Exfoliated V5S8/graphite nanosheet with excellent electrochemical performance for enhanced lithium storage
Exfoliated V5S8/graphite nanosheet with excellent electrochemical performance for enhanced lithium storage
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DOI：
10.1016/j.cej.2017.03.069
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发表时间：
2017-07
影响因子：
15.1
通讯作者：
Xing Ou;Xinghui Liang;F. Zheng;Q. Pan;Jun Zhou;Xunhui Xiong;Chenghao Yang;R. Hu;Meilin Liu
中科院分区：
文献类型：
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作者：
Xing Ou;Xinghui Liang;F. Zheng;Q. Pan;Jun Zhou;Xunhui Xiong;Chenghao Yang;R. Hu;Meilin Liu
纳米结构 V5S8/石墨杂化物 (V5S8/C) 通过固态硫化与液体剥离相结合的简便方法合成。 SEM和TEM结果表明V5S8/C杂化材料由超薄V5S8纳米片和石墨片组成。由于V5S8片材的有效剥离和石墨片的有效掺入，V5S8/C混合材料在锂离子电池中表现出优异的电化学性能。令人惊讶的是，V5S8/C 混合电池在 0.1 A g−1 时提供了 1112 mAh g−1 的高比容量；即使高达 1.0 A g−1，700 次循环后仍可实现 846 mAh g−1 的高容量。此外，原位XRD分析表明V5S8/C的高容量源自Li+嵌入和转化反应的结合。而优异的循环性能和优异的倍率性能归因于V5S8层的减少堆叠和导电石墨材料的外涂层，这可以松弛应变并降低Li+嵌入和脱出的势垒。
Nanostructured V5S8/graphite hybrid (V5S8/C) has been synthesized by a facile method combined solid state sulfuration with liquid exfoliation. The SEM and TEM results reveal that the V5S8/C hybrid is consisted of ultrathin V5S8nanosheet and graphite flake. Due to efficient exfoliation of V5S8sheet and effective incorporation of graphite flake, excellent electrochemical property of V5S8/C hybrid is demonstrated for lithium ion batteries. Surprisingly, V5S8/C hybrid delivers a high specific capacity of 1112 mAh g−1at 0.1 A g−1; even up to 1.0 A g−1, a high capacity of 846 mAh g−1is achieved after 700 cycles. Moreover,in situXRD analysis indicates that the high capacity of V5S8/C is derived from the combined Li+intercalation and conversion reactions. While the excellent cycle performance and superior rate capability are attributed to the reduced stacking of the V5S8layers and overcoating of conductive graphite material, which can relax the strain and lower the barrier for Li+insertion and extraction.