Understanding the Impact of Precipitation Kinetics on the Electrochemical Performance of Lithium–Sulfur Batteries by Operando X-ray Diffraction

• The complex reaction mechanism of the lithium–sulfur battery system consists of re-petitive dissolution and precipitation of the sulfur-containing species in the positiveelectrode. In particular, the precipitation of lithium sulfide (Li2S) during discharge hasbeen considered a crucial factor for achieving a high degree of active material utiliza-tion. Here, the influence of electrolyte amount, electrode thickness, applied current andelectrolyte salt on the formation of Li2S is systematically investigated in a series ofoperando X-ray diffraction experiments. Through a combination of simultaneous dif-fraction and resistance measurements, the evolution of the intensity from Li2S is di-rectly correlated to the variation in internal resistance and transport properties insidethe positive electrode. The correlation indicates that at different stages, the Li2S precip-itation both facilitates and impedes the discharge process. The kinetic information ofLi2S formation offers mechanistic explanations for the strong impact of different elec-trochemical cell parameters on the performance and thus, directions for holistic optimi-zations to achieve high sulfur utilization.

Ämnesord

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)