RGO@CoNd-LDH复合材料的制备与电化学性能

Preparation and Electrochemical Properties of the RGO@CoNd-LDH Composites

摘要: 通过简单易操作的水热法来制备石墨烯(RGO)/钴钕双金属氢氧化物纳米复合材料，探究钕金属、钴金属和钴钕双金属与RGO的最佳性能，并且通过不断改变钴钕双金属中钴钕之间的摩尔比，来获得形貌微调可控的物质，使钴钕相互之间发挥最有利的优势。有效地解决了过渡金属化合物的导电率差、比表面积低、活性物质易团聚等问题。利用扫描电镜、透射电镜、红外、XRD、XPS、EDS能谱点扫、电化学测试等测试对复合电极材料进行分析。结果表明RGO@CoNd呈现珊瑚状结构，包覆在石墨烯表面。RGO@CoNd其在1 A/g的电流密度时比电容为1054 F/g，与RGO/CoNd₄、RGO/Co₂Nd₃、RGO/Co₃Nd₂、RGO/Co₄Nd相比，RGO/CoNd的比电容分别增加了66.6%、67.4%、47.9%、115%。在10 A/g电流密度下4000次充放电循环后比电容保持率为93.9%，具有良好的循环稳定性。结果表明，RGO/CoNd复合材料是很有前途的超级电容器电极材料。

Abstract: Graphene (RGO)/CoNd bimetallic hydroxide nanocomposites were prepared by a simple and easy-to-operate hydrothermal method to explore the optimal properties of Nd metal, cobalt metal, and cobalt-Nd bimetallic with RGO, and to obtain morphology fine-tuned and controllable substances by constantly changing the molar ratio between cobalt and Nd in the cobalt-Nd bimetallic, so as to enable cobalt and Nd to exert the most advantageous advantages over each other. The problems of poor electrical conductivity, low specific surface area and easy agglomeration of active substances in transition metal compounds are effectively solved. The composite electrode materials were analyzed using tests such as scanning electron microscopy, transmission electron microscopy, infrared, XRD, XPS, EDS energy spectrum spot scanning, and electrochemical tests. The results show that RGO@CoNd presents a coral-like structure, which is encapsulated on the surface of graphene. The specific capacitance of RGO@CoNd whose specific capacitance is 1054 F/g at a current density of 1 A/g is increased by 66.6% compared with that of RGO/CoNd₄, RGO/Co₂Nd₃, RGO/Co₃Nd₂, and RGO/Co₄Nd, respectively, 67.4%, 47.9%, and 115%, respectively. The specific capacitance retention rate was 93.9% after 4000 charge/discharge cycles at 10 A/g current density, which showed good cycling stability. The results show that RGO/CoNd composites are promising electrode materials for supercapacitors.