Stable quasi-solid-state lithium-organic battery based on composite gel polymer electrolyte and compatible organic...

Area of Science:

• Materials Science
• Electrochemistry
• Organic Chemistry

Background:

• Organic small-molecule electrode materials for high-performance batteries suffer from high solubility in liquid electrolytes.
• Quasi-solid-state lithium organic batteries (LOBs) offer a solution using gel polymer electrolytes, improving safety and inhibiting active material dissolution.
• Developing stable and high-performance organic electrode materials is crucial for next-generation energy storage.

Purpose of the Study:

• To synthesize and evaluate novel hexaazatriphenylene (HATN)-based organic cathode materials for quasi-solid-state LOBs.
• To investigate the impact of functional groups on electrochemical performance and interfacial compatibility.
• To optimize the gel polymer electrolyte composition for enhanced battery performance.

Main Methods:

• Synthesis of two HATN-based organic cathode materials: HATNA-6OCH3 and HATNA-6OH.
• Construction of quasi-solid-state LOBs using polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) based gel polymer electrolytes.
• Electrochemical characterization, including specific capacity and cycling stability measurements.
• Density functional theory (DFT) calculations and spectral characterizations to elucidate the lithium-ion storage mechanism.

Main Results:

• HATNA-6OH demonstrated enhanced electrochemical properties compared to HATNA-6OCH3 due to improved interfacial compatibility via its hydroxyl group.
• The quasi-solid-state LOB using HATNA-6OH and a succinonitrile (SN)-modified gel polymer electrolyte (GPE-0.4SN) achieved a high specific capacity of 153.3 mAh g-1 at 50 mA g-1.
• Excellent reversible capacity of 88 mAh g-1 was maintained after 100 cycles at 200 mA g-1, indicating good stability.
• DFT and spectral analyses provided insights into the electrochemical properties and lithium-ion storage mechanism.

Conclusions:

• HATNA-6OH is a promising organic cathode material for quasi-solid-state LOBs, offering improved stability and electrochemical performance.
• The use of gel polymer electrolytes, particularly when modified with plasticizers like SN, is effective in overcoming the solubility issues of organic electrode materials.
• This study provides a foundation for designing advanced organic electrode materials and electrolytes for safer and more efficient energy storage devices.