Sodium-Based Dual-Ion Battery Based on the Organic Anode and Ionic Liquid Electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-ion batteries (SIBs) offer a sustainable alternative to lithium-ion batteries.
• Dual-ion batteries (DIBs) combine advantages of different battery chemistries for enhanced performance.
• Organic electrode materials are being explored for sustainable and high-performance batteries.

Purpose of the Study:

• To develop a superior sodium-based dual-ion battery (Na-DIB) by integrating organic anode materials with ionic liquid electrolytes.
• To evaluate the electrochemical performance, including specific discharge capacity, capacity retention, and rate capability.
• To investigate the self-discharge characteristics of the developed Na-DIB system.

Main Methods:

• Fabrication of a Na-DIB system utilizing a PTCDA organic anode and an ionic liquid (IL) electrolyte.
• Electrochemical testing including galvanostatic cycling at various C-rates (0.5C, 2C, 20C).
• Assessment of capacity retention, coulombic efficiency (CE), and self-discharge rate over extended cycling.

Main Results:

• The Na-DIB achieved a high specific discharge capacity of 177 mAh g^-1 at 0.5C.
• Excellent capacity retention exceeding 100% at 2C after 200 cycles was observed.
• Remarkable performance at 20C with 60 mAh g^-1 capacity, near 100% CE, and 94% retention after 1000 cycles.
• An exceptionally low self-discharge rate of 0.18% h^-1 was recorded.

Conclusions:

• The developed PTCDA-based Na-DIB with an IL electrolyte demonstrates superior electrochemical performance.
• This Na-DIB system exhibits excellent rate capability, cycling stability, and low self-discharge.
• The findings suggest this Na-DIB is a highly promising candidate for large-scale energy storage applications.