Remediation of shuttle effect in a Li-sulfur battery via a catalytic pseudo-8-electron redox reaction at the sulfur cathode

•A novel catalytic process for the disproportionation of dissolved polysulfides was discovered.•A pseudo-8-electron sulfur redox reaction mechanism was postulated.•The presence of dissolved polysulfides in the electrolyte was significantly reduced.•Efforts to mitigate the polysulfide shuttle phenomenon were successful. A catalytic pseudo-8-electron redox reaction of sulfur is achieved by facilitating the disproportionation of high-order polysulfide ions in a Li-Sulfur battery. Electrochemically generated polysulfide ions (Sx2-, where 3