Boosting the Rate Performance and Capacity of Sb2S3 Nanorods Cathode by Carbon Coating in All‐Solid‐State Lithium Batteries

Abstract Antimony sulfide (Sb 2 S 3 ) is a promising electrode material. However, its poor electronic/ionic conductivity severely hinders its practical application. Herein, carbon‐coated Sb 2 S 3 nanorods (Sb 2 S 3 @C) are synthesized to address this issue. The electrochemical performance of the Sb 2 S 3 @C is evaluated in all‐solid‐state lithium batteries (ASSLBs) using InLi anode and Li 10 Si 0.3 PS 6.7 Cl 1.8 solid‐state electrolytes. The Sb 2 S 3 @C cathode delivers the 1st cycle discharge capacity of 711 mAh g ‐1 and a stable cycling capacity of 431 mAh g ‐1 , which are much higher than the 1st cycle discharge capacity of 125 mAh g ‐1 and a stable cycling capacity of 320 mAh g ‐1 for the uncoated Sb 2 S 3 cathode. In situ transmission electron microscopy reveals that the carbon coating layer acts as an electronic/ionic conductive conduit, which boosts the charge transfer in the electrode dramatically. Consequently, the Sb 2 S 3 @C electrochemistry quickly evolves from intercalation to conversion to full alloying. However, the Sb 2 S 3 nanorods without carbon coating undergo sluggish intercalation and conversion reactions, and the alloying reaction is almost impeded, severely limiting the capacity. Therefore, the Sb 2 S 3 @C electrode is fully utilized thus delivering much higher capacity and rate performance than the non‐coated Sb 2 S 3 electrode. These results demonstrate that Sb 2 S 3 @C is a promising high‐energy‐density cathode for ASSLBs.