Co-operation of hydrogen bonds and dynamic covalent bonds enables an energy-dissipative crosslinked binder for silicon-based anodes

Although silicon (Si) possesses a desirable super-high theoretical capacity, a serious capacity decline caused by the inevitable volume expansion of Si hinders its practical application. To maintain the structural stability of the Si anode and alleviate the adverse effect of volume expansion, herein...

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Bibliographic Details
Published in:Green chemistry : an international journal and green chemistry resource : GC 2024-02, Vol.26 (4), p.278-286
Main Authors: Lin, Xiangyu, Wen, Yong, Wang, Jie, Wang, Shanshan, Sun, Xingshen, Liu, He, Xu, Xu
Format: Article
Language:English
Subjects:
Anodes
Bonding strength
Chemical bonds
Covalence
Covalent bonds
Crosslinking
Deformation resistance
Dissipation
Hydrogen
Hydrogen bonding
Hydrogen bonds
Silicon
Structural stability
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Summary:Although silicon (Si) possesses a desirable super-high theoretical capacity, a serious capacity decline caused by the inevitable volume expansion of Si hinders its practical application. To maintain the structural stability of the Si anode and alleviate the adverse effect of volume expansion, herein, a cross-linked energy-dissipative binder (TCB) enabled by the cooperation of graded hydrogen bonds and dynamic covalent bonds is proposed. Hydrogen bonds act as sacrificial bonds to be dissociated firstly from the weakest to the strongest ones when undertaking the stress produced by Si volume expansion, imparting the binder energy-dissipation property. Meanwhile, the dynamic covalent bonds build a robust cross-linked network to sustain the strain resistance and maintain the structural stability of the Si anode. Consequently, after 150 cycles at 0.5C, the Si-TCB anode can offer a high capacity of 2053.6 mA h g −1 . Commercial silicon/graphite (Si/C) anodes with the TCB binder present excellent rate performance and can function steadily over 300 cycles at 1C with a restricted capacity of 500 mA h g −1 . Additionally, the Si/C||LiFePO 4 full-cell incorporating the TCB binder exhibits a favorable cyclability of 0.19% capacity loss for each cycle. An energy-dissipative and self-healed binder is achieved by combining multiple H-bonds and covalent bonds. Good electrochemical performances of Si and Si/C anodes are delivered, showing great advancement in the development of Si-based anode binders.
ISSN:1463-9262
1463-9270
DOI:10.1039/d3gc04056a