Recycling of Lithium-Ion Batteries: Effect of Hydrogen Peroxide on the Leaching of Lco, Nmc Oxides, and Black Mass

Repurposing Kraft black Liquor as Reductant for Enhanced Lithium‐Ion Battery Leaching

“…The leaching yield of Li(I) is significantly better than the remaining metals, especially at lower BL vol% and is not significantly impacted by its presence. A similar behavior was reported in HCl and H 2 SO 4 leaching media [13,41] …”

“…Since Mn(IV) has the highest valency, its leaching is greatly hampered without the introduction of a reducing agent. Similarly, other reports observed low leaching efficiencies for both Mn(IV) and Co(III) in the absence of a reducing agent due to the inability to reduce these high‐valency metals into the readily soluble Mn(II) and Co(II) ions [13,48,49] . The proposed leaching approach exhibits good resilience when applied to various cathode chemistries, achieving near‐complete leaching in most cathode powders.…”

“…Without BL, the leaching efficiency of Mn(IV) ranged from 0.2 to 32.8 %. The digestion of Mn‐rich cathodes is typically more challenging due to their enhanced stability [13,45] . The oxidation states of the metals within each cathode are expected to be primarily Li(I), Ni(II), Co(III) and Mn(IV) [46,47] .…”

“…Counterintuitively, the use of bio‐derived leaching agents based on common organic acids such as formic, lactic, or citric acids yield a larger environmental impact compared to cheaper inorganic acids like H 2 SO 4 due to the carbon footprint and cost associated with their production [12] . However, to facilitate the full dissolution of the more recalcitrant higher valency metal oxides present in the cathode black mass, the latter must be paired with a suitable reducing agent to ensure the reduction of the transition metals present and improve the leaching intensification [13] …”