Covalent organic framework membranes for energy storage and conversion

Covalent organic frameworks (COFs) are a class of porous crystalline materials based on reticular and dynamic covalent chemistry. Flexible molecular design strategies, tunable porosity, modifiable frameworks, and atomically precise structures have made them powerful platforms for developing advanced devices in energy storage and conversion. In particular, the emergence of COF membranes has dramatically expanded the application scenarios for insoluble and un-processable COF powders and opened new doors for their utilization in the field of energy storage and conversion. In this process, exciting research activities have emerged, ranging from synthesis methods to energy-related applications of COF membranes. Therefore, in this critical review, current research progress on the utilization of COF membranes for energy devices, specifically fuel cells, rechargeable batteries, supercapacitors, and photo/osmotic energy conversion, is first comprehensively reviewed in terms of the core features, design principles, synthesis methods, properties, engineering technologies and applications of COF membranes. Meanwhile, the key challenges and prospects of COF membranes in energy-related applications are also meticulously reviewed and addressed. We sincerely expect that this review can further stimulate the research enthusiasm for COF membranes in energy-related applications and offer valuable guidance for the design and application strategies of advanced COF membranes with a focus on energy devices.