Rational Molecular Engineering of Amidonaphthoquinone Cathodes: Precise Hydrogen Bond and Size Control for...

Area of Science:

• Materials Science
• Electrochemistry
• Organic Chemistry

Background:

• Developing high-capacity, long-cycling organic cathode materials for rechargeable batteries is challenging due to solubility issues.
• Rational molecular design is key to overcoming these limitations.

Purpose of the Study:

• To synthesize and evaluate novel naphthoquinone derivatives (NQ1-NQ3) as organic cathode materials for lithium-organic batteries (LOBs).
• To investigate the impact of amide functionalities and molecular size on electrochemical performance and solubility.

Main Methods:

• Facile synthesis of three naphthoquinone derivatives (NQ1-NQ3) with tunable amide groups.
• Electrochemical performance evaluation in LOBs, including capacity, rate capability, and cycling stability.
• Analysis of structural evolution and intermolecular interactions (hydrogen bonding, π-π stacking).

Main Results:

• NQ2 and NQ3 exhibited suppressed solubility and enhanced cycling stability due to increased intermolecular interactions.
• NQ3 displayed particle pulverization during cycling, improving electrode conductivity and contact with carbon additives.
• NQ3 achieved high specific capacity (224 mAh g⁻¹ at 0.1 A g⁻¹) and good rate capability (162 mAh g⁻¹ at 2 A g⁻¹), outperforming many organic cathodes.

Conclusions:

• Molecular design strategies, including amide incorporation and size expansion, effectively suppress organic cathode dissolution.
• Synergistic effects of structural evolution and non-covalent interactions lead to high-performance LOBs.
• This study offers insights for designing soluble-free organic electrode materials for advanced energy storage.