Pretreatment Methods for Recovering Active Cathode Material from Spent Lithium-Ion Batteries

• Published in: Environments (Basel, Switzerland) Vol. 12; no. 4; p. 119
• Main Authors: Barontini, Federica, Francalanci, Flavio, Stefanelli, Eleonora, Puccini, Monica
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 12.04.2025
• Subjects: Aluminum; Batteries; Carbon black; Carbon dioxide; Cathodes; Efficiency; Electrode materials; Electrolytes; End of life; Energy; Environmental impact; Fluorides; Heat treatment; Lithium; Lithium cells; Lithium-ion batteries; Mathematical optimization; Metal foils; Particle size; Pretreatment; Recovery; Recycled materials; Recycling; Renewable resources; Sodium hydroxide; Solvents; Structural integrity; Waste management; Italy; United States > US
• DOI: 10.3390/environments12040119
• ISSN: 2076-3298

The development of environmentally friendly pretreatment processes for spent lithium-ion batteries (LIBs) is crucial for optimizing direct recycling methods. This study explores alternative approaches for recovering active cathode materials from end-of-life LIBs, focusing on environmentally safer options compared to the usually employed toxic solvent N-methyl-pyrrolidone (NMP), using disassembled batteries as test subjects. Various pretreatment methods, including thermal treatment, selective aluminum foil dissolution with a NaOH solution, and the use of eco-friendly solvents such as triethyl phosphate (TEP), are examined on the cathode sheets. The results show that thermal pretreatment combined with TEP provides the most effective approach, achieving a recovery efficiency of 95% while maintaining the morphology and purity of the recovered materials, making them suitable for direct recycling. These methods are further tested on complete battery cells, simulating industrial-scale operations. The TEP treatment proves particularly promising, ensuring high recovery efficiency and preserving the structural integrity of the materials, with a mean particle diameter of approximately 8 µm. Additionally, when applied to cycled batteries, this pretreatment successfully recovers active materials without contamination. This study provides valuable insights into various pretreatment strategies, contributing to the development of a greener, more efficient direct recycling pretreatment process for spent LIBs.