Construction of truncated-octahedral LiMn2O4 for battery-like electrochemical lithium recovery from brine

The extraction of lithium from salt lakes or seawater has attracted worldwide attention because of the explosive growth of global demand for lithium products. The LiMn_(2)O_(4)-based electrochemical lithium recovery system is one of the strongest candidates for commercial application due to its high inserted capacity and low energy consumption. However, the surface orientation of LiMn_(2)O_(4)that facilitates Li diffusion happens to be prone to manganese dissolution making it a great challenge to obtain high lithium inserted capacity and long life simultaneously. Herein, we address this problem by designing a truncated octahedral LiMn_(2)O_(4)(Tr-oh LMO) in which the dominant(111) facets minimize Mn dissolution while a small portion of(100) facets facilitate the Li diffusion. Thus, this Tr-oh LMO-based electrochemical lithium recovery system shows excellent Li recovery performance with high inserted capacity(20.25 mg g^(-1)per cycle) in simulated brine. In addition, the dissolution rate of manganese per 30 cycles is only 0.44% and the capacity maintained 85% of the initial after 30 cycles. These promising findings accelerate the practical application of LiMn_(2)O_(4)in electrochemical lithium recovery.

Construction of porous disc-like lithium manganate for rapid and selective electrochemical lithium extraction from brine

In order to satisfy the growing global demand for lithium, selective extraction of lithium from brine has attracted extensive attention. LiMn_(2)O_(4)-based electrochemical lithium recovery system is one of the best choices for commercial applications because of its high selectivity and low energy consumption.However, the low ion diffusion coefficient of lithium manganate limits the further development of electrochemical lithium recovery system. In this work, a novel porous disc-like LiMn_(2)O_(4) was successfully synthesized for the first time via two-step annealing manganese(Ⅱ) precursors. The as-prepared LiMn_(2)O_(4) exhibits porous disc-like morphology, excellent crystallinity, high Li^(+)diffusion coefficient(average 7.6×10^(-9)cm^(2)·s^(-1)), high cycle stability(after 30 uninterrupted extraction and release cycles, the crystal structure hardly changed) and superior rate capacity(93.5% retention from 10-120 mA·g^(-1)). The porous structure and disc-like morphology further promote the contact between lithium ions and electrode materials. Therefore, the assembled electrochemical lithium extraction device with LiMn_(2)O_(4) as positive electrode and silver as negative electrode can realize the rapid and selective extraction of lithium in simulated brine(adsorption capacity of lithium can reach 4.85 mg·g^(-1) in 1 h). The mechanism of disc-like LiMn_(2)O_(4) in electrochemical lithium extraction was proposed based on the analysis of electrochemical characterization and quasi in situ XRD. This novel structure may further promote the practical application of electrochemical lithium extraction from brine.

Progress in electrochemical lithium ion pumping for lithium recovery

Accelerating the development of lithium resources has attracted a great deal of attention with the explosive growth of new energy vehicles.As a new technology,electrochemical lithium ion pumping(ELIP)is featured by environment-friendly,low energy consumption and high efficiency.This review summarizes the research progress in ELIP,and focuses on the evaluation methods,electrode materials and electrochemical systems of ELIP.It can be concluded that ELIP is expected to achieve an industrial application and has a promising prospect.In addition,challenges and perspective of electrochemical lithium extraction are also highlighted.

Electrochemical lithium ions pump for lithium recovery from brine by using a surface stability Al_(2)O_(3)–ZrO_(2 )coated LiMn_(2)O_(4) electrode

The rapid commercialization of lithium–ion batteries has caused significant expansion of the lithium demand.Electrochemical lithium ions pump is a promising technology because of its good selectivity and friendly environment.Herein,an Al_(2)O_(3)–ZrO_(2) film coating of the LiMn_(2)O_(4)(AlZr–LMO) electrode is prepared and operated for recovery of Li^(+)from brine.The Li^(+) maximum extraction capacity of AlZr–LMO reached 49.92 mg/g in one cycle.Compared with the solely LMO electrode,the AlZr–LMO demonstrated evident electrochemical stability and cycle life towards the Li^(+)recovery system.After 30 successive cycles,the extraction capacity for Li^(+)increased from 29.21%to 57.67%.The high cycle capacity of the material could be attributed to its low polarization,high active sites,and good chemical stability of the electrode surface owing to the synergy function of Al_(2)O_(3)–ZrO_(2)in the charging-discharging process.A dynamic model parameter identification method was performed to evaluate the active site of AlZr–LMO.This work may provide a way to design the AlZr–LMO electrode and develop a good method for the recovery of lithium from brine.