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Hierarchical Graphene‐Scaffolded Silicon/Graphite Composites as High Performance Anodes for Lithium‐Ion Batteries
Small ( IF 13.0 ) Pub Date : 2018-10-16 , DOI: 10.1002/smll.201802457
Shanshan Zhu 1 , Jianbin Zhou 1 , Yong Guan 2 , Wenlong Cai 1 , Yingyue Zhao 1 , Yuanchao Zhu 1 , Linqin Zhu 1 , Yongchun Zhu 1 , Yitai Qian 1
Affiliation  

To better couple with commercial cathodes, such as LiCoO2 and LiFePO4, graphite‐based composites containing a small proportion of silicon are recognized as promising anodes for practical application in lithium‐ion batteries (LIBs). However, the prepared Si/C composite still suffers from either rapid capacity fading or the high cost up to now. Here, the facile preparation of hierarchical graphene‐scaffolded silicon/graphite composite is reported. In this designed 3D structure, Si nanoparticles are homogeneously dispersed on commercial graphites and then uniformly encapsulated in the hierarchical graphene scaffold. This hierarchical structure is also well characterized by the synchrotron X‐ray computed nanotomography technique. When evaluated as anodes for LIBs, the hierarchical composite, with the Si weight ratio of 5 wt%, exhibits a reversible capacity of 559 mA h g−1 at 75 mA g−1, suggesting an unprecedented utilization of Si up to 95%. Even at 372 mA g−1, the composite can still maintain a high capacity retention of 90% after 100 cycles. Coupled with the LiFePO4 cathode, the full cell shows the high capacity of 114 mA h g−1 at 170 mA g−1. The excellent Li‐storage properties can be ascribed to the unique designed hierarchical structure.

中文翻译:

层状石墨烯脚手架硅/石墨复合材料作为锂离子电池的高性能阳极

为了更好地与商用阴极(例如LiCoO 2和LiFePO 4)耦合,含有少量硅的石墨基复合材料被公认为是锂离子电池(LIB)实际应用中有希望的阳极。然而,到目前为止,所制备的Si / C复合材料仍然遭受快速容量衰减或高成本的困扰。此处报道了易于制备的分层石墨烯骨架硅/石墨复合材料。在这种设计的3D结构中,Si纳米颗粒均匀地分散在商用石墨上,然后均匀地封装在分层的石墨烯支架中。同步加速器X射线计算机纳米断层扫描技术也很好地表征了这种分层结构。当评估为LIB的阳极时,Si重量比为5 wt%的分层复合材料的可逆容量为559 mA hg -1在75 mA g -1时,表明Si的利用率达到了史无前例的高达95%。即使在372 mA g -1下,复合材料在100次循环后仍可保持90%的高容量保持率。与LiFePO 4阴极耦合后,整个电池在170 mA g -1时显示出114 mA hg -1的高容量。出色的锂存储特性可归因于独特的设计层次结构。
更新日期:2018-10-16
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