Coordination Environment Engineering of Titanium Spinel for Enhanced Lithium Recovery
Zhao Bing, Wenfei Wei, Yingjun Qiao, Xinyue Sheng, Jun Xu, Zhiqiang Qian, Baoliang Lv, Zhong Liu
Abstract
Salt lake lithium extraction accounts for 35% of global Li 2 CO 3 production, but current adsorbents are limited by single coordination environments. Here, we engineer the coordination environment of titanium spinel (H 4– x Li x Ti 5 O 12, HTO) by selectively exposing (110) and (111) crystal facets to modulate the tetrahedral and octahedral Li + sites. The (111) facet exhibits high adsorption capacity (41.34 mg/g), while the (110) facet offers rapid kinetics (equilibrium in 10 min). Density functional theory (DFT) calculations, Raman spectroscopy, and 6 / 7 Li solid-state NMR (ssNMR) spectroscopy reveal that tetrahedral sites lower dehydration energy and enhance mobility, while octahedral sites enable deeper diffusion and higher capacity. Coordination modulation thus enables a synergistic improvement in Li + adsorption performance. This work highlights facet engineering as a strategy to enhance ion recovery and guide next-generation adsorbent design.