Sample preparation procedures for elemental analysis of critical raw materials in lithium-ion battery black mass: Challenges responding to the supplementary battery recycling regulation.

Accurate assessment of black mass (BM) composition is critical for implementing the European Commission's proposed methodology for calculating and verifying recycling efficiency and material recovery from waste lithium-ion batteries (LIBs). BM, derived from spent LIBs, presents analytical challenges due to its complex matrix and high-carbon content, which can impede complete dissolution and bias recovery calculations. Incomplete BM digestion and inconsistencies in analytical methods can lead to overestimated recycling efficiencies. This study evaluates and optimizes sample preparation strategies, including digestion protocols and analytical techniques, to reliably extract and quantify critical metals such as lithium, cobalt, nickel, and manganese. To address these issues, we propose standardized digestion procedures and highlight the suitability of techniques like TXRF, which mitigate matrix effects and enhance data reliability. This research underscores the importance of defining clear standards and methodologies in the regulatory framework, ensuring that reported recovery rates accurately reflect true recycling efficiencies. Finally, this work proposes some regulatory and policy improvements, intending to better align with the EU's sustainability goals, promoting reliable data, advancing circular economy objectives, and supporting the broader energy transition.