In-situ embedding of Li/Al-LDH on epoxy sponge surface during pore-formation for efficient lithium recovery

LDH was in-situ embedded at the sponge skeleton surface. • Embedding LDH at a proper content resulted in smaller pore size, larger porosity, narrow pore size distribution. • The adsorption capacity of LDH epoxy sponge is as large as 8.10 mg/g. • After 15 times cycle adsorption, Li removal rate maintained as 47.87%. • The LDH embedded epoxy sponge showed excellent mechanical robustness and elasticity. Lithium-aluminum layered double hydroxide (Li-Al LDH) powders are still severely restricted in practical Li adsorption due to the unsatisfactory adsorption capacity, severe active component loss and inferior long-term cycling stability. Herein, we propose a novel Li-Al LDH-epoxy lithium adsorption sponge, which is fabricated via an in-situ embedding strategy, where active LDH components are uniformly anchored onto the skeleton surface of the sponge during the pore-forming process. The as-constructed LDH coating on the sponge skeleton presents an ultrathin filmy morphology with a thickness of only several micrometers, which not only well preserves the intrinsic elasticity of the pristine sponge matrix, but also significantly reinforces its mechanical strength. Meanwhile, the resultant hierarchical porous architecture further contributes to the prominent improvement of lithium adsorption performance. The optimized LDH sponge delivers a large specific surface area of 413.26 m 2 /g, a well-defined hierarchical pore system with dual pore sizes of 150 μm and 13.13 nm, and a high lithium adsorption capacity of 7.85 mg/g. More importantly, the composite sponge can stably withstand 50 compression-strain cycles under a high strain of 60% without obvious structural failure. This sponge-supported LDH composite porous system provides a brand-new design paradigm for developing high-performance adsorbents toward practical lithium extraction applications. Download: Download high-res image (115KB) Download: Download full-size image