Side-Chain Modulation in Diketopyrrolopyrrole-Based Covalent Organic Frameworks for Fast and Durable Lithium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Organic Chemistry

Background:

• High-performance anode materials are crucial for advanced rechargeable batteries.
• Covalent organic frameworks (COFs) offer tunable structures for energy storage.

Purpose of the Study:

• To develop novel pyrene-linked diketopyrrolopyrrole (DKP)-based COFs with enhanced electrochemical performance.
• To investigate the effect of side-chain engineering on ion storage properties.

Main Methods:

• Systematic synthesis of DKP-based COFs with methyl and ether functionalities.
• Electrochemical testing for lithium and sodium ion storage.
• Density functional theory (DFT) and nudged elastic band (NEB) calculations.

Main Results:

• Ether-modified Py-DKPOMe COF achieved 265 mA h g^{- 1} initial capacity and maintained 100 mA h g^{- 1} at 20C.
• Demonstrated ultrafast charging (80% SoC in 61.7 s) and excellent cycling stability.
• Showcased promising sodium-ion storage (138 mA h g^{- 1}) and high Li⁺ diffusion coefficient (7.12 × 10^-10 cm² s^-1).

Conclusions:

• Molecular-level design of COFs enables fast and durable organic electrodes.
• Ether-functionalized COFs are promising candidates for high-performance battery anodes.
• Py-DKPOMe COF demonstrates practical applicability in full-cell configurations.