Failure mechanism of Au@Co9S8 yolk-shell anode in Li-ion batteries unveiled by in-situ transmission electron microscopy

Han, Shaobo1,2; Zhu, Yuanmin2; Cai, Chao1,2; Zhu, Jiakun3; Han, Wenbin3; Chen, Lang2; Zu, Xiaotao1,4,5; Yang, Hui3; Gu, Meng2

2019-03-18

10.1063/1.5089660

APPLIED PHYSICS LETTERS   影响因子和分区

0003-6951

1077-3118

Co9S8 has been regarded as a desirable anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity. However, lithium (Li) insertion caused large volume expansion, and subsequent pulverization and capacity decay are the major challenges for its practical applications in commercial LIBs. In this work, we design an Au@Co9S8 yolk-shell nanoparticle (NP) anode and use in-situ transmission electron microscopy to study the structural, morphological, and chemical evolutions in the NPs during lithiation. Our experimental results reveal that Li insertion leads to the volume expansion of the lithiated Co9S8 shell dominantly in the outward direction, and the conversion reaction between Li and Co9S8 induces the formation of a two-phase shell with metallic Co clusters dispersed in the as-formed Li2S matrix. With corroboration of chemo-mechanical simulations, we elucidate that the lithiation-generated comparative softer phase together with the inner stiffer unlithiated Co9S8 phase contributes to the outward only deformation pattern. In addition, the insulating nature of the as-formed Li2S results in an unexpected non-reactive Au yolk during lithiation. Our findings elucidate the significance of considering the dynamical phase transformations of active materials (i.e., Co9S8) for LIBs and provide valuable insights into the rational design of new generation high-performance LIBs. Published under license by AIP Publishing.

SCI ; EI

英语

NI期刊

通讯

NSAF Joint Foundation of China[U1830204]

Physics

Physics, Applied

WOS:000462086600038

AMER INST PHYSICS

20191306687307

Anodes ; Expansion ; Failure (mechanical) ; High resolution transmission electron microscopy ; In situ processing ; Lithium compounds ; Shells (structures)

Structural Members and Shapes:408.2 ; Electron Tubes:714.1 ; Optical Devices and Systems:741.3 ; Materials Science:951

PHYSICS

Web of Science

1.Univ Elect Sci & Technol China, Sch Phys, Chengdu 610054, Sichuan, Peoples R China
2.Southern Univ Sci & Technol, Shenzhen 518055, Peoples R China
3.Huazhong Univ Sci & Technol, Dept Mech, Wuhan 430074, Hubei, Peoples R China
4.Univ Elect Sci & Technol China, Sch Phys Elect, Chengdu 610054, Sichuan, Peoples R China
5.Univ Elect Sci & Technol China, Inst Fundamental & Frontier Sci, Chengdu 610054, Sichuan, Peoples R China

Han, Shaobo,Zhu, Yuanmin,Cai, Chao,et al. Failure mechanism of Au@Co9S8 yolk-shell anode in Li-ion batteries unveiled by in-situ transmission electron microscopy[J]. APPLIED PHYSICS LETTERS,2019,114(11).

Han, Shaobo.,Zhu, Yuanmin.,Cai, Chao.,Zhu, Jiakun.,Han, Wenbin.,...&Gu, Meng.(2019).Failure mechanism of Au@Co9S8 yolk-shell anode in Li-ion batteries unveiled by in-situ transmission electron microscopy.APPLIED PHYSICS LETTERS,114(11).

Han, Shaobo,et al."Failure mechanism of Au@Co9S8 yolk-shell anode in Li-ion batteries unveiled by in-situ transmission electron microscopy".APPLIED PHYSICS LETTERS 114.11(2019).