US Patent 11973254 Aqueous polysulfide-based electrochemical cell

An electrochemical cell and battery system including cells, each cell including a catholyte, an anolyte, and a separator disposed between the catholyte and anolyte and that is permeable to the at least one ionic species (for example, a metal cation or the hydroxide ion). The catholyte solution includes a ferricyanide, permanganate, manganate, sulfur, and/or polysulfide compound, and the anolyte includes a sulfide and/or polysulfide compound. These electrochemical couples may be embodied in various physical architectures, including static (non-flowing) architectures or in flow battery (flowing) architectures.