Fırat
Tekmanlı

As project manager, under the supervision of my PhD advisor, I led the TU Clausthal (IGMR) work packages within a publicly funded multi-partner consortium and managed the technical execution of thermal pretreatment, flotation, and hydrometallurgical processing — optimizing complex chemical processes such as the synergistic leaching of mixed LFP and NMC black mass and purification routes to recover high-purity battery elements. LiBinfinity was a multi-partner circular economy initiative coordinated by LICULAR GmbH as the consortium leader, alongside industrial partners Mercedes-Benz AG, Daimler Truck AG, Primobius GmbH, and SMS Group, together with the Karlsruhe Institute of Technology (KIT) and TU Berlin. I provided the recycled high-purity materials to project partners so that their performance could be benchmarked against commercially synthesized battery raw materials, and contributed the energy-mass flow data behind the consortium's life cycle assessment of recycling routes capable of reducing CO₂ emissions. I also spent time on-site at the Mercedes-Benz battery recycling plant in Kuppenheim, Germany.

I served as project manager for our institute's work packages within a multi-partner circular economy initiative focused on end-of-life lithium-ion battery recycling, owning the work package operations. My technical focus was hydrometallurgical processing. I led the execution of the chemical leaching and precipitation routes used to recover high-purity battery metals. I subsequently evaluated the recovered materials to determine their competitiveness with commercially synthesized battery raw materials. Additionally, I analyzed, engineered, and compiled the energy-mass flow data behind the Life Cycle Assessment (LCA) modeling, which validated the environmental impacts and sustainability of the developed recycling routes.

This project was my entrance ticket into the colorful world of batteries and hydrometallurgy. I was hired by META Nickel Cobalt Inc. R&D Department mainly for this specific project. It involved enriching mixed hydroxide precipitate (MHP) into battery-grade separated Nickel, Cobalt and Manganese sulfate crystals, followed by cathode active material precursor synthesis using them via the co-precipitation method, followed by slurry and electrode preparation, coin-type half-cell assembly to conduct electrochemical cycle tests, and finally up-scaling of the entire process. Leading a small team of technicians, I conducted batch leaching of the MHP cake, neutralization, and impurity removal via precipitation followed by solid-liquid separation via filter-press. I set up and led a bench-scale solvent extraction line, utilized ion-exchange columns with various resins, and accomplished the crystallization of purified raw materials from raffinates. In the subsequent stage, I synthesized NMC precursor via the co-precipitation method using these recovered raw materials at my university's Energy Storage Laboratory, under the supervision of my Master's advisor. I performed all material characterizations (I was an authorized operator for the department's SEM), electrode slurry preparation, thermal treatments, aluminum foil coating, coin cell assembly in a glove box, and various electrochemical tests (cycle, impedance, etc.). In the project's final stage, it was time to scale up the holistic process. Pilot-scale equipment for both hydrometallurgy and NMC synthesis was manufactured by ASOS Mechatronics Automation, in active collaboration with our project team. Once the pilot system was installed and operational, TÜBİTAK RUTE completed the manufacturing of a 10 Ah lithium-ion pouch cell and validated its performance through 1,000 charge-discharge cycles and safety tests.

In this contract I investigated an acid-free process to achieve selective nickel and cobalt extraction from an industrial partner's intermediate product from battery recycling. I determined a systematic Design of Experiments approach, advancing from initial screening tests to full factorial and Box-Behnken designs for response surface modeling. I aimed to maximize extraction efficiencies by optimizing critical parameters. Subsequently, I developed and validated stage-wise hydroxide precipitation protocols from the Ni & Co bearing solution to obtain high-purity final products.

I served as a shift lead in a pilot-scale solvent extraction campaign evaluating an alternative organic diluent for an industrial partner. The circuit utilized a real leach solution derived from end-of-life NMC battery black mass. During my shifts, I supervised and trained a team of technicians and working students, teaching them the system's mechanics and extraction principles while maintaining strict operational control. My own work focused on monitoring phase separation dynamics and characterizing the organic phase — the part of a solvent extraction circuit that decides whether it runs stably at scale.

As a team of three engineers and three technicians, we commissioned an integrated pilot-scale plant to process mixed-hydroxide-precipitate cake produced by plant process from lateritic ores. The process system was established as a continuous circuit starting from leaching of the cake and feeding the pregnant leach solution into mixer-settler units for sequential separation of Mn, Ni, and Co. Ni and Co bearing solutions were used for electrowinning at the end of the continuous line, resulting in high-purity nickel and cobalt metal sheets which were scraped from the cathode cylinder. We ran the circuit around the clock in three shifts — keeping a full hydrometallurgical line stable in continuous operation is a different discipline from running it for a day. This pilot campaign demonstrated the feasibility of domestic high-purity nickel and cobalt production for demanding applications such as aviation.

Scandium was accumulating in the mid-overflow wastewater stream of the factory. Working with the project team, I took a supporting role in the recovery of Sc. This included laboratory testing to validate the solvent extraction mechanism, specifically focusing on avoiding third-phase formation and tuning organic-to-aqueous (O/A) ratios. When pilot-scale implementation began at META Nickel Cobalt Inc., I had the opportunity to be involved in the commissioning and actively take a role in operating the batch-operated pilot system. Within this circuit, Sc in the wastewater was first concentrated via solvent extraction and subjected to controlled precipitation. The resulting slurry was processed using a tricanter centrifuge for efficient solid-liquid separation, producing high-grade Scandium Hydroxide precipitates.