Precipitation–Microstructure Interactions in the Li-Sulfur Battery Electrode

Formation and precipitation of insulating discharge products, such as Li2S, in the lithium–sulfur (Li–S) battery cathode, leads to deleterious performance decay. Physicochemical interactions underlying the cathode microstructure evolution due to precipitation are hitherto poorly understood. In this work, a mesoscale understanding of the microstructure–precipitate interplay owing to surface passivation and pore blockage is presented. Mesoporous, carbon-based cathode microstructures are examined for disparate precipitate morphology and growth. The pore-scale manifestation of the microstructural and transport limitations on the electrochemical performance is elucidated. Surface passivation and pore blockage effects are examined for complexations due to sulfur loading, electrolyte volume, pore size, and precipitate morphology. This study provides critical insights into the underlying mesoscale physics and microstructural stochasticity on the Li–S battery performance.