储能科学与技术 ›› 2020, Vol. 9 ›› Issue (1): 65-69.doi: 10.12028/j.issn.2095-4239.2019.0147

• 储能材料与器件 • 上一篇    下一篇

高温热处理对三维多孔石墨烯电化学性能的影响

伍世嘉1(), 肖祥1, 王超1(), 钟国彬1, 李欣1, 郑超2, 阮殿波2   

  1. 1. 广东电网有限责任公司电力科学研究院,广东 广州 510080
    2. 宁波中车新能源科技有限公司,浙江 宁波 315112
  • 收稿日期:2019-07-01 修回日期:2019-07-29 出版日期:2020-01-05 发布日期:2020-01-10
  • 通讯作者: 王超 E-mail:13920132353@163.com;wangchaomly@163.com
  • 作者简介:伍世嘉(1989—),男,博士,研究方向为电化学储能材料制备,E-mail:13920132353@163.com
  • 基金资助:
    中国南方电网有限责任公司科技项目(GDKJXM20160000)

Effect of high temperature heat treatment on electrochemical properties of three-dimensional porous graphene

Shijia WU1(), Xiang XIAO1, Chao WANG1(), Guobin ZHONG1, Xin LI1, Chao ZHENG2, Dianbo RUAN2   

  1. 1. Electric Power Research Institute of Guangdong Power Grid Co. , Ltd. , Guangzhou 510080, Guangdong, China
    2. Ningbo CRRC New Energy Technology Co. , Ltd. , Ningbo 315112, Zhejiang, China
  • Received:2019-07-01 Revised:2019-07-29 Online:2020-01-05 Published:2020-01-10
  • Contact: Chao WANG E-mail:13920132353@163.com;wangchaomly@163.com

摘要:

三维多孔石墨烯由于其独特的三维结构、高比表面积、优良的导电性能和多级孔径结构,被广泛用作超级电容器用电极材料。但目前三维多孔石墨烯的单位面积利用率仍然较低,其单位面积比容量仅有5.35 μF/cm2,远低于碳基材料的理论值(约21 μF/cm2)。为了提高三维多孔石墨烯的单位面积比容量,选择一种高比表面积的三维多孔石墨烯为研究对象,通过对其进行高温热处理,重点考察了高温热处理对三维多孔石墨烯材料导电性的影响,以及导电性能的变化对三维多孔石墨烯电化学性能的影响。研究发现高温热处理后三维石墨烯材料的比表面积由2009.8 m2/g急剧降低到1301.0 m2/g,这主要是由于高温热处理后活化石墨烯颗粒体积收缩,孔体积降低。拉曼光谱结果表明,高温热处理可以提高三维多孔石墨烯的石墨化程度,提高其导电性,EIS结果表明其等效串联内阻由处理前的4.0 Ω降低到1.4 Ω。导电性的提高使得单位面积比容量的保持率由原来的34.8%提高至45.2%,这表明三维多孔石墨烯的单位面积利用率得到明显提升。研究结果为三维多孔石墨烯电极材料的可控制备提供理论依据。

关键词: 三维多孔石墨烯, 超级电容器, 热处理, 电化学性能

Abstract:

Three-dimensional porous graphene (TDPG) is extensively used as an electrode material for supercapacitors because of its unique three-dimensional structure, high specific surface area, high conductivity, and multilevel pore diameters. However, the specific capacitance per unit area of TDPG is only approximately 5.35 μF/cm2, which is considerably lower than the theoretical value of a carbon-based material (~21 μF/cm2). A TDPG with a high specific surface area was selected for this study to improve the specific capacitance per unit area. The effect of high-temperature heat treatment on the conductivity of TDPG was investigated along with the effect of the changes in conductivity on its electrochemical properties. The results denoted that the specific surface area of TDPG was drastically reduced from 2009.8 to 1301.0 m2/g after the high-temperature heat treatment, which was mainly due to the shrinkage of the graphene particles and the reduction of pore volume. The Raman spectrum results demonstrated that high-temperature heat treatment could improve the degree of graphitization of TDPG and increase the conductivity of the electrode materials. Electron impact spectroscopy verified that the equivalent series internal resistance of button supercapacitors with TDPG as the electrode was reduced from 4.0 Ω to 1.4 Ω after heat treatment. The increase in conductivity helped to increase the specific capacity retention rate from 34.8% to 45.2%, indicating that the specific capacitance per unit area of TDPG was considerably improved by high-temperature heat treatment. The study provides a theoretical basis for the controllable preparation of the TDPG electrode materials.

Key words: three-dimensional porous graphene, supercapacitor, high temperature heat treatment, electrochemical properties

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