储能科学与技术 ›› 2020, Vol. 9 ›› Issue (3): 714-719.doi: 10.19799/j.cnki.2095-4239.2020.0019

• 未来科学城储能技术专刊 • 上一篇    下一篇

全钒液流电池碳纤维纸电极的表面改性

王秋实(), 孙苗苗, 刘庆华, 杨虹, 陈静允, 刘均庆, 梁文斌   

  1. 北京低碳清洁能源研究院，北京 102211
  • 收稿日期:2020-01-07 修回日期:2020-03-11 出版日期:2020-05-05 发布日期:2020-05-11
  • 作者简介:王秋实（1985—），男，博士，研究方向为液流电池，储热材料，E-mail: qiushi.wang@chnenergy.com.cn。

Surface modification of carbon fiber paper for vanadium redox flow battery

WANG Qiushi(), SUN Miaomiao, LIU Qinghua, YANG Hong CHEN Jingyun, LIU Junqing, LIANG Wenbin   

  1. National Institute of Clean and Low Carbon Energy, Beijing 102211, China
  • Received:2020-01-07 Revised:2020-03-11 Online:2020-05-05 Published:2020-05-11

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摘要：

采用浸渍和碳化的方法将液流电池碳纤维纸电极与多壁碳纳米管（MWCNT）复合，制备了复合电极材料。通过循环伏安（CV）、交流阻抗（EIS）、单电池测试、扫描电子显微技术(SEM)、电子能谱分析技术(XPS)、比表面积分析技术(BET)等手段对复合电极进行了测试和电化学性能表征分析。结果表明，同未改性电极相比复合电极中碳纤维和MWCNT之间的结合力强，电极亲水性从疏水变成亲水；电阻率从12.5 Ω·cm2 下降到0.74 Ω·cm2；比表面积从2 m2/g增加到99 m2/g。改性后的复合电极电化学反应活性高、循环性能好、电子迁移速度快，多壁碳纳米管在电极表面形成了纳米网络结构增大了电解液中活性物质与电极的反应面积，同时也降低了电池的内阻，增加了传质速度。对组装的单电池在电流密度为100～400 mA/cm2进行充放电测试，发现能量效率在200 mA/cm2的充放电电流下保持在80%以上，功率密度可以达603.32 mW/cm2。本研究有助于推动多壁碳纳米管改性电极的大规模商业化应用，为进一步降低生产升本提供实验数据支持。

关键词: 全钒液流电池, 碳纸, 电极, 表面改性

Abstract:

Composite carbon fiber electrodes were manufactured by attaching multi-walled carbon nanotubes (MWCNTs) to carbon paper (CP) using the impregnation and carbonization method. The binder between the carbon fiber surface and MWCNT was carbonized to increase the bonding strength and lower the electrical resistance. The composite electrode was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, the BrunauerEmmettTeller specific surface area, cyclic voltammetry, and electrochemical impedance spectroscopy. The composite CP/MWCNT electrodes demonstrated higher surface area (99 m2/g), higher electrochemical activity, lower electrical resistance (0.74 Ω·cm2), and greater hydrophilicity than CP. The CP/MWCNT possessed chemically reactive sites and low charge-transfer resistance and achieved higher energy-conversion efficiency than CP in electrochemical tests. The energy efficiency was maintained at 80% under a chargedischarge current density of 200 mA/cm2 and its peak power density reached 603.32 mW/cm2. This excellent electrochemical performance is mainly attributed to the MWCNT nanostructure formed on the carbon fiber surface. The presented results could pave the way for low-cost electrode manufacturing.

Key words: vanadium redox flow battery, carbon paper, electrode, surface modification

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