2D Vertically Conductive Metal─Organic Framework Electrolytes: Will They Outperform 3D MOFs for Solid State Batteries?

Lithium-ion batteries are currently the mainstream for almost all portables, and quickly expand in electrical vehicles and grid storage applications. However, they are challenged by the poor safety regarding organic liquid electrolytes and relatively low energy density. Solid-state batteries, characterized by using solid-state electrolytes (SSEs), are recognized as the next-generation energy technology, owing to their intrinsically high safety and potentially superior energy density. However, developing SSEs is impeded by several key factors, including low ionic conductivity, interfacial issues, and high-cost in industrial scales. Recently, a novel category of SSEs, known as frameworked electrolytes (FEs), has emerged as a formidable contender for the transition to all-solid-state batteries. FEs exhibit a unique macroscopically solid-state nature and microscopically sub-nanochannels offering high ionic conductivity. In this perspective, the unique lithium-ion transport mechanisms within FEs are explored and 2D vertically conductive metal-organic framework (MOF) is proposed as an even more promising FE candidate. The abundant active sites in the 1D sub-nanochannels of 2D vertically conductive MOFs facilitate efficient ion transport, favorable interfacial compatibility, and scalable industrial applications. This perspective aims to boost the emergence of novel SSEs, promoting the realization of long-expected all-solid-state batteries and inspiring future energy storage solutions.