Details

Autor(en) / Beteiligte

• Ma, Kaijie
• Zhang, Yunong
• Liu, Le
• Xi, Jingyu
• Qiu, Xinping
• Guan, Tian
• He, Yonghong

Titel

In situ mapping of activity distribution and oxygen evolution reaction in vanadium flow batteries

Ist Teil von

• Nature communications, 2019-11, Vol.10 (1), p.5286-11, Article 5286

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Understanding spatial distribution difference and reaction kinetics of the electrode is vital for enhancing the electrochemical reaction efficiency. Here, we report a total internal reflection imaging sensor without background current interference to map local current distribution of the electrode in a vanadium redox flow battery during cyclic voltammetry (CV), enabling mapping of the activity and reversibility distribution with the spatial resolution of a single fiber. Three graphite felts with different activity are compared to verify its feasibility. In long-term cyclic voltammetry, the oxygen evolution reaction is proved to enhance activity distribution, and homogeneity of the electrode and its bubble kinetics with periodic fluctuation is consistent with the cyclic voltammetry curve, enabling the onset oxygen evolution/reduction potential determination. Higher activity and irreversibility distribution of the electrode is found in favor of the oxygen evolution reaction. This sensor has potential to detect in situ, among other processes, electrochemical reactions in flow batteries, water splitting, electrocatalysis and electrochemical corrosion.