High Voltage Flexible Sodium-Ion Battery Cathode Materials Based on 1D Covalent Organic Framework

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Covalent organic frameworks (COFs) are promising for sodium-ion batteries (SIBs) due to their porous structure.
• Conventional 2D and 3D COFs often need post-processing for improved electrochemical performance.

Purpose of the Study:

• To synthesize and evaluate a 1D imine-linked COF (TP-PDA) as an electrode material for SIBs.
• To investigate the electrochemical performance and stability of TP-PDA in SIBs.

Main Methods:

• One-step Schiff base reaction for synthesizing the 1D COF, TP-PDA.
• Electrochemical testing of TP-PDA in SIB half-cells and full-cells with hard carbon anodes.
• Assessment of cycling stability, capacity retention, and performance under bending conditions.

Main Results:

• TP-PDA exhibits a fully conjugated and porous structure facilitating efficient sodium-ion transport.
• The material shows stable cycling performance with high average discharge potential (3.1 V) and capacity retention (>90% after 1800 cycles).
• Full cells demonstrate remarkable stability (122 mAh g^-1 after 10,000 cycles) and flexibility.

Conclusions:

• The synthesized 1D COF (TP-PDA) is a highly stable and efficient electrode material for SIBs.
• TP-PDA's properties make it suitable for flexible and wearable energy storage applications.