Charge-mass transfer optimization via interfacial engineering: Advancing covalent organic frameworks toward...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) show promise for lithium-ion battery anodes due to tunable structures and high theoretical capacities.
• Existing COF anode materials face challenges like low electrical conductivity, structural instability, and poor active site utilization.
• Interfacial engineering is explored to overcome these limitations in COF-based energy storage.

Purpose of the Study:

• To address limitations of COFs as lithium-ion battery anodes through interfacial engineering.
• To investigate the charge transport mechanisms and lithium storage behavior in engineered COFs.
• To develop a high-performance COF-based anode material with enhanced conductivity and stability.

Main Methods:

• In-situ growth of dioxane-linked COF (DOL-COF) nanosheets on reduced graphene oxide (rGO) scaffolds via π-π interactions.
• Electrochemical analysis to evaluate charge-mass transport kinetics and lithium storage mechanisms.
• Theoretical calculations to elucidate charge transport characteristics and lithium storage pathways (Faradaic, pseudocapacitive, non-Faradaic).

Main Results:

• The DOL-CRG-60 nanocomposite achieved high reversible capacities (1289 mAh g^-1 at 0.1 A g^-1, 291 mAh g^-1 at 5.0 A g^-1) and excellent cycling stability (94.5% retention after 3000 cycles).
• Demonstrated an effective specific capacity of 1425 mAh g^-1 with 84.5% utilization of Faradaic active sites.
• Interfacial engineering significantly improved electronic conductivity, ion/electron transport, and active-site accessibility.

Conclusions:

• Strategic interfacial engineering of DOL-COF on rGO scaffolds effectively enhances lithium-ion battery anode performance.
• Understanding the tripartite lithium storage mechanism guided optimization for improved charge-mass transport.
• This approach offers a viable pathway for developing high-performance organic electrode materials for energy storage applications.