Search

Covalent organic frameworks (COFs), featuring ordered nanopores with numerous accessible redox sites, have drawn much attention as promising electrode materials for rechargeable batteries. Thus far, however, COF‐based battery electrodes have exhibited limited capacity and unsatisfactory cycling stability due to the unwanted side reactions over their large surface area. Herein, a fluorine‐rich covalent organic framework (F‐COF) as an electrode material with improved stability and performance for potassium‐ion batteries is developed. The fluorinated COF not only stabilizes intercalation kinetics of K+ ions but also reinforces its electron affinity and conductivity, improving the reversibility of bond transitions during discharge–charge cycles. As a result, F‐COF affords a high specific capacity (95 mAh g−1 at fast rates up to 5 C) and excellent cycling stability (5000 cycles with ≈99.7% capacity retention), outperforming the pristine COF‐based electrodes devoid of F atoms. Notably, the experimental capacity of F‐COF approaches its theoretical value, confirming that a large proportion of electroactive sites are being actively utilized. Altogether, this work addresses the significant role of F atoms in improving the K+‐ion storage capability of COFs and provides the rational design principles for the continued development of stable and high‐performance organic electrode materials for energy storage devices. [ABSTRACT FROM AUTHOR]

Keywords: Covalent organic frameworks; Fluorine atoms; High storage capacity; Interface stabilization; Long-term stability; Potassium-ion battery (KIBs) EN Covalent organic frameworks Fluorine atoms High storage capacity Interface stabilization Long-term stability Potassium-ion battery (KIBs) 1 1 1 07/18/23 20230708 NES 230708 B Potassium-Ion Batteries b In article number 2300442, Ji-Won Jung, Jihan Kim, Il-Doo Kim, and co-workers show that fluorinated arenes in covalent organic frameworks enhance their electrochemical activity and stabilize the electrode-electrolyte interfaces, enabling a breakthrough design for organic electrodes with significantly increased ion storage capacity and greatly improved cyclic stability. Covalent organic frameworks, Fluorine atoms, High storage capacity, Interface stabilization, Long-term stability, Potassium-ion battery (KIBs) Fluorine-Rich Covalent Organic Framework to Boost Electrochemical Kinetics and Storages of K+ Ions for Potassium-Ion Battery (Adv. [Extracted from the article]