Titanium-based lithium-ion sieves granulated with biomaterial for sustainable lithium recovery

Abstract

• Granulated CS/Am-HTO LISs prepared using amorphous titanium oxide and chitosan. • The beads adsorb Li + efficiently, achieving equilibrium in 8 h with 43 mg/g uptake. • Adsorption follows pseudo-second-order kinetics and Freundlich isotherm models. • Stable adsorption observed even after 6 regeneration cycles in acidic conditions. Lithium is a critical resource widely used in batteries, electronics, and industrial applications due to its energy storage capabilities. Ion-sieving adsorption, utilizing manganese- and titanium-based lithium ion sieves (LISs), is a common recovery method offering high recovery efficiency and ease of operation. However, manganese-based LISs are not stable in acidic conditions, leading to dissolution during the regeneration. Additionally, conventional powdery LISs are difficult to regenerate and recycle, resulting in significant waste and secondary pollution. Herein, this research aims to synthesize granulated chitosan/titanium-based LISs (CS/Am-HTO) with improved stability and faster lithium uptake rates using amorphous titanium oxide (TiO 2 ) as the precursor. The CS/Am-HTO demonstrate high adsorption efficiency, achieving equilibrium within 8 h with a Li + uptake of 43.20 mg/g. The adsorption behavior aligns well with pseudo-second-order kinetic and Freundlich isotherm models. Notably, the beads demonstrated stable adsorption performance and physicochemical durability, with a Ti 4+ dissolution rate as low as 2.8% even after six regeneration cycles under acidic conditions. The findings of this project are expected to inspire further development of LIS granulation using alternative binders to enhance adsorption performance and support continuous lithium extraction process.