Li–Se battery: absence of lithium polyselenides in carbonate based electrolyte

Abstract

The lithiation mechanism of the Li–Se cell in a carbonate-based electrolyte is discussed. It is found that Se is directly reduced to Li₂Se in discharge without intermediate phases detected by in situ X-ray diffraction or X-ray absorption spectroscopy. The reason is that the redox products Se and Li₂Se, as well as lithium polyselenides are insoluble in the electrolyte.