Energy Storage Science and Technology ›› 2024, Vol. 13 ›› Issue (2): 381-389.doi: 10.19799/j.cnki.2095-4239.2023.0607

• Energy Storage Materials and Devices • Previous Articles     Next Articles

Fabrication of metal-organic framework-derived C-Bi/CC electrode materials and their electrochemical properties in ICRFB

Yang ZHOU(), Peiyu HAN, Yingchun NIU, Chunming XU, Quan XU()   

  1. China University of Petroleum, Beijing 102249, China
  • Received:2023-09-05 Revised:2023-10-23 Online:2024-02-28 Published:2024-03-01
  • Contact: Quan XU E-mail:zhouyang@cup.edu.cn;xuquan@cup.edu.cn

Abstract:

The electrode is an important part of the iron-chromium flow battery, serving as the site where the active components in the electrolyte undergo electrochemical reactions. The ideal electrode material should have high conductivity, large specific surface area, high electrochemical activity, low cost, among other characteristics. However, current electrode materials often lack a balance of these characteristics. Metal-organic frameworks (MOFs) combine their advantages of high conductivity and high catalytic performance, providing additional active sites for electrochemical reactions and finding widespread use in electrode materials. Herein, bismuth-based carbon cloth (CC) electrodes (C-Bi/CC) with carbon cloth-supported Bi-MOF as a precursor (Bi-MOF/CC) were prepared using a hydrothermal method. The electrode performance was improved by exploring the coupling correlation between the addition of metal salts and the electrode performance. The results showed that the electrode sample using 90 mg of metal salt and the ordinary carbon cloth as the positive electrode exhibited the best electrochemical performance, with a reduced polarization resistance of 1.069 Ω (an 8.5% reduction), an enhanced electrochemical active area, a low Cr3+ reduction overpotential of 0.25 V (a 59.7% decrease). The modified electrode was used as the negative electrode of the iron-chromium flow battery for the battery cycling performance test. At a current density of 80 mA/cm2, the energy efficiency reached 89.7%, the Coulombic efficiency was 97.2%, and the voltage efficiency was 92.3%. At a current density of 140 mA/cm2, the energy efficiency remained high at 83.8%, with the Coulomb efficiency reaching 98.1% and the voltage efficiency reaching 85.5%.

Key words: iron-chromium flow batteries, electrode material, electrochemical performance, energy efficiency

CLC Number: