Fırat
Tekmanlı

The LiBinfinity project 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. Primobius and SMS Group were responsible for the mechanical recycling of battery modules into black mass and the baseline hydrometallurgical pilot plant operation. The Karlsruhe Institute of Technology (KIT) managed the resynthesis of cathode active materials and reference cell testing, and TU Berlin handled the Life Cycle Assessment (LCA) modeling. As the project manager under the supervision of my PhD advisor, Professor Bengi Yağmurlu, for the TU Clausthal (IGMR) work packages, I directed an approximate €475,000 budget to handle the next critical phase: further developing the recycling technology. I 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. Finally, I provided recycled high-purity materials to KIT to evaluate if their performance is comparable to commercially synthesized battery raw materials, and provided energy-mass flow data back to TU Berlin, enabling LCA models that validated recycling routes capable of reducing CO₂ emissions. I had the opportunity to be involved on-site, facilitating a mutual exchange of know-how and experience at a TRL7 scale pilot battery recycling factory of Mercedes-Benz being installed in Kuppenheim, Germany.

In this strictly confidential (NDA-protected) project, I served as a project manager for our institute’s work packages within a multi-partner circular economy initiative focused on end-of-life lithium-ion battery recycling. Under the supervision of my PhD advisor, Professor Bengi Yağmurlu, I managed the work package operations and budget over an 18-month period. My technical focus was on the pilot-scale processing of battery black mass. I led the execution of hydrometallurgical processing, optimizing complex chemical leaching and precipitation routes 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 comprehensive energy-mass flow data to support 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 precipitates (MHP ≈ 60% Ni, Co, Mn) into battery-grade (>99.9%) 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 200 kg MHP cake batch leaching, neutralization, and impurity removal via precipitation followed by solid-liquid separation via filter-press. I installed and led a solvent extraction operation line comprising 0.5 L mixer-settler units and utilized ion-exchange columns with various resins, and accomplished the crystallization of purified raw materials from raffinates. In the subsequent stage, I synthesized NMC-622 precursor via the co-precipitation method using these recovered raw materials at my university’s Energy Storage Laboratory, where I had been researching co-precipitation method and cathode material investigations, under the supervision of my Master’s advisor, Professor Kadri Aydınoğlu. 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 my chief, Dr. Şerif Kaya, and me. Once the pilot system was installed and operational, TUBITAK 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. This work resulted in granted patents.

In this contract, under the supervision of Prof. Dr. Bengi Yağmurlu, I investigated an acid-free process to achieve selective nickel and cobalt extraction from a start-up company’s product derived from their battery black mass processing. 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. Followingly, I developed and validated a stage-wise hydroxide precipitation protocols from the Ni&Co bearing solution to get high-purity final products.

In this strictly confidential (NDA-protected) project, I served as a shift lead to evaluate a novel organic diluent developed by a major petroleum company. The pilot-scale solvent extraction circuit utilized a real leach solution derived from end-of-life NMC battery black mass. Over a two-week continuous operation, we conducted sequential, back-to-back trials testing both standard kerosene and the new proprietary chemical in the exact same system to ensure a flawless comparative baseline. During my shifts, I supervised and actively trained my team of technicians and working students, educating them on the system’s mechanics and extraction principles while maintaining strict operational control. By monitoring phase separation dynamics and analyzing the organic phase, the trials successfully validated that the proprietary product achieved comparable Nickel and Cobalt extraction efficiencies, proving it to be a highly effective and stable replacement for standard kerosene diluents.

As a team of three engineers and three technicians, under the supervision of our chief, Dr. Şerif Kaya, we commissioned an integrated pilot-scale plant to process mixed-hydroxide-precipitate cake produced by plant process from lateritic ores. Process system was established with a continuous circuit starting from leaching of cake in 100 L reactors and feeding the PLS into 25 L 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 +99.93% purity nickel and cobalt metal sheets which were scraped from the cathode cylinder. We managed 24/7 continuous operations for three weeks as three shifts eight hours each, producing high-purity metal sheets via pilot-scale electrowinning. This pilot plant validated that the domestic production of highly critical aviation metals for the defense and aviation industries is possible.

Scandium was accumulating in the mid-overflow wastewater stream of the factory. Working under the lead of my chief, Dr. Şerif Kaya, 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.