硒化物
硫黄
化学工程
催化作用
材料科学
双金属片
多硫化物
吸附
锂(药物)
无机化学
化学
硒
电极
物理化学
电解质
有机化学
冶金
医学
工程类
内分泌学
作者
Xiyang Kang,Ziqian Jin,Huaiqi Peng,Zihao Cheng,Lijie Liu,Xin Li,Lixia Xie,Jianmin Zhang,Yutao Dong
标识
DOI:10.1016/j.jcis.2023.01.090
摘要
Lithium-sulfur (Li-S) batteries are currently only in the basic research stage and have not been commercialized, which is mainly affected by the poor conductivity of sulfur/lithium sulfide (S/Li2S), volume expansion effect of sulfur and the shuttle effect of lithium polysulfides (LiPSs). Herein, a three dimensional (3D) carbon nanotubes (CNTs) decorated cubic Co9Se8-x/FeSe2-y (0 < x < 8, 0 < y < 2) composite (Co9Se8-x/FeSe2-y@CNTs) is developed, and used as the functionalized mediator on polypropylene (PP) in Li-S batteries. Benefiting from the good electrical conductivity, large number of Se vacancies and the triple block/adsorption/catalytic effects of Co9Se8-x/FeSe2-y@CNTs, the cell with Co9Se8-x/FeSe2-y@CNTs//PP modified separator delivers a high reversible capacity (1103.5 mA h g-1) at 1C after three cycles activation at 0.5C and remains 446 mA g h-1 after 750 cycles with a 0.08% capacity decay rate each cycle. Moreover, at 0.2C, a high areal capacity of 3.63 mA h cm-2 after 100 cycles with a high sulfur loading of 4.1 mg cm-2 is obtained. The in-situ XRD tests revealing the transition path of α-S8 → Li2S → β-S8 during the first charge-discharge process, then β-S8 → Li2S → β-S8 conversion reaction in the next cycles, and firstly determine the sulfur-selenide active intermediates (Se1.1S6.9) during cycles. The work provides a new insight into the development of bimetallic selenide composites by defect engineering with highly adsorptive and catalytic properties for Li-S batteries.
科研通智能强力驱动
Strongly Powered by AbleSci AI