Self-Healing Core–Shell Interfaces Enabling Adaptive Solid-State Ion Transport Kinetics toward Highly Efficient Seawater Lithium Extraction

Abstract The surging global demand for lithium poses increasing challenges to supply security and sustainability. However, seawater lithium extraction technology with high selectivity and high extraction rate has not yet been developed due to extremely low lithium ion concentration and high competitive ion levels. Here, we proposed an interface engineering strategy to fabricate interface-strengthened core–shell electrodes with interfacial self-healing via 3D coaxial printing for highly efficient seawater lithium extraction. The as-prepared electrode exhibits an outstanding Li+ extraction capacity (35.35 mg g–1) and excellent Li+ extraction rate (3.53 mg g–1 min–1) in a 2200 mg L–1 LiCl solution, together with superior cycling stability (89.2% retention after 200 cycles), high Li+ purity (95.87%), and exceptional selectivity for Li+ (separation factors for Li+/Na+, Li+/K+, Li+/Ca2+, and Li+/Mg2+ of 479.3, 418.1, 135.3, and 81.5, respectively). This interface engineering strategy provides a new avenue for high-selectivity and high-rate lithium extraction from seawater.