Reducing the dissolution of Mn from LiMn_(2)O_(4)(LMO)and enhancing the stability of film electrodes are critical and challenging for Li+ions selective extraction via electrochemically switched ion exchange technology...Reducing the dissolution of Mn from LiMn_(2)O_(4)(LMO)and enhancing the stability of film electrodes are critical and challenging for Li+ions selective extraction via electrochemically switched ion exchange technology.In this work,we prepared a nitrogen-doped carbon cladding LMO(C-N@LMO)by polymerization of polypyrrole and high-temperature annealing in the N2 gas to achieve the above purpose.The modified C-N@LMO film electrode exhibited lower Mn dissolution and better cyclic stability than the LMO film electrode.The dissolution ratio of Mn from the C-N@LMO film electrode decreased by 42%compared to the LMO film electrode after 10 cycles.The cladding layer not only acted as a protective layer but also functioned as a conductive shell,accelerating the migration rate of Li+ions.The intercalation equilibrium time of the C-N@LMO film electrode reached within an hour during the extraction of Li+ions,which was 33%less compared to the pure LMO film electrode.Meanwhile,the C-N@LMO film electrode retained evident selectivity toward Li+ions,and the separation factor was 118.38 for Li+toward Mg2+in simulated brine.Therefore,the C-N@LMO film electrode would be a promising candidate for the recovery of Li+ions from salt lakes.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A20303,22078217 and U20A20141).
文摘Reducing the dissolution of Mn from LiMn_(2)O_(4)(LMO)and enhancing the stability of film electrodes are critical and challenging for Li+ions selective extraction via electrochemically switched ion exchange technology.In this work,we prepared a nitrogen-doped carbon cladding LMO(C-N@LMO)by polymerization of polypyrrole and high-temperature annealing in the N2 gas to achieve the above purpose.The modified C-N@LMO film electrode exhibited lower Mn dissolution and better cyclic stability than the LMO film electrode.The dissolution ratio of Mn from the C-N@LMO film electrode decreased by 42%compared to the LMO film electrode after 10 cycles.The cladding layer not only acted as a protective layer but also functioned as a conductive shell,accelerating the migration rate of Li+ions.The intercalation equilibrium time of the C-N@LMO film electrode reached within an hour during the extraction of Li+ions,which was 33%less compared to the pure LMO film electrode.Meanwhile,the C-N@LMO film electrode retained evident selectivity toward Li+ions,and the separation factor was 118.38 for Li+toward Mg2+in simulated brine.Therefore,the C-N@LMO film electrode would be a promising candidate for the recovery of Li+ions from salt lakes.
