Coordination-Solvation Dual-Regulation Mechanism for Green Recovery of Cathode and Solid Electrolyte in All-Solid-State Sodium-Ion Batteries with Superhigh Selectivity

Abstract

Metals in spent all-solid-state sodium-ion batteries (ASIBs) pose severe environmental pollution, resource depletion, and health risks. However, selective and sustainable recovery of these metals from ASIBs remains highly challenging. Herein, we introduce a coordination-solvation dual-regulation (CSDR) mechanism that enables, for the first time, the recovery of both the cathode and solid electrolyte from ASIBs with exceptional selectivity and high sustainability. Guided by this CSDR mechanism, amino acid–based green solvents are employed with a dual function: abundant functional groups provide coordination sites for target metal ions while facilitating favorable solvation interactions, collectively enabling metal leaching. Mechanistically, the superior Na over Zr selectivity originates from differential binding energetics, Na+ forms stable chelate complexes with amino acid ligands with lower binding free energies, whereas Zr4+, owing to its higher charge density and stronger hydrolysis tendency, exhibits weaker coordination affinity and poorer solvation compatibility, thus remaining preferentially in the solid residue.