Recent progress on metal–organic framework/polymer composite electrolytes for solid-state lithium metal batteries: ion transport regulation and interface engineering

Abstract

Solid-state lithium metal batteries (SSLMBs) offer enhanced safety and higher energy density compared to liquid electrolyte batteries, but the insufficient ionic conductivity of solid-state electrolytes (SSEs) and their poor electrode/electrolyte interface restrict their performance. In this case, metal–organic framework (MOF)/polymer composite electrolytes with high ionic conductivity and compatible interfaces offer promising solutions. Herein, approaches to enhance the ionic transport of MOF/polymer composite electrolytes and strategies to stabilize their interfaces with electrodes are systematically summarized. Firstly, the components, functions, and ion transport mechanisms of MOF/polymer composite electrolytes are reviewed. Subsequently, the strategies for boosting ion transport, including engineering unsaturated metal sites and ligands for MOFs, integrating ionic liquids (ILs) with MOFs, and in situ growth of MOFs on polymer matrices, are discussed. In addition, various interfacial engineering strategies for electrode/electrolyte interface are highlighted. Moreover, manufacturing technologies for the large-scale industrial application of SSLMBs with MOF/polymer composite electrolytes are discussed. Finally, key challenges and future directions are highlighted for further study. This review provides a comprehensive guide for the rational design of MOF/polymer composite electrolytes for advanced SSLMBs.