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

ABSTRACT: 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, e

SUBMITTER: Ma K 

PROVIDER: S-EPMC6872572 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature