Multiple Accessible Redox-Active Sites in a Robust Covalent Organic Framework for High-Performance Potassium Storage
Xue-Ling Chen1, Mo Xie1, Ze-Lin Zheng1
1College of Chemistry and Materials Science, Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and Applications, Jinan University, Guangzhou 510632, China.
Journal of the American Chemical Society
|February 16, 2023
Summary
This study introduces a novel porous covalent organic framework (COF) for high-performance potassium-ion battery (KIB) anodes. The new material offers excellent capacity, rate capability, and cycling stability for advanced energy storage.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Covalent organic frameworks (COFs) show promise for potassium-ion battery (KIB) anodes due to their porous structure and stability.
- Current COF-based KIB anodes face limitations in reversible capacity and rate capability.
Purpose of the Study:
- To design and investigate a novel porous bulk COF with enhanced potassium storage performance.
- To identify the key structural and electronic features responsible for high-performance potassium storage in COFs.
Main Methods:
- Theoretical calculations were employed to identify promising COF structures.
- Synthesis and characterization of the designed porous bulk COF.
- Electrochemical testing of the COF as a KIB anode.
Main Results:
- The designed porous COF exhibits a high reversible capacity of 423 mAh g⁻¹ at 0.1 C.
- Excellent rate capability was achieved, with 185 mAh g⁻¹ at 10 C.
- The material demonstrated robust cycling stability and minimal volumetric change.
Conclusions:
- The porous COF, featuring pyrazines and carbonyls, provides multiple accessible redox sites for efficient potassium storage.
- A surface-dominated storage mechanism and stable electrode structure contribute to superior KIB anode performance.
- The study confirms the active sites are C═O, C═N, and cation-π interactions, paving the way for advanced COF design.
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