Lithium–sulfur batteries use a solid electrolyte as an alternative to the conventional liquid electrolyte to form solid-state lithium–sulfur cells with a high energy density. Sulfur cathodes are the common active material used in conjunction with solid electrolytes. However, their insulating nature and the solid–solid interface with the solid electrolyte result in poor cyclability and low active material loading. In this study, we adopt a polysulfide cathode and a sulfide solid electrolyte to generate a novel lithium-sulfur cell configuration. The liquid–solid interface provided by the polysulfide catholyte allows a close connection between the electrode and electrolyte, enhancing charge transfer and lithium-ion diffusion. The improved interface means that the polysulfide cathode exhibits high reactivity, allowing us to achieve a high sulfur loading (5 mg cm⁻²), a high areal capacity (5.1 mA h cm⁻²), and a long cycle life (approaching 100 cycles). X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy confirm the formation of lithium phosphide and lithium phosphate on the cathode side of the electrolyte. These compounds form an ionically conductive protection layer that optimizes the contact between the polysulfide cathode and the solid electrolyte and stabilizes the active electrodes, thereby enhancing the kinetics and stability of the electrochemical reaction.

中文翻译：

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具有硫化物固体电解质/多硫化物阴极界面的锂硫电池

锂硫电池使用固体电解质作为传统液体电解质的替代品，形成具有高能量密度的固态锂硫电池。硫阴极是与固体电解质结合使用的常见活性材料。然而，它们的绝缘性和与固体电解质的固-固界面导致循环性能差和活性材料负载量低。在这项研究中，我们采用多硫化物阴极和硫化物固体电解质来产生一种新型锂硫电池结构。多硫化物阴极电解液提供的液-固界面允许电极和电解质之间的紧密连接，增强电荷转移和锂离子扩散。改进的界面意味着多硫化物正极表现出高反应性，^-2）、高面积容量（5.1 mA h cm ^-2）和长循环寿命（接近100次循环）。X 射线光电子能谱和飞行时间二次离子质谱证实在电解液的阴极侧形成了磷化锂和磷酸锂。这些化合物形成离子导电保护层，优化多硫化物阴极和固体电解质之间的接触并稳定活性电极，从而提高电化学反应的动力学和稳定性。