Communication—effect of lithium polysulfide solubility on capacity of lithium-sulfur cells

Understanding the behavior of lithium (Li)-sulfur (S) cells under lithium polysulfide (LiPS)-saturated condition, especially determining whether LiPS solubility is an intrinsic limit for cell capacity, is of great interest for the development of high energy density Li-S batteries. In this work, sets of Li-S cells were tested under designed scenarios to demonstrate the effect of LiPS solubility on cell capacity. It revealed that when LiPS solubility limit is reached, though sulfur can be reduced to solid state LiPS, it cannot further convert to subsequent discharge products and contribute to cell capacity.