Covalent organic framework-based solid-state electrolytes for lithium metal batteries: from materials to applications

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid-state lithium metal batteries (SSLMBs) offer enhanced safety and energy density but face challenges with solid-state electrolytes (SSEs).
• Key limitations of current SSEs include low room-temperature ionic conductivity and poor interfacial stability.
• Covalent organic frameworks (COFs) are emerging as promising materials for SSEs due to their ordered structures and stability.

Purpose of the Study:

• To review recent advancements in using covalent organic frameworks (COFs) in solid-state electrolytes (SSEs) for SSLMBs.
• To highlight the advantages of COFs in enhancing ionic conductivity, lithium-ion transference number, and interfacial stability.
• To summarize strategies for improving COF-based SSE performance and outline future research directions.

Main Methods:

• Review of existing literature on COFs applied as single solid electrolytes and composite solid electrolytes.
• Analysis of COF properties, including pore structure, functional groups, and chemical stability, in relation to SSE performance.
• Identification of key strategies in material design, structural regulation, and interface engineering for COF-based SSEs.

Main Results:

• COFs demonstrate significant potential in improving ionic conductivity and lithium-ion transference numbers in SSEs.
• COFs facilitate the construction of single-ion conductors and enhance interfacial stability in SSLMBs.
• Material design, structural regulation, and interface engineering are crucial for optimizing COF-based SSE performance.

Conclusions:

• COF-based SSEs represent a promising avenue for developing high-performance and safer SSLMBs.
• Future research should focus on enhancing ionic conductivity, developing scalable green synthesis methods, and understanding structure-performance relationships.
• Integrated multi-functional design of COFs is essential for realizing advanced SSLMB applications.