Triple synergistic effects of bismuth doping in spinel-LiMn2O4: A path to high-performance electrochemical lithium extraction from salt-lake brine

The electrochemical extraction of lithium-ion from salt-lake brine has attracted significant global interest due to the rising requirement for lithium resources. The electrochemical extraction system based on LiMn2O4 has emerged as one of the most promising methods for commercial lithium extraction. However, the dissolution of manganese in LiMn2O4 material, caused by the Jahn-Teller effect, poses a significant obstacle to achieving large lithium extraction capacity and long lifespan simultaneously. In this study, we addressed the issue by incorporating Bi3+ into the material. The resulted LMBO material displays a truncated octahedral morphology, with {100} crystal faces facilitating Li+ diffusion. Additionally, Bi3+-doping inhibits the Jahn-Teller effect and expands the Li+ diffusion pathway, thereby, enhancing the stability and Li+ diffusion rate of LMO. In particular, LMBO-2 material exhibits an excellent lithium ion diffusion rate of 2.03 x 10(-9) cm(2)<middle dot>s(-1), and demonstrates outstanding Li+ release efficiency, which reaches 26.46 mg<middle dot>g(-1) per cycle with an average energy consumption of 2.04 Wh<middle dot>mol(-1) in the 30 mmol & sdot;L-1 simulated salt-lake brine. In simulated Zabuye brine solution, LMBO//Ag system displayed an admirably release capacity of 26.17 mg<middle dot>g(-1) characterized by an ultra-low Li/Na ratio, with Li/Na ratio in recovery solution reaching as high as 0.54. These significant findings advance practical applications of LiMn2O4 in brine lithium extraction processes.