Adjusting the Chemical Bonding of SnO2@CNT Composite for Enhanced Conversion Reaction Kinetics
Adjusting the Chemical Bonding of SnO2@CNT Composite for Enhanced Conversion Reaction Kinetics
复制标题
调整 SnO2@CNT 复合材料的化学键以增强转化反应动力学
DOI：
10.1002/smll.201700656
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发表时间：
2017-08-18
期刊：
影响因子：
13.3
通讯作者：
Li, Jiayin
中科院分区：
文献类型：
--
作者：
Cheng, Yayi;Huang, Jianfeng;Li, Jiayin
碳纳米管（CNTs）具有优良的电子导电性，被广泛用于提高SnO 2阳极的电化学性能。然而，SnO 2和CNT之间的化学键合并不清楚，尽管它可能会影响锂化/脱锂行为很大。本文报道了一种以Sn-C和Sn-O-C键为连接桥的SnO2@CNT复合材料，并揭示了Sn-C和Sn-O-C键对储锂性能的影响。结果表明，Sn-C键可以作为超快电子转移的途径，促进Sn与Li 2 O之间的可逆转化反应，生成SnO 2.因此，具有更多Sn-C键的SnO2@CNT复合物显示出高的可逆容量，并且接近一半的容量来自转化反应。相反，具有更多Sn-O-C键的SnO2@CNT复合物的电子不能直接转移到CNT，导致转化反应动力学降低。该研究为锂离子电池金属氧化物/碳复合负极材料的开发和设计提供了新的思路。
Carbon nanotubes (CNTs) with excellent electron conductivity are widely used to improve the electrochemical performance of the SnO2 anode. However, the chemical bonding between SnO2 and CNTs is not clearly elucidated despite it may affect the lithiation/delithiation behavior greatly. In this work, an SnO2@CNT composite with Sn-C and Sn-O-C bonds as a linkage bridge is reported and the influence of the Sn-C and Sn-O-C bonds on the lithium storage properties is revealed. It is found that the Sn-C bond can act as an ultrafast electron transfer path, facilitating the reversible conversion reaction between Sn and Li2O to form SnO2. Therefore, the SnO2@CNT composite with more Sn-C bond shows high reversible capacity and nearly half capacity contributes from conversion reaction. It is opposite for the SnO2@CNT composite with more Sn-O-C bond that the electrons cannot be transferred directly to CNTs, resulting in depressed conversion reaction kinetics. Consequently, this work can provide new insight for exploration and design of metal oxide/carbon composite anode materials in lithium-ion battery.