物理化学学报 >> 2020, Vol. 36 >> Issue (7): 1907072.doi: 10.3866/PKU.WHXB201907072

所属专题: 纳米复合材料

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用于超级电容器的锰钴氧化物/碳纤维材料

王玖,吴南石,刘涛,曹少文*(),余家国*()   

  • 收稿日期:2019-07-25 录用日期:2019-09-11 发布日期:2019-09-24
  • 通讯作者: 曹少文,余家国 E-mail:swcao@whut.edu.cn;jiaguoyu@yahoo.com; yujiaguo93@whut.edu.cn
  • 基金资助:
    国家自然科学基金(51922081);国家自然科学基金(21773179);国家自然科学基金(U1705251);国家自然科学基金(21433007);湖北自然科学基金(2017CFA031);中央高校本科研业务费专项基金(WUT: 2019-Ⅲ-196)

MnCo Oxides Supported on Carbon Fibers for High-Performance Supercapacitors

Jiu Wang,Nanshi Wu,Tao Liu,Shaowen Cao*(),Jiaguo Yu*()   

  • Received:2019-07-25 Accepted:2019-09-11 Published:2019-09-24
  • Contact: Shaowen Cao,Jiaguo Yu E-mail:swcao@whut.edu.cn;jiaguoyu@yahoo.com; yujiaguo93@whut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(51922081);the National Natural Science Foundation of China(21773179);the National Natural Science Foundation of China(U1705251);the National Natural Science Foundation of China(21433007);the Natural Science Foundation of Hubei Province, China(2017CFA031);the Fundamental Research Funds for the Central Universities, China(WUT: 2019-Ⅲ-196)

摘要:

设计开发高性能超级电容器的电极材料是缓解当代能源危机的迫切需要。本研究工作采用简单的水热法并结合后续煅烧处理的方法制备了锰钴氧化物与碳纤维的复合材料。该方法制备的复合材料中的锰钴氧化物可以均匀地分散在碳纤维表面,从而增加了电极材料与电解质的界面接触,提高了电极材料的利用率。因此,锰钴氧化物材料上可发生完全的赝电容反应。而且,碳纤维的加入降低了材料的电阻,使得锰钴氧化物与碳纤维的复合材料具有良好的电容性能。在电流密度为2 A∙g-1时,电容可达854 F∙g-1。在此条件下,2000次循环后,电容仍可维持在72.3%。因此,碳纤维负载锰钴氧化物的复合材料可用于提高超级电容器的电化学性能,并为制备高性能超级电容器的电极材料提供了新的策略。

关键词: 锰钴氧化物, 碳纤维, 超级电容器, 复合材料, 接触

Abstract:

The development of high-performance supercapacitor electrode materials is imperative to alleviate the ongoing energy crisis. Numerous transition metals (oxides) have been studied as electrode materials for supercapacitors owing to their low cost, environmental-friendliness, and excellent electrochemical performance. Among the developed binary transition metal oxides, manganese cobalt oxides typically show high theoretical capacitance and stable electrochemical performance, and are widely used in the electrode materials of supercapacitors. However, the poor conductivity and active material utilization of manganese cobalt oxide-based electrode materials limit their potential capacitance application. Cotton is mainly composed of organic carbon-containing materials, which can be transformed to carbon fibers after calcination. The resultant carbonaceous material exhibits a large specific surface area and good conductivity. Such advantages could potentially suppress the negative effects caused by the poor conductivity and small specific surface area of manganese cobalt oxides, thereby improving the electrochemical performance. Herein, we firstly deposited manganese cobalt oxides on cotton by a simple hydrothermal method, yielding a composite of manganese cobalt oxides and carbon fibers via subsequent calcination, to improve the electrochemical performance of the electrode material. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), and electrochemical characterizations were used to investigate the physical, chemical, and electrochemical properties of the prepared samples. The fabricated manganese cobalt oxides in the composite were uniformly dispersed on the carbon fiber surface, which increased the contact between the interface of the electrode material and electrolyte, and enhanced electrode material utilization. The electrode material was confirmed to have well contacted with the electrolyte during a contact angle test. Hence, a pseudo-capacitance reaction completely occurred on the manganese cobalt oxide material. Moreover, the addition of carbon fibers reduced the resistance of the material, resulting in excellent capacitive performance. The capacitance of the prepared composite was 854 F∙g-1 at a current density of 2 A∙g-1. The capacitance was maintained at 72.3% after 2000 cycles at a current density of 2 A∙g-1. These results indicate that the manganese cobalt oxide and carbon fiber composite is a promising electrode material for high-performance supercapacitors. The findings presented herein provide a strategy for coupling with carbon materials to enhance the performance of supercapacitor electrode materials based on manganese cobalt oxides. Thus, novel insights into the design of high-performance supercapacitors for energy management are provided.

Key words: Manganese cobalt oxide, Carbon fiber, Supercapacitor, Composite, Contact

MSC2000: 

  • O643