Full-Active-Unit Molecular Design Strategy Enabling High-Capacity and Stable Quinone Organic Cathodes for Lithium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Organic Chemistry

Background:

• Redox-active quinones are promising organic cathode materials (OCMs) for lithium-ion batteries (LIBs).
• Challenges include rapid dissolution in electrolytes and reduced capacity due to non-active structural motifs.
• A full-active-unit molecular design strategy is proposed to overcome these limitations.

Purpose of the Study:

• To develop novel OCMs with low solubility and high specific capacity.
• To investigate a molecular design strategy connecting multiple quinone units to a core structure.
• To synthesize and evaluate new quinone-based cathode materials for LIBs.

Main Methods:

• Synthesized 2,7-bis(9,10-anthraquinonyl)pyrene-4,5,9,10-tetraone (BAPO) and 2,7-bis(9,10-phenanthraquinonyl)pyrene-4,5,9,10-tetraone (BPPO).
• Characterized materials for solubility and electrochemical performance.
• Conducted long-term cycling stability tests on LIBs using the synthesized OCMs.

Main Results:

• Both BAPO and BPPO exhibited low solubility in organic electrolytes.
• The BAPO cathode delivered a high capacity of 317.5 mAh g^{- 1} at 0.2 C.
• Exceptional cycling stability was observed, with 70.2% capacity retention after 9000 cycles at 5 C.

Conclusions:

• The full-active-unit molecular design strategy effectively enhances OCM performance.
• This approach enables simultaneous achievement of high capacity and long cycle life in LIBs.
• Developed quinone cathode materials offer a promising alternative for next-generation energy storage solutions.