Challenges and development of composite solid-state electrolytes for high-performance lithium ion batteries

The safety concerns and the pursuit of high energy density have stimulated the development of high-performance solid-state lithium ion batteries. Therefore, the key component in solid-state lithium batteries, i.e. the solid-state electrolytes, also has attracted tremendous attention due to its non-flammability and good adaptability to high-voltage cathodes/lithium metal anodes. An in-depth understanding of the existing problems of solid-state electrolytes and proposed strategies for addressing these problems is crucial for the efficient design of high-performance solid-state electrolytes. In this review, we systematically summarized the current limitations of composite solid-state electrolytes and efforts to overcome them, and gave some proposals for the future perspectives of solid-state electrolytes with the aim to provide practical guidance for the researchers in this area.