. Tedjar, at least 25 different metals are used in the various battery technologies today. The criticality of Lithium and Cobalt is well known. Less attention has been paid to Fluorine, which is used in the Li-ion battery electrolytes and electrode binders, as well as to Phosphor, which is used in Lithium Iron Phosphate (LFP) batteries. LFP batteries account for about one third of the Li-ion battery market. They are commonly used in e.g. electric buses in China. Moreover, Rare Earth Elements (REE) like Lanthanum are used in NiMH batteries, and all these REEs are lost in the-state-of-the-art battery recycling processes.
The ecological footprint of different recycling processes can be estimated based on their energy intensity and emissions to the environment. The energy intensity of the state-of-the-art high temperature pyrometallurgical processes is high. Prof. Tedjar presented low temperature processing options based on mechanical and hydrometallurgical treatment of battery waste, where all the valuable electrode materials (anode graphite and cathode metals) can be recovered. The carbon footprint of these processes could be much lower than the current processes in use, and they should be gradually scaled up to industrial use.
Dr. Pertti Kauranen works as a project manager at Aalto University coordinating the Strategic Research Council (SRC) funded CloseLoop project, where recycling of Li-ion and NiMH batteries is studied as a part of Circular Economy of metals. The recycling processes will be further developed in the Business Finland funded BATCircle project, a combined effort by more than 20 Finnish companies, cities and research organizations. Both of these projects are in close cooperation with the Future Batter Ecosystem project.