Two-Dimensional Porous Sandwich-Like C/Si-Graphene-Si/C Nanosheets for Superior Lithium Storage.
Two-Dimensional Porous Sandwich-Like C/Si-Graphene-Si/C Nanosheets for Superior Lithium Storage.
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DOI：
10.1021/acsami.7b11721
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发表时间：
2017-11
影响因子：
9.5
通讯作者：
Weiqi Yao;Jie Chen;L. Zhan;Yanli Wang;Shubin Yang
中科院分区：
文献类型：
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作者：
Weiqi Yao;Jie Chen;L. Zhan;Yanli Wang;Shubin Yang
设计并成功制备了一种新型的二维多孔硅/碳纳米片（C/Si-rGO-Si/C）作为上级储锂的阳极材料，其中多孔硅纳米膜生长在还原氧化石墨烯（rGO）的两侧，然后用碳层包覆（记为C/Si-rGO-Si/C）。C/Si-rGO-Si/C纳米片中微孔和中孔的共存提供了快速的Li+扩散速率，并且多孔Si提供了用于电传输的短路径。同时，包覆碳层不仅可以促进形成稳定的SEI层，而且可以提高纳米Si与rGO耦合的导电性。因此，独特的纳米结构提供了具有高可逆容量的所得C/Si-rGO-Si/C电极（在0.2 A g-1下200次循环后为1187 mA h g-1），出色的循环稳定性（在1 A g-1下1000次循环后为894 mA h g-1）和高倍率性能（在5 A g-1下为694 mA h g-1，在10 A g-1下为447 mA h g-1）。
A novel two-dimensional porous sandwich-like Si/carbon nanosheet is designed and successfully fabricated as an anode for superior lithium storage, where a porous Si nanofilm grows on the two sides of reduced graphene oxide (rGO) and is then coated with a carbon layer (denoted as C/Si-rGO-Si/C). The coexistence of micropores and mesopores in C/Si-rGO-Si/C nanosheets offers a rapid Li+ diffusion rate, and the porous Si provides a short pathway for electric transportation. Meanwhile, the coated carbon layer not only can promote to form a stable SEI layer, but also can improve the electric conductivity of nanoscale Si coupled with rGO. Thus, the unique nanostructures offer the resultant C/Si-rGO-Si/C electrode with high reversible capacity (1187 mA h g-1 after 200 cycles at 0.2 A g-1), excellent cycle stability (894 mA h g-1 after 1000 cycles at 1 A g-1), and high rate capability (694 mA h g-1 at 5 A g-1, 447 mA h g-1 at 10 A g-1).