Yan Min, Wang Zhao-Yun, Yu Guo-Wei, Huang Rui, Zhang Cai-Yun, Chang Xiao-Ning, Dong Wen-Da, Liu Xiao-Long, Liu Jian, Mohamed Hemdan S H, Liu Zhi-Tian, Li Yu, Su Bao-Lian
Hubei Key Laboratory of Plasma Chemistry and Advanced Materials, Hubei Engineering Technology Research Center of Optoelectronic and New Energy Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430205, China.
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China.
Small. 2022 Jun;18(25):e2201822. doi: 10.1002/smll.202201822. Epub 2022 May 24.
Strong adsorption and catalysis for lithium polysulfides (LiPSs) are critical toward the electrochemical stability of Li-S batteries. Herein, a hollow sandwiched nanoparticle is put forward to enhance the adsorption-catalysis-conversion dynamic of sulfur species. The outer ultrathin Ni(OH) nanosheets not only confine LiPSs via both physical encapsulation and chemical adsorption, but also promote redox kinetics and accelerate the conversion of sulfur species, which is revealed by experiments and theoretical calculations. Meanwhile, the inner hollow polyaniline soft core provides a strong chemical bonding to LiPSs after vulcanization, which can chemically adsorpt LiPSs, and synergistically confine the shuttle effect. Moreover, the Ni(OH) nanosheets with a large specific area can enhance the wettability of electrolyte, and the flexible hollow sandwiched structure can accommodate the volume expansion, promoting sulfur utilization and structural stability. The obtained cathode exhibits excellent electrochemical performance with an initial discharge capacity of 1173 mAh g and a small capacity decay of 0.08% per cycle even after 500 cycles at 0.2 C, among the best results of Ni(OH) -based materials for Li-S batteries. It is believed that the combination of adsorption-catalysis-conversion will shed a light on the development of cathode materials for stable Li-S batteries.
对多硫化锂（LiPSs）具有强吸附和催化作用对于锂硫电池的电化学稳定性至关重要。在此，提出了一种中空夹心纳米颗粒以增强硫物种的吸附 - 催化 - 转化动力学。外层超薄Ni(OH)纳米片不仅通过物理封装和化学吸附来限制LiPSs，还能促进氧化还原动力学并加速硫物种的转化，这通过实验和理论计算得到了证实。同时，内部中空聚苯胺软核在硫化后与LiPSs形成强化学键，能够化学吸附LiPSs，并协同限制穿梭效应。此外，具有大比表面积的Ni(OH)纳米片可以提高电解质的润湿性，而柔性中空夹心结构可以适应体积膨胀，促进硫的利用和结构稳定性。所制备的正极表现出优异的电化学性能，初始放电容量为1173 mAh g，即使在0.2 C下循环500次后，容量衰减也仅为每循环0.08%，是基于Ni(OH)的锂硫电池正极材料的最佳结果之一。相信吸附 - 催化 - 转化的结合将为稳定锂硫电池正极材料的开发提供启示。
