Stable Na⁺ Ion Storage via Dual Active Sites Utilization in Covalent Organic Framework‐Carbon Nanotube Composite

Feb 5, 2025ChemSusChem

Stable Sodium Ion Storage Using Two Types of Active Sites in a Organic Framework-Carbon Nanotube Material

AI simplified

Innovation in Energy on OpenScience ↗PubMed ↗DOI ↗

Abstract

The COF@CNT-50 composite demonstrates a reversible sodium-ion storage capacity of 164.3 mAh/g at 25 mA/g.

Redox-active covalent organic frameworks (COFs) with metal binding sites are being explored for eco-friendly energy storage solutions.
The synthesis involves creating a triazine-based polyimide COF with dual redox-active sites, enhancing its functionality.
Covalent linking with amino-functionalized multiwalled carbon nanotubes (CNTs) improves the electronic conductivity and stability of the composites.
The growth of COF layers on CNTs enhances sodium-ion diffusion kinetics during the charging and discharging processes.
Ex situ analysis indicates the significance of dual active sites in the sodium-ion diffusion mechanism.
Density functional theory (DFT) calculations provide insights into sodium binding sites and their influence on storage capacity.

AI simplified

Redox-active covalent organic frameworks (COFs) with metal binding sites are increasingly recognized for developing cost-effective, eco-friendly organic electrodes in rechargeable energy storage devices. Here, we report a microwave-assisted synthesis and characterization of a triazine-based polyimide COF that features dual redox-active sites (-C=O from pyromellitic and -C=N- from triazine) and COF@CNT nanocomposites (COF@CNT-X, where X=10, 30, and 50 wt % of NH-MWCNT) formed through covalent linking with amino-functionalized multiwalled carbon nanotubes. These composites are evaluated as cathode materials for the sodium-ion batteries (SIBs). The amine functionalization renders the covalent bond between COF and CNT, improving electronic conductivity, structural rigidity, and long-term stability. The interfacial growth of COF layers on CNTs increases accessible redox-active sites, enhancing sodium diffusion kinetics during sodiation/desodiation. The COF@CNT-50 composite exhibits outstanding Naion storage performance (reversible capacity of 164.3 mAh gat 25 mA g) and excellent stability over 1000 cycles at ambient temperature. At elevated temperature (65 °C), it also maintains good capacity and cycle stability. Ex situ XPS analysis confirms the importance of dual active sites in the Nadiffusion mechanism. Density functional theory (DFT) calculations reveal insights into Nabinding sites and corresponding binding energies into COF structure, elucidating the experimental storage capacity and voltage profile. 2 + -1 -1 + +

Full Text

Full text is available at the source.

View full text ↗

Stable Na⁺ Ion Storage via Dual Active Sites Utilization in Covalent Organic Framework‐Carbon Nanotube Composite

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the innovation in energy brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the innovation in energy brief