(731e) Synthesis and Characterization of Improved Energy Materials from Spent Lithium-Ion Battery Cathodes

Lithium-ion batteries (LiBs) are widely used as electrochemical power sources in energy applications because of their high energy and power density. With the global market for electric vehicles estimated to reach $150 billion by 2025, an efficient and sustainable metal recovery process has become essential to minimize pollution created by disposing of LiBs in landfills. In this work, a closed-loop, sustainable process for recovery of Li and Co from LiCoO₂ (the most common cathode of LiBs) is presented using oxalate chemistry. Oxalic acid has the unique property of separating Li and Co directly by precipitating cobalt oxalate dihydrate (CoC₂O₄·2H₂O) during the digestion while lithium oxalate (Li₂C₂O₄) remains in solution. The addition of hydrogen peroxide as an external reducing agent during the metal extraction process reduces the amount of oxalic acid required for digestion and results in the precipitation of cobalt oxalate dihydrate having a unique micro-rod structure. The rod-like structure is maintained after calcination to form unique cobalt oxide materials (Co₃O₄ and CoO) that can be used in synthesizing high-performance LiCoO₂ cathode materials. This presentation will describe the experimental and mechanistic details of the synthesis and characterization of the improved energy materials along with their applications.