Strongly cross-linked three-dimensional Li1−xMn2O4/C/SA-c-PEO@GF electrode for lithium recovery from high Mg2+/Li+ ratio salt lake brine

The rapid growth in lithium demand for battery applications has driven the need for safe and efficient extraction technologies from salt lake brines. Current methods face challenges including low recovery rates, slow adsorption kinetics, and environmental concerns from organic solvent usage. To address these limitations, the environmentally friendly electrochemically switched ion exchange (ESIX) system using a three-dimensional LiMn 2 O 4 /C/SA-c-PEO@GF electrode was developed. The electrode employs sodium alginate (SA) and polyethylene oxide (PEO) as chemically cross-linked binders on a graphite felt (GF) current collector. In the constant current-constant voltage coupling drive mode, the system achieved 97% lithium extraction efficiency with an adsorption capacity of 3.89 mg·g −1 and a Li + /Mg 2+ separation coefficient of 191, the energy consumption was 14.51 Wh·mol −1 and 485 mg·L −1 Li + solution was obtained from actual Zarkhan Salt Lake brine (Mg 2+ /Li + : ∼426.6) by one-step concentration. This study shows the LiMn 2 O 4 /C/SA-c-PEO@GF electrode with high extraction efficiency and fast adsorption rate, providing a simple and efficient method for lithium recovery from salt lake brine with high Mg 2+ /Li + ratio.