The invention belongs to the technical field of flow batteries, and relates to an
electrolyte containing a polyanionic
electrolyte additive and a
flow battery. Comprising a
viologen compound, a
supporting electrolyte, a
solvent and a polyanionic
electrolyte additive, the polyanionic electrolyte additive accounts for 0.1%-20% of the electrolyte in percentage by
mass; molecules of the polyanionic electrolyte additive are rich in various functional groups with negative charges, and the polyanionic electrolyte additive is used for interfering the pi-pi accumulation behavior of
viologen molecules; the polyanionic electrolyte additive is a
polymer containing a repetitive unit, and is
sodium polystyrenesulfonate,
sodium polyacrylate, poly (2-acrylamido-2-methyl
sodium propanesulfonate) or
sodium alginate. By introducing a
polymer carrying high-density negative charges in the structure or aggregated inorganic anions, multiple regulation and control effects on
viologen molecules in a water-phase environment are realized, aggregation behaviors of reduced molecules of the viologen molecules are remarkably inhibited, and chemical and electrochemical stability of the electrolyte is improved.