A composite electrode with gradient pores for high-performance aqueous redox flow batteries

Zhang，Zhihui1,2; Zhang，Baowen3; Wei，Lei4; Lei，Yuan5; Bai，Bofeng3; Chen，Liuping6; Xu，Junhui6; Zhao，Tianshou4

2023-05-01

10.1016/j.est.2023.106755

Journal of Energy Storage   Impact Factor & Quartile

2352-152X

2352-152X

Large surface areas while maintaining a low mass transport resistance is a critical criterion for the optimal design of electrode structures for aqueous redox flow batteries. However, for conventional micro-scale electrode structures, increasing surface areas will lead to an increase in the mass transfer resistance. In this work, a composite electrode with a gradient porosity distribution is fabricated through combining two different carbon felt layers of different porosities. The smaller-porosity layer, offering a larger surface area, is placed adjacent to the membrane, while the larger-porosity layer, providing a smaller mass transfer resistance is placed on the flow field side. The thickness ratio of the two layers is adjusted in terms of the battery performance while applied in the vanadium redox flow battery. It is demonstrated that the battery with the structure-optimized composite electrode achieves a high energy efficiency of 82.7 % at 200 mA·cm at an electrolyte flow rate of 30 mL·min, and delivers a discharge capacity of 240 mAh at 400 mA·cm, which is 2.18 times that of the conventional graphite felt electrode. This work offers an idea for the structural design of high-performance aqueous redox flow batteries.

Efficiency Gradient porosity Mass transport Surface area Vanadium flow battery

SCI

English

Corresponding

National Natural Science Foundation of China[51906203] ; Natural Science Basic Research Program of Shaanxi[2021JQ-046] ; National Natural Science Founda- tion of China["2020T130529","2022M713272"] ; China Postdoctoral Science Foundation["52206089","TO2203001"]

Energy & Fuels

Energy & Fuels

WOS:000930688300001

ELSEVIER

2-s2.0-85147332904

Scopus

1.Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,China
2.BYD Auto Industry Company Limited,China
3.State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an,710049,China
4.SUSTech Energy Institute for Carbon Neutrality,Department of Mechanical and Energy Engineering,Southern University of Science and Technology,China
5.School of Chemical Engineering,Northwest University,Xi'an,710069,China
6.Jiangsu Engineering Research Center for Comprehensive Utilization of Well and Rocks Salt,Chinasalt Jintan Co.,Ltd.,Changzhou,213200,China

Zhang，Zhihui,Zhang，Baowen,Wei，Lei,et al. A composite electrode with gradient pores for high-performance aqueous redox flow batteries[J]. Journal of Energy Storage,2023,61.

Zhang，Zhihui.,Zhang，Baowen.,Wei，Lei.,Lei，Yuan.,Bai，Bofeng.,...&Zhao，Tianshou.(2023).A composite electrode with gradient pores for high-performance aqueous redox flow batteries.Journal of Energy Storage,61.

Zhang，Zhihui,et al."A composite electrode with gradient pores for high-performance aqueous redox flow batteries".Journal of Energy Storage 61(2023).