All-solid-state batteries (ASSBs) containing solid electrolytes can offer high energy density and enhanced safety compared to conventional Li-ion batteries. Among solid electrolytes, sulfide-based materials have garnered significant attention owing to their high ionic conductivity and facile processability. In this study, Li argyrodite solid electrolytes containing both BH₄⁻ and Br⁻ anions were prepared using a straightforward two-step milling method without heat treatment. The synthesized materials exhibited an impressive ionic conductivity of up to 14.4 mS cm⁻¹ at room temperature, which surpassed previously reported values of borohydride-substituted argyrodite electrolytes. To elucidate the effect of Br⁻ anion replacement in the thiophosphate local structure, Raman and ³¹P solid-state nuclear magnetic resonance spectroscopic analyses were performed. The results showed that the total proportion of the PS₄³⁻ units in the argyrodite phase, including both BH₄⁻ and Br⁻ anions, determined the Li ionic conductivity of the solid electrolytes. The prepared solid electrolyte samples were stable up to 5 V vs. Li⁺/Li without any notable side reactions. The rate performance of the ASSBs, including both the Br⁻ and BH₄⁻-substituted solid electrolytes, was superior to that of the cell with the BH₄⁻-substituted solid electrolyte.

中文翻译：

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用于全固态电池的溴化物和硼氢化物阴离子增强锂银汞矿固体电解质的离子电导率


与传统锂离子电池相比，含有固体电解质的全固态电池（ASSB）可以提供高能量密度和更高的安全性。在固体电解质中，硫化物基材料由于其高离子电导率和易于加工性而受到广泛关注。在这项研究中，使用简单的两步研磨方法制备了同时含有 BH ₄ ^-和 Br ^-阴离子的锂硫银矿固体电解质，无需热处理。合成的材料在室温下表现出高达14.4 mS cm ^-1的令人印象深刻的离子电导率，超过了先前报道的硼氢化物取代的银汞矿电解质的值。为了阐明硫代磷酸盐局部结构中 Br ^-阴离子取代的影响，进行了拉曼和³¹ P 固态核磁共振波谱分析。结果表明，银汞矿相中PS ₄ ³⁻单元的总比例（包括BH ₄ ^-和Br ^-阴离子）决定了固体电解质的Li 离子电导率。所制备的固体电解质样品相对于Li ⁺ /Li 在高达 5 V 的电压下稳定，没有任何明显的副反应。 包括Br ^-和BH ₄ ^-取代固体电解质的ASSB的倍率性能优于具有BH ₄ ^-取代固体电解质的电池。