Poly(vinyl alcohol)-Assisted Fabrication of Hollow Carbon Spheres/Reduced Graphene Oxide Nanocomposites for High-Performance Lithium-Ion Battery Anodes.
Poly(vinyl alcohol)-Assisted Fabrication of Hollow Carbon Spheres/Reduced Graphene Oxide Nanocomposites for High-Performance Lithium-Ion Battery Anodes.
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DOI：
10.1021/acsnano.8b01549
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发表时间：
2018-04
期刊：
影响因子：
17.1
通讯作者：
Yunqiang Zhang;Q. Ma;Shulan Wang;Xuan Liu;Li Li-Li
中科院分区：
文献类型：
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作者：
Yunqiang Zhang;Q. Ma;Shulan Wang;Xuan Liu;Li Li-Li
通过一种通用的方法制备了具有高度杂原子掺杂和分级孔结构的三维中空碳球/还原氧化石墨烯（DHCSs/RGO）纳米复合材料。以聚乙烯醇（PVA）为分散剂和成核剂，采用不去除模板法合成了含有大量杂原子的三聚氰胺树脂（MR）微球，并将其与氧化石墨烯（GO）复合。使用PVA和实施冷冻处理可以防止MR球体在GO网络内团聚。采用熔融KOH实现碳化/活化/还原一步法合成DHCSs/RGO。在700 °C下退火的DHCS/RGO显示出在0.1A/g下1395 mA h/g和在5A/g下606 mA h/g的上级放电容量以及在2A/g的电流密度下600次循环后755 mA h/g的优异保持容量。额外的CO2活化导致电化学性能的进一步增强，在600次循环后，在0.1A/g下具有1709 mA h/g和在2A/g下具有835 mA h/g的出色放电容量。这项工作可能会提高我们的理解与中空和多孔碳结构的石墨烯类纳米复合材料的合成和高性能功能器件的制造。
Three-dimensional hollow carbon spheres/reduced graphene oxide (DHCSs/RGO) nanocomposites with high-level heteroatom doping and hierarchical pores are fabricated via a versatile method. Poly(vinyl alcohol) (PVA) that serves as a dispersant and nucleating agent is used as the nonremoval template for synthesizing melamine resin (MR) spheres with abundant heteroatoms, which are subsequently composited with graphene oxide (GO). Use of PVA and implementation of freezing treatment prevent agglomeration of MR spheres within the GO network. Molten KOH is used to achieve the one-step carbonization/activation/reduction for the synthesis of DHCSs/RGO. DHCSs/RGO annealed at 700 °C shows superior discharge capacity of 1395 mA h/g at 0.1 A/g and 606 mA h/g at 5 A/g as well as excellent retentive capacity of 755 mA h/g after 600 cycles at a current density of 2 A/g. An extra CO2 activation leads to further enhancement of electrochemical performance with outstanding discharge capacity of 1709 mA h/g at 0.1 A/g and 835 mA h/g at 2 A/g after 600 cycles. This work may improve our understanding of the synthesis of graphene-like nanocomposites with hollow and porous carbon architectures and fabrication of high-performance functional devices.