A Pseudo-electrochemical Intercalation/Deintercalation Method with the Li2TiO3/H2TiO3 Electrode Pair for Lithium Extraction from Brines

Abstract Adsorption is regarded as a green direct lithium extraction process. However, its practical application is limited by the serious dissolution and difficult recovery of adsorbents, as well as a heavy reliance on an external pH environment. To overcome the limitations, this study develops a novel pseudo-electrochemical intercalation/deintercalation method by constructing a Li2TiO3/H2TiO3 electrode pair for lithium extraction. This method is based on water electrolysis with an applied electric field, which in situ establishes a self-supplying acid/base microenvironment within the electrolytic cell. It enables synchronous and efficient lithium release and capture without external chemical reagents. The adsorbent electrode demonstrates excellent cycling stability, retaining over 95.8% capacity after 10 consecutive cycles, with minimal titanium dissolution (average 0.1%). Furthermore, it achieves a lithium adsorption capacity of 39.75 mg·g–1 with outstanding ion selectivity (Li+/Na+ separation factor of 507.66) in simulated Zabuye salt lake brine. This work provides an efficient, stable, and chemical-free strategy for selective lithium recovery, offering a promising route toward sustainable lithium extraction from salt lake resources.