Synergistic effect from coaxially integrated CNTs@MoS2/MoO2 composite enables fast and stable lithium storage

• 作者: Hui Lu Kai Tian Liangmin Bu Xue Huang Xiangyi Li Yue Zhao Feng Wang Jianming Bai Lijun Gao Jianqing Zhao
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（4）
• 页码范围: 449-458
• 页数: 10页
• 语种: 英文

摘要

Molybdenum oxide/sulfide materials are extensively evaluated as high-capacity anode candidates for lithium ion batteries.However,they suffer from rapid capacity decay and poor kinetics.Herein,we report on synergistic effect from structurally integrated coaxial CNTs@MoS2/MoO2 composite material on lithium storage,in which MoS2/MoO2 nanosheets are conformally decorated on carbon nanotubes(CNTs).In-situ synchrotron X-ray diffraction measurement is performed to elucidate synergistic effect among three MoS2,MoO2 and CNTs components for lithium storage.Reaction mechanism exploration reveals that the MoO2 component undergoes reversible Li+intercalation via forming a stable Li0.98MoO2 phase over a voltage range of 3.0 to 0.01 V vs.Li+/Li,without experiencing the conversion reac-tion into metallic Mo,which contributes to long-term stability during charge/discharge cycles.Meanwhile,lithium storage of MoS2 is through lithium and sulfur reversible reaction after the initial con-version reaction of lithiated MoS2 forming Li2S and Mo.The CNTs component enhances electronic con-ductivity and structural stability by minimizing volume change and reaction strains in the CNTs@MoS2/MoO2 composite anode.A desired 68.2％capacity retention upon 2000 cycles at 10 A/g has been demonstrated for the CNTs@MoS2/MoO2 anode,revealing prominent reaction kinetics and structural stability for fast and stable lithium storage,superior to various Mo-based anode materials pre-viously reported.The findings from this study,with the unique insight into the role of structural integrity in combining MoS2/MoO2 materials with the CNTs substrate,offers a strategy for designing composite anode materials for superior lithium storage performance.