“…In the past, many BCAs have been evaluated for their application on zinc bromine batteries, out of which BCAs such as 1-ethyl-1-methylpyrrolidin-1-ium bromide [MEP]Br and 1-ethyl-1-methylmorpholin-1-ium bromide [MEM]Br [ 8 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 38 , 39 , 42 , 43 ] have received a lot of attention and have been investigated thoroughly. Other BCA structures such as heteroaromatic BCAs based on alkylated pyridine, picolines or imidazole [ 27 , 29 , 30 , 34 , 44 ], symmetrical and unsymmetrical alkylated aliphatic BCAs [ 33 , 40 , 42 ] and alkylated cyclic cations [ 27 , 29 , 36 , 42 ] have also been reported in the literature. Different side chains in N-position such as n -alkyl [ 27 , 29 , 31 , 33 , 34 , 36 ] or iso -alkyl groups [ 31 ] have been used to investigate their steric influence on melting point, complexation and solubility of the fused salt in Zn/Br 2 -electrolytes.…”