Ni (OH)2-碳纳米管-还原氧化石墨烯复合材料的制备及电化学性能

利用简单易行的一步水热法制备了Ni（OH）₂-碳纳米管-还原氧化石墨烯（Ni（OH）₂-CNTs-RGO）三元复合材料，研究了不同水热反应温度对三元复合材料性能的影响。采用XRD、FTIR、Raman、X射线光电子能谱（XPS）、SEM及TEM对Ni（OH）₂-CNTs-RGO复合材料的结构和表面微观形貌进行表征。利用循环伏安（CV）、电化学交流阻抗（EIS）和恒电流充放电测试了复合电极材料的电化学性能。研究结果表明，当反应温度为120℃时，所制备的Ni（OH）₂-CNTs-RGO复合材料具有大的比表面积和三维网状结构，复合材料中六角形的β-Ni（OH）₂纳米片和CNTs均匀分散在RGO片层表面，有效阻止了RGO的团聚。Ni（OH）₂-CNTs-RGO复合电极材料在充电倍率为0.2 C时，放电比容量达到362.8 mAh/g，5 C时放电比容量为286.2 mAh/g，仍大于Ni（OH）₂在0.2 C时的放电比容量，表明CNTs与RGO的协同作用有效提高了电极材料的导电性和活性物质的利用率，最终提升了Ni（OH）₂-CNTs-RGO复合材料的倍率性能。

Preparation and electrochemical properties of Ni(OH)2-carbon nanotubes-reduced graphene oxide composites

Ni(OH)₂-carbon nanotubes-reduced graphene oxide (Ni(OH)₂-CNTs-RGO) ternary composites were synthesized by simple and practicable one-pot hydrothermal synthesis method. The influence of different reaction temperatures on properties of composite materials was researched. The microstructure and morphology of Ni(OH)₂-CNTs-RGO composites were characterized by XRD, FTIR, Raman spectroscopy, X-ray photoelectron spectroscopy(XPS), SEM and TEM. The electrochemical characteristics of Ni(OH)₂-CNTs-RGO electrode composites were tested by cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge. The results show that the prepared Ni(OH)₂-CNTs-RGO composite has large specific surface area and 3D network structure when the reaction temperature is 120℃. The synthesized Ni(OH)₂-CNTs-RGO composite shows that hexagonal β-Ni(OH)₂ nano sheets and CNTs are homogeneously dispersed and inserted into RGO sheets. The Ni(OH)₂-CNTs-RGO electrode composite exhibits the discharge specific capacity up to 362.8 mAh/g at 0.2 C and 286.2 mAh/g at 5 C, which is still higher than the specific capacity of Ni(OH)₂. The CNTs and RGO collaborative role effectively improves the conductivity of the electrode material and the utilization of active material. Finally, the rate performance of Ni(OH)₂-CNTs-RGO composite is improved.