An Ion-Channel-Restructured Zwitterionic Covalent Organic Framework Solid Electrolyte for All-Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Organic solid electrolytes are crucial for safe, high-energy-density all-solid-state lithium metal batteries.
• Challenges exist in promoting ion pair dissociation and transport within organic solid electrolytes.

Purpose of the Study:

• To develop a new strategy for enhancing lithium-ion dissociation and transport in organic solid electrolytes.
• To create a zwitterionic covalent organic framework (Zwitt-COF) for advanced battery applications.

Main Methods:

• Synthesis of a zwitterionic covalent organic framework (Zwitt-COF) with defined chemical and pore structures.
• Characterization of the Zwitt-COF as a solid electrolyte.
• Electrochemical testing of battery performance.
• Theoretical simulations to understand ion transport mechanisms.

Main Results:

• The Zwitt-COF solid electrolyte achieved high room-temperature ionic conductivity (1.65 × 10⁻⁴ S cm⁻¹).
• It demonstrated a wide electrochemical stability window and stable lithium plating/stripping.
• The material effectively inhibited lithium dendrite and dead lithium formation, leading to 99% capacity retention and 98% Coulombic efficiency.

Conclusions:

• Zwitterionic groups in COFs facilitate ion pair dissociation and Li+ transport.
• The Zwitt-COF strategy offers a promising alternative for constructing advanced solid-state lithium batteries.
• This approach can be extended to develop various solid-state battery technologies.