Enhancing the desorption/adsorption cycle stability of lithium-aluminum layered double hydroxides type adsorbents for extracting Li+ from sulfate type Salt Lake brines via VO3- intercalation

not-yet-known not-yet-known not-yet-known unknown Owing to its excellent eco-friendliness and facile water elution properties, aluminum-based lithium adsorbents have attracted a surge of interest for selectively extracting Li+ from Salt Lake brines, which account for more than 60% of the global lithium resources. However, structural collapse, facile deactivation during desorption process, and ultra-low actual adsorption capacity limit its further large-scale application, particularly in low-grade sulfate type brines. Herein, taking its advantage, disadvantage and structure features into consideration, the collapse of the aluminum-based lithium adsorbents was obviously suppressed by in-situ intercalation of VO3- ions in to [LiAl2(OH)6]+ layers. Evidently, the initial adsorption capacity and α_Mg^Liof as-configured adsorbents powder are 14.96 mg g-1 and 192.42 in real sulfate type West Taijinar Salt Lake brines following NaCl salts removal with 800 mg L-1 Li⁺ and 9.56 g L-1 SO42-, which are even comparable to those of Mn-based and Ti-based adsorbents. Furthermore, the initial and retained adsorption capacities of this novel adsorbents granulate in brines after 100 adsorption/desorption cycles are 26.68 mg g-1 and 10.36 mg g-1, respectively, which are almost 10 times higher than those of industrially utilized products. Based on the experimental and DFT calculations, the intercalation control process and mechanism were initially elucidated. This work significantly overcomes the major utilization challenges of aluminum-based lithium adsorbents, thereby enabling the high-efficiency and stable extraction of Li+ from low-grade brines, including sulfate type brines.