Lithium–sulfur (Li–S) batteries have long been expected to be a promising high-energy-density secondary battery system since their first prototype in the 1960s. During the past decade, great progress has been achieved in promoting the performances of Li–S batteries by addressing the challenges at the laboratory-level model systems. With growing attention paid to the application of Li–S batteries, new challenges at practical cell scales emerge as the bottleneck. In this Outlook, the key parameters for practical Li–S batteries to achieve practical high energy density are emphasized regarding high-sulfur-loading cathodes, lean electrolytes, and limited excess anodes. Subsequently, the key scientific problems are redefined in practical Li–S batteries beyond the previous ones under ideal conditions. Finally, viable strategies are proposed to address the above challenges as future research directions.

中文翻译：

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实用锂硫电池的前景。

自1960年代首个原型以来，人们一直期待锂硫（Li–S）电池成为有前途的高能量密度二次电池系统。在过去的十年中，通过解决实验室级模型系统面临的挑战，在提升Li-S电池性能方面取得了巨大进展。随着对Li-S电池应用的关注日益增加，实际电池规模的新挑战成为瓶颈。在此展望中，针对高硫负载阴极，稀薄电解质和有限的过量阳极，强调了实用的Li-S电池实现实用的高能量密度的关键参数。随后，在理想条件下，实际锂-锂电池的关键科学问题被重新定义，超越了以往的锂-锂电池。最后，