Current lithium-ion recycling methods, such as hydrometallurgical and pyrometallurgical processes, only enable the recovery of specific metals, and in a form that is of low-value to battery manufactures. To make lithium-ion recycling profitable, without the charging of large service fees, and to encourage its growth as an industry, methods of direct recycling need to be developed.

Direct recycling enables recovery of cathodes and other materials from spent lithium-ion cells in a condition suitable for direct re-entry into the lithium-ion battery market, providing a lower-cost re-constituted alternative for battery manufactures. Direct recycling is modeled after the approach used by the lead-acid battery recycling industry. However, with lithium-ion chemistries there are several technical issues associated with direct recycling that must be overcome. This is because of the large variety of materials used in lithium-ion batteries and the on-going development of new battery chemistries.

The collaboration will focus on four key challenges that have impeded the adoption of direct cathode recycling for lithium-ion batteries:

  • Cathode Relithiation: Analyze relithiation in the powder and electrode forms. Investigate various techniques to separate cathode types that get mixed together. Develop a new electrochemical relithiation process for restoring the lithium content of the end-of-life lithium-deficient cathode materials. A scalable roll-to-roll format will be designed and developed for direct relithiating.
  • Binder Removal: Determine the best method to remove the binder from cathode particles with minimal damage to the particles’ performance so that costly after-treatment processes are not required.
  • Electrode Relithiation: Develop an energy-efficient recycling process to directly regenerate various degraded cathode active particles (LCO, LMO, NCM, NCA and their mixtures) to revive their high electrochemical performance.
  • Compositional Change: Many of the cathode materials under consideration for recycling may be older cell chemistries that have limited or no market value. The team will analyze the potential to upgrade older compositions to new cathode compositions for use in new batteries. Processes will be developed for converting those obsolete compositions that are determined useable.

Roll-to-Roll Electrochemical Bath Relithiation

Roll-to-Roll Electrochemical Bath Relithiation

The scalable Roll-to-Roll format will be designed and developed for direct relithiating end-of-life cathode materials.
(Courtesy of NREL)