High-Capacity NH4+ Charge Storage in Covalent Organic Frameworks
Zhengnan Tian1, Vinayak S Kale2, Yizhou Wang1
1Materials Science and Engineering, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Journal of the American Chemical Society
|November 5, 2021
Summary
Covalent organic frameworks (COFs) utilize hydrogen bond chemistry for efficient ammonium ion (NH4+) storage in aqueous batteries. This novel approach overcomes limitations of inorganic materials, enabling high capacity and improved kinetics for energy storage applications.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Ammonium ions (NH4+) are promising non-metallic charge carriers for aqueous batteries.
- Inorganic host materials face challenges due to sluggish ion diffusion kinetics.
- Covalent organic frameworks (COFs) offer potential for advanced battery applications.
Purpose of the Study:
- To explore the use of hydrogen bond chemistry in COFs for NH4+ ion storage.
- To investigate the mechanism of NH4+ storage within COFs.
- To establish a relationship between ion solvation and electrochemical performance.
Main Methods:
- Synthesis and characterization of COFs for NH4+ ion storage.
- Electrochemical testing to determine capacity and kinetics.
- Theoretical simulations and materials analysis to elucidate reaction mechanisms.
Main Results:
- Achieved a high capacity of 220.4 mAh g-1 at 0.5 A g-1 using COFs.
- Revealed a universal mechanism involving hydrogen-bonded nitrogen and oxygen sites.
- Established a correlation between NH4+ solvation behavior, redox potential, and desolvation energy.
Conclusions:
- Hydrogen bond chemistry in COFs provides an effective strategy for NH4+ ion storage.
- The elucidated mechanism offers new insights for designing advanced host materials.
- This approach can guide the development of COFs for next-generation electrochemical energy storage.
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