Boosting Leaching of Spent Ternary Cathode via Strong Van Der Waals Force Beyond Hydrogen Bonding.

Abstract

Promoting the green and efficient recycling of critical metals in spent ternary batteries represents a crucial step in driving the reduce of resource dependence in the electric vehicle industry. However, the leaching progress of metals from spent cathodes generally requires high reaction temperatures and large usage of solvents. Herein, a strategy is proposed to strengthen the van der Waals forces between solvent components by constructing affinity interactions between functional groups (e.g., -OH and -COOH), which can significantly enhance the leaching kinetics of metals at a high solid-liquid ratio and low temperature (30 °C). The results demonstrate that the strong van der Waals force between ascorbic acid with -OH group and betaine ions with -COOH group can strengthen the nucleophilicity of the carbon atoms and reduce the specific C─C bond energy, thus enhancing the redox capability of the DESs. Encouragingly, the designed solvent shows an impressive leaching performance at a super high S/L ratio (1: 3) without external heating for the actual black mass under a scaled-up experiment.