L.P.R Moraes, H. Rathnayake
University of North Carolina Greensboro,
United States
Keywords: Lithium-ion battery recycling, Critical minerals recovery, Green chemical synthesis, Black mass, Hydrometallurgical process
Summary:
The rapid growth of lithium-ion battery (LIB) for use in electric vehicles and grid-scale energy storage has intensified demand for critical minerals such as nickel, cobalt, manganese, and lithium. Simultaneously, end-of-life LIBs represent a growing secondary resource for these elements. Developing efficient, environmentally responsible, and scalable recycling technologies is essential to strengthen domestic supply chains and reduce reliance on primary mining. Herein, we introduce a green chemical synthesis approach for the direct recovery and conversion of critical metals from the black mass of spent LIBs into active cathode powders. Unlike conventional pyrometallurgical and strong-acid hydrometallurgical processes, our method operates under moderate temperatures, avoids highly corrosive reagents, and enables tunable metal selectivity through solvent composition and process parameters. Black mass derived from NMC-type LIBs was treated using our proprietary synthesis process to enhance metal coordination and dissolution, followed by direct formulation into cathode powders. To guide industrial-scale development, we applied a statistically designed experimental framework using Design of Experiments (DOE) and Response Surface Methodology (RSM). These tools quantified the influence of key operating variables such as temperature, time, solid loading, water content, and solvent formulation, on metal recovery performance. This data-driven approach accelerates identification of robust operating windows and critical trade-offs among efficiency, energy input, and material output, reducing risk and cost while supporting informed scale-up decisions. Initial results demonstrate recovery and conversion efficiencies exceeding 80% for nickel, cobalt, manganese, and lithium under optimized conditions. Avoiding individual element fractionation via co-precipitation, our process enables simultaneous recovery and conversion of Ni, Co, and Mn as a mixed oxalate precursor suitable for cathode powder production. Beyond leaching performance, this work emphasizes process scalability and integration, transforming battery waste into a domestic source of critical minerals. Our approach aligns with circular economy principles by reintegrating these materials into cathode supply chains. Looking ahead, we aim to develop an AI-driven predictive database for diverse black mass feedstocks, enabling real-time optimization and supporting industrial production needs. Ultimately, this research contributes to diversifying critical mineral supply chains, enhancing resource resilience, and advancing sustainable energy transitions through innovative materials recovery technologies.