All-solid-state lithium ion batteries (ASSLBs) are considered next-generation devices for energy storage due to their advantages in safety and potentially high energy density. As the key component in ASSLBs, solid-state electrolytes (SSEs) with non-flammability and good adaptability to lithium metal anodes have attracted extensive attention in recent years. Among the current SSEs, composite solid-state electrolytes (CSSEs) with multiple phases have greater flexibility to customize and combine the advantages of single-phase electrolytes, which have been widely investigated recently and regarded as promising candidates for commercial ASSLBs. Based on existing investigations, herein, we present a comprehensive overview of the recent developments in CSSEs. Initially, we introduce the historical development from solid-state ionic conductors to CSSEs, and then summarize the fundamentals including mechanisms of lithium ion transport, key evaluation parameters, design principles, and key materials. Four main types of advanced structures for CSSEs are classified and highlighted according to the recent progress. Moreover, advanced characterization and computational simulation techniques including machine learning are reviewed for the first time, and the main challenges and perspectives of CSSEs are also provided for their future development.

中文翻译：

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锂电池复合固态电解质的综述：基本原理，关键材料和先进结构

由于全固态锂离子电池（ASSLB）在安全性和潜在的高能量密度方面的优势，它们被视为下一代能量存储设备。作为ASSLB中的关键成分，近年来，具有不燃性和对锂金属阳极的良好适应性的固态电解质（SSE）引起了广泛的关注。在当前的SSE中，具有多相的复合固态电解质（CSSE）具有更大的灵活性来定制和组合单相电解质的优点，最近已对其进行了广泛研究，并被认为是商用ASSLB的有希望的候选者。在此基础上，根据现有调查，我们对CSSE的最新发展进行了全面概述。首先，我们介绍从固态离子导体到CSSE的历史发展，然后总结了基本原理，包括锂离子迁移的机理，关键的评估参数，设计原理和关键的材料。根据最近的进展，对CSSE的四种主要高级结构类型进行了分类和突出显示。此外，首次对包括机器学习在内的高级表征和计算仿真技术进行了首次综述，并且还为CSSE的未来发展提供了主要挑战和观点。