Scalable Fabrication of Ionic‐Conductive Covalent Organic Framework Fibers for Capturing of Sustainable Osmotic Energy

High‐performance covalent organic framework (COF) fibers are demanded for an efficient capturing of blue osmotic power because of their excellent durability, simple integration, and large scalability. However, the scalable production of COF fibers is still very challenging due to the poor solubility and fragile structure of COFs. Herein, for the first time, it is reported that COF dispersions can be continuously processed into macroscopic, meter‐long, and pure COF fibers using a wet spinning approach. The two presented COF fibers can be directly used for capturing of osmotic energy, avoiding the production of composite materials that require other additives and face challenges such as phase separation and environmental issues induced by the additives. A COF fiber exhibits power densities of 70.2 and 185.3 W m−2 at 50‐fold and 500‐fold salt gradients, respectively. These values outperform those of most reported systems, which indicate the high potential of COF fibers for capturing of blue osmotic energy. 1D covalent organic framework (COF) fibers obtained by processing of COF dispersions using a wet spinning technique: Dispersions of 2D COFs are continuously processed into flexible solid fibers on a large scale using a wet spinning approach. These COF fibers with excellent tensile properties exhibit good performance for the capture of osmotic energy as ionic conductors.