3D-printed polyamide-H2TiO3 composite for selective lithium adsorption: Insights from experimental and theoretical dynamic simulations studies

Abstract

Global decarbonization has increased the demand for lithium-ion batteries (LIBs), leading to a high demand for lithium a critical raw material in the EU. Efficient lithium recovery, especially from water sources, is essential due to the growing demand need for LIB recycling. Adsorption technology is effective for this purpose, but traditional powder adsorbents present operational challenges. To overcome this, 3D printing allows for the preparation of solid monolith adsorbents with improved mechanical stability and reusability. In this work, a polyamide-lithium titanium oxide composite (PA2200-Li₂TiO₃) was 3D-printed using selective laser sintering technology. The composite was characterized using SEM-EDS, TEM, XRD, Raman spectroscopy, TGA and XPS. The adsorbent exhibited up to 87 % lithium adsorption efficiency at a concentration of 20 mg/L and showed high selectivity for lithium over sodium (Li/Na ≈ 37.4) and potassium (Li/K ≈ 60.5). A mechanism involving Li⁺ ion adsorption and transport through Li₂TiO₃’s structural channels has been proposed, with dynamic simulations suggesting that lithium ions preferentially diffuse through these channels due to their geometric and energetic configuration. Thermodynamic studies confirmed an endothermic adsorption process with enhanced performance at higher temperatures. Regeneration tests demonstrated only a 7 % reduction in adsorption efficiency after three cycles, indicating structural stability and the potential for scalable application in lithium recovery processes.