Advanced anodes composed of graphene encapsulated nano-silicon in a carbon nanotube network. Issue 26 (9th March 2017)

• Record Type: Journal Article
• Authors: Ding, Xuli; Wang, Haifeng; Liu, Xiaoxiao; Gao, Zhonghui; Huang, Yangyang; Lv, Danhui; He, Pengfei; Huang, Yunhui
• Is Part Of: RSC advances. Volume 7:Issue 26(2017)
• Page Start: 15694
• Page End: 15701
• Publication Date: 2017-03-09
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra01877k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : In situ growth of hierarchical Gra/CNT was achieved for a Si@Gra@CNT composite, and the composite exhibit improved electrochemical performance as a LIB anode. Abstract : High-capacity silicon-based anode materials with high conductivity to promote electron/ion transfer and excellent elasticity to alleviate volume expansion during repeated lithiation/delithiation process are highly desirable for next-generation lithium-ion batteries. Herein, we developed a facile in situ synthesis method based on chemical vapor deposition to fabricate Si-based nanocomposites integrated with interlinked graphene (Gra) and carbon nanotube (CNT). With melt-assembly nanosized Cu as the catalyst, hierarchical three-dimensional conductive Gra/CNT networks were in situ grown onto Si nanoparticles (SNPs) to achieve the Si@Gra@CNT composite. Such a hierarchical structure combines multiple advantages from SNPs with a super high capacity, Gra/CNT framework with continuous electrical conductivity, and void space for tolerance of Si volume expansion. Moreover, the SNPs were conformally encapsulated by few-layer Gra (fGra), which can protect the SNPs from direct exposure to electrolyte, resulting in a stable solid–electrolyte interface. As an anode material for Li-ion battery, the as-prepared Si@Gra@CNT composite exhibited a high initial specific capacity of 1197 mA h g −1 at a current density 2.0 A g −1 and ∼82% capacity retention over 1200 cycles, which was much better than those of Si@Gra and Si@CNT composites. The mechanism for the improved electrochemical performance was further analysed from the aspect of the synergetic effect arising from the construction components.