Li Tengyu, Li Yanan, Yang Jinlin, Deng Yirui, Wu Mengwei, Wang Qi, Liu Ruiping, Ge Ben, Xie Xiaokun, Ma Jianmin
Department of Materials Science and Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, P. R. China.
School of Materials Science and Engineering, Tsinghua University, Beijing, 100083, P. R. China.
Small. 2021 Dec;17(52):e2104613. doi: 10.1002/smll.202104613. Epub 2021 Nov 12.
Li-S batteries (LSBs) have attracted worldwide attention owing to their characteristics of high theoretical energy density and low cost. However, the commercial promotion of LSBs is hindered by the irreversible capacity decay and short cycling life caused by the shuttle effect of lithium-polysulfides (LiPSs). Herein, a hybrid interlayer consisting of MoO , conductive Ni foam, and Super P is prepared to prevent the shuttle effect and catalyze the LiPSs conversion. MoO with a reversible lithiation/delithiation behavior between Li MoO and Li MoO within 1.7-2.8 V versus Li/Li combines the Li insertion and LiPSs immobilization and efficiently improve the LSBs redox kinetics. Benefiting from the reversible Li insertion/extraction in lithium molybdate (Li MoO ) and the highly conductive Ni foam substrate, the sulfur cathode coupled with such electrochemical activation derived catalytic interlayer exhibits a high initial discharge capacity of 1100.1 mAh g at a current density of 1 C with a low decay rate of 0.09% cycle . Good capacity retention can still be obtained even the areal sulfur loading is increased to 13.28 mg cm .
锂硫电池(LSBs)因其具有高理论能量密度和低成本的特点而受到全球关注。然而,锂硫电池的商业推广受到多硫化锂(LiPSs)穿梭效应导致的不可逆容量衰减和短循环寿命的阻碍。在此,制备了一种由MoO、导电泡沫镍和超级P组成的混合中间层,以防止穿梭效应并催化LiPSs的转化。在相对于Li/Li为1.7 - 2.8 V的电位范围内,具有在Li₂MoO₃和Li₂MoO₄之间可逆锂化/脱锂行为的MoO,兼具锂嵌入和LiPSs固定功能,有效改善了锂硫电池的氧化还原动力学。受益于钼酸锂(Li₂MoO₄)中可逆的锂嵌入/脱出以及高导电性的泡沫镍基底,耦合这种电化学活化衍生催化中间层的硫正极在1 C电流密度下展现出1100.1 mAh g的高初始放电容量,循环衰减率低至0.09%/循环。即使面硫负载量增加到13.28 mg/cm²,仍能获得良好的容量保持率。