Progress in lithium-sulfur batteries: the effective role of a polysulfide-added electrolyte as buffer to prevent cathode dissolution.

Paving the road for sulfur: A unique electrolyte composition designed for the development of stable lithium-sulfur batteries with high energy. A battery with a high and stable capacity is prepared by using an electrolyte containing a dissolved catholyte-type compound, that is, Li2 S8 polysulfide. The cell is characterized by a capacity approaching the theoretical value at a working voltage of 2.1 V, which is remarkable compared to conventional lithium ion batteries.