Quinone Electrode for Long Lifespan Potassium-Ion Batteries Based on Ionic Liquid Electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Organic electrode materials offer design flexibility for potassium-ion batteries (PIBs).
• Material dissolution and electrolyte stability are key challenges in PIBs.
• Ionic liquid electrolytes (ILEs) can mitigate dissolution and enhance safety.

Purpose of the Study:

• To investigate Pillar[5]quinone (P5Q) as a novel cathode material for PIBs.
• To evaluate the electrochemical performance of P5Q using two common ionic liquid electrolytes.
• To demonstrate the potential of P5Q-based cathodes for advanced energy storage.

Main Methods:

• Electrochemical performance testing of P5Q cathodes in PIBs.
• Utilizing two different ionic liquid electrolytes (ILEs) for comparison.
• Cycling stability and rate capability assessments at various current densities.

Main Results:

• P5Q cathode achieved a reversible capacity of 232 mAh g^-1 at 0.2C in 0.3 M KFSI-PY13FSI electrolyte.
• Exceptional cycling stability demonstrated: 101 mAh g^-1 after 1000 cycles at 2.0C.
• Sustained capacity of 61 mAh g^-1 even after 5000 cycles at 2.0C.
• High energy densities of 450 Wh kg^-1 (initial) and 125 Wh kg^-1 (over 5000 cycles) were recorded.

Conclusions:

• Pillar[5]quinone (P5Q) is a promising organic cathode material for high-performance PIBs.
• Ionic liquid electrolytes are effective in stabilizing organic cathodes and enabling long cycle life.
• This work paves the way for the development of advanced organic electrodes for PIBs.