Oral Presentation International Solvent Extraction Conference 2025

Phosphoric Acid Extraction for a Closed Process for Recycling and Re-Synthesis of Spent LiFePO4 Cathode Material (121557)

Quang-Tuan Bui 1 , Marco Wenzel 1 , Juan Luis Gómez Urbano 2 , Andrea Balduci 2 , Mirco Ruttert 3 , Hao Du 4 , Jan J Weigand 1 5
  1. TU Dresden, Dresden, Germany
  2. Center for Energy and Environmental Chemistry Jena, Friedrich-Schiller-University Jena, Jena, Germany
  3. E-Lyte Innovations GmbH, 48149 Münster, Germany
  4. Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
  5. Department of Chemistry and Polymer Science, Stellenbosch University, Stellenbosch, South Africa

The transition to a sustainable energy supply and the development of a circular economy are garnering significant global attention. Lithium-ion batteries (LIBs) play a crucial role in both areas, serving as essential energy storage systems for mobile and stationary applications,[1] owing to their high cell voltage, energy density, and low memory effect. While commercial recycling processes often focus on LIBs based nickel-manages-cobalt (NMC) cathode materials due to the high value of nickel and cobalt, the recycling of lithium-iron-phosphate (LFP) cathode materials remains in development.[2-4] In this study, we report on a hydrometallurgical processing for the complete reutilisation of the metal ions and excipients obtained from LFP/C cathode powder. Here, H3PO4 was used as a leaching agent, which has the advantage that cross-contamination with other anions can be avoided. While the metal ions Fe(III) and Li(I) were recovered by precipitation as their phosphate salts and successfully used for the re-synthesis of LiFePO4/C, the H3PO4 was recovered by liquid-liquid extraction. The process parameters using cyclohexanol, tributyl phosphate, and Escaid 110 organic phase are discussed. Finally, the suitability of the herein presented approach was validated through the lab-scale electrochemical characterization of the recycled samples.

 

Acknowledgements:

The authors gratefully acknowledge financial support by the Sino-German Collaboration of the German Science foundation (Project No. WE4621/4-1/392417756) and the German Federal Ministry for Economic Affairs and Climate Action (Swell 03ETE042C). The authors also thank ExxonMobil for providing the organic diluents used for the liquid-liquid extraction in this study.

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