BASF has started R&D activities in the field of lithium-ion battery cathode active materials over a decade ago and has large scale production sites for cathode materials in the US and Japan. Two additional large scale production facilities in Europe are currently under construction in Harjavalta, Finland and Schwarzheide, Germany.
Production of Li-ion battery cathode materials requires a significant amount of nickel and cobalt, as well as a considerable amount of lithium carbonate or lithium hydroxide. Given limited resources especially regarding ethically mined cobalt, and due to the environmental impact of mining operations in general, BASF is highly interested in recycling of Li-ion batteries as a supplemental raw material source to reduce the amount of freshly mined metals required for cathode materials production. In particular, a process that regains the lithium from spent batteries is of importance, as cost of lithium is a significant contributor to cathode material cost. In addition, it is expected that a process that works on spent batteries can also be utilized for recycling of off-spec cathode material or waste from battery cell manufacturing processes at BASF’s customers.
While cathode material manufacturing is the core expertise of BASF’s battery materials R&D activities, BASF has started to look into recycling of cathode active material in in-house R&D projects on laboratory scale early on, using first pristine cathode active material and later on also material derived from spent batteries. However, the previous recycling activities in R&D have been affected by not having access to “real world battery scrap” in significant amount from a scalable industrial process. The close collaboration with Eramet in the ReLieVe project is thus an excellent opportunity for BASF to be part of the development of a recycling route for Li-ion batteries that will enable increased feedstock of key metals for cathode materials production.
In the ReLieVe project, BASF will be working on the processing of the recycled battery grade materials that are prepared by the project partner Eramet, metal sulphates and lithium salts as well as mixed transition metal oxides. The recycled materials will be processed into new cathode active material (CAM) for further use in lithium ion-batteries. Established precipitation and calcination procedures for standard cathode materials from fresh raw material are employed, and if necessary, modified accordingly to accommodate for the feedstock of recycled material. The finished CAM is then be thoroughly analyzed regarding key parameters, like e.g. particle morphology, particle size distribution, lithium to metal ratio and surface composition. CAMs that meet the specifications for a promising battery material will be casted into cathode electrodes and electrochemically characterized in coin-half cells vs. lithium to determine the specific capacity and first cycle efficiency. Long term cycling stability and resistance increase will be evaluated in lab-scale pouch cells against standard graphite anodes. The CAMs derived from the recycled material are benchmarked with conventional CAMs made from fresh raw materials.
In a first step, the processing is carried out with smaller samples in the lab to provide an efficient
and quick feedback loop to the partners, so the processes at the partners can be adjusted if required, e.g. in terms of purity of the material, which is essential for future processing. When the continuously processed feedstock material is available in larger amount, the synthesis of CAM from the recycling feedstock will be upscaled to the kg scale.