Percin Korcan, van der Zee Bart, Wessling Matthias
DWI-Leibniz Institute for Interactive Materials Forckenbeckstr. 50 52074 Aachen Germany.
RWTH Aachen University Aachener Verfahrenstechnik-Chemical Process Engineering Forckenbeckstr. 51 52074 Aachen Germany.
ChemElectroChem. 2020 May 4;7(9):2165-2172. doi: 10.1002/celc.202000242. Epub 2020 May 7.
We studied the half-cell performance of a slurry-based vanadium redox flow battery via the polarization and electrochemical impedance spectroscopy methods. First, the conductive static mixers are examined and lower ohmic and diffusion resistances are shown. Further analyses of the slurry electrodes for the catholyte (VO-VO ) and anolyte (V-V) are presented for the graphite powder slurry containing up to 15.0 wt.% particle content. Overall, the anolyte persists as the more resistive half-cell, while ohmic and diffusion-related limitations are the dominating resistances for both electrolytes. The battery is further improved by the addition of Ketjen black nanoparticles, which results in lower cell resistances. The best results are achieved when 0.5 wt.% Ketjen black nanoparticles are dispersed with graphite powder since the addition of nanoparticles reduces ohmic, charge transfer and mass diffusion resistances by improving particle-particle dynamics. The results prove the importance of understanding resistances in a slurry electrode system.
我们通过极化和电化学阻抗谱方法研究了基于浆料的钒氧化还原液流电池的半电池性能。首先，对导电静态混合器进行了检查，并显示出较低的欧姆电阻和扩散电阻。对于颗粒含量高达15.0 wt.%的石墨粉浆料，进一步分析了阴极电解液（VO-VO ）和阳极电解液（V-V）的浆料电极。总体而言，阳极电解液仍然是电阻较大的半电池，而欧姆电阻和扩散相关的限制是两种电解液的主要电阻。通过添加科琴黑纳米颗粒进一步改善了电池性能，这导致电池电阻降低。当0.5 wt.%的科琴黑纳米颗粒与石墨粉分散在一起时可获得最佳结果，因为纳米颗粒的添加通过改善颗粒间动力学降低了欧姆电阻、电荷转移电阻和质量扩散电阻。结果证明了理解浆料电极系统中电阻的重要性。
