Achieving Near-Lossless Adsorption Capacity via Hierarchical All-Fibrous Strategy for Efficient Lithium Extraction

Adsorptive lithium recovery using Li₄Ti₅O₁₂ (LTO) is a pivotal strategy for lithium extraction from salt lakes but faces intrinsic bottlenecks: the agglomeration of LTO particles and the occlusion of active sites arising from the introduction of binders in conventional shaping methods. To overcome these limitations, we propose a novel "hierarchical all-fibrous architecture" strategy to construct a porous composite foam (electrospun LTO cellulose, ELC) by uniformly loading electrospun LTO nanofibers onto the cellulose fiber skeleton. This architecture achieves rapid adsorption kinetics while ensuring robust structural stability. Crucially, this all-fibrous structural design maximises active site exposure. Consequently, the ELC exhibits a superior adsorption capacity of 58 mg/g (approaching the theoretical limit) alongside rapid kinetics (equilibrium within 1.5 h). It demonstrates exceptional structural stability, retaining 90% of its initial capacity after five cycles with minimal titanium loss. In adsorption experiments using simulated brine with a lithium concentration of 210 ppm, its adsorption capacity consistently remained at a high level of 25 mg/g. This work establishes a robust, scalable conceptual framework for high-efficiency lithium extraction, offering a new paradigm for all-fibrous adsorbent design.