Poly(ethyleneimine) modified TiO2 nanorods for adsorptive recovery of lithium from a battery cathode and brine solution

Abstract

Lithium, often referred to as ‘white gold,’ is a vital element in modern technology, and its applications are found in various fields, including Li-ion batteries (LIBs). Being explored for countless technological applications, lithium recovery from spent batteries is a significant concern. In this study, we report a titanium nanorod-based adsorbent modified with PEI for the adsorptive removal of lithium from various sources. The hydrothermally synthesized adsorbent was mesoporous, with a specific surface area of 45.8 m² g⁻¹. The characteristics of the adsorbent material were corroborated using multiple analytical techniques such as BET-N₂ isotherm analysis, XPS, PXRD, TGA, FESEM-EDS, FTIR, and DLS. The maximum adsorption capacity of the material under optimized conditions was 2.76 mg g⁻¹. The adsorption process was endothermic and feasible, fitting well with the Langmuir isotherm following pseudo-first-order kinetics. The spent adsorbent was recovered and exhibited a regeneration capacity of up to 4 cycles. Furthermore, desorbed lithium was successfully converted into Li₂O, contributing to a circular economy.