Theoretical and Experimental Investigation of Functionalized Cyanopyridines Yield an Anolyte with an Extremely Low Reduction Potential for Nonaqueous Redox Flow Batteries.

ABSTRACT: Cyanopyridines and cyanophenylpyridines were investigated as anolytes for nonaqueous redox flow batteries (RFBs). The three isomers of cyanopyridine are reduced at potentials of -2.2 V or lower vs. ferrocene^+/0 (Fc^+/0 ), but the 3-CNPy⋅^- radical anion forms a sigma-dimer that is re-oxidized at E≈-1.1 V, which would lead to poor voltaic efficiency in a RFB. Bulk electrochemical charge-discharge cycling of the cyanopyridines in acetonitrile and 0.50 M [NBu₄ ][PF₆ ] shows that 2-CNPy and 4-CNPy lose capacity quickly under these conditions, due to irreversible chemical reaction/decomposition of the radical anions. Density-functional theory (DFT) calculations indicated that adding a phenyl group to the cyanopyridines would, for some isomers

SUBMITTER: Vaid TP 

PROVIDER: S-EPMC10092174 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature