Tailoring Sulfide Particle Size for All-Solid-State Lithium Metal Batteries.

Zhang, Ziqi; Jing, Changqing; Yao, Jingming; Wu, Yujing; Wu, Dengxu; He, Weitao; Xu, Fuqiang; Ma, Tenghuan et al. · Adv Mater · 2026

basic_science · Level V

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Abstract

The precise control of sulfide solid electrolyte (SSE) particle size distribution is crucial for constructing efficient ion-conducting networks in composite cathodes of all-solid-state lithium metal batteries (ASSLBs). This work systematically investigates the effects of key particle size parameters (D<sub>10</sub>, D<sub>50</sub>, D<sub>90</sub>) of Li<sub>6</sub>PS<sub>5</sub>Cl SSE on battery performance through controlled mechanical grinding. In this study, the optimal SSE particle size composition enables exceptional electrochemical performance of ASSLB: a high reversible capacity of 202.2 mAh/g at 0.25C, superior rate capability (76% capacity retention of 5C/0.25C), and outstanding cyclability (81.5% and 80% capacity retention after 4000 cycles at 3C and 5C, respectively). Microstructural analysis indicates that the optimized SSE particle configuration, when 7.3 ≤ D<sub>50Cathode</sub>/D<sub>50SSE</sub> and 2.0 ≤ D<sub>90Cathode</sub>/D<sub>90SSE</sub> ≤ 3.5, forms a hierarchical ion-conducting network. In this configuration, the fine particles of SSE in the composite cathode can effectively fill the cathode gaps, while the medium-sized particles can provide rapid ion transport channels, resulting in excellent rate performance and reversible capacity. Larger electrolyte particles will lead to insufficient interfacial contact and "island-like" ion transport paths. Additionally, excessively lowering D<sub>90</sub> will also result in reduced battery performance (3.5 ≤ D<sub>90C</sub>/D<sub>90SE</sub>). This study provides quantitative guiding principles for SSE particle engineering.