Organic batteries based on redox-active covalent organic frameworks: from molecular design to electrode optimisation

Electroactive organic materials have received much attention as alternative electrodes for metal-ion batteries due to their tuneable electrochemical properties, high theoretical capacity, resources availability, and environmental friendliness. In particular, redox-active covalent organic frameworks (COFs) have recently emerged as promising electrodes due to their structural versatility, insolubility in electrolyte, and modulable porosity. In this Feature article, we review some recent strategies to improve the energy density, power density and cycling stability of COF-based electrodes from the perspective of molecular design and electrode optimisation. Some other aspects such as scalability and recycling are also discussed. Finally, the main challenges to improve their performance and future prospects for COF organic batteries are highlighted.