Locally Ordered Graphitized Carbon Cathodes for High-Capacity Dual-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Dual-ion batteries (DIBs) face limitations in energy density due to issues during deep charging.
• Anion intercalation in graphite is hindered by strong anion-anion repulsions and volumetric expansion.

Purpose of the Study:

• To enhance the energy density of DIBs by developing novel cathode materials.
• To overcome the limitations of anion storage in graphite-based cathodes.

Main Methods:

• Quantum mechanical modeling to understand anion intercalation mechanisms.
• Synthesis and characterization of locally ordered graphitized carbon (LOGC) cathodes.
• Fabrication and electrochemical testing of potassium-based DIBs (KDIBs) using LOGC cathodes.

Main Results:

• LOGC cathodes weaken interlaminar van der Waals interactions and buffer anion-anion repulsions.
• Disordered carbons in the LOGC structure provide additional capacitive anion storage sites.
• The proof-of-concept KDIB demonstrated a high specific capacity (232 mAh g⁻¹ at 50 mA g⁻¹) and excellent rate capability (110 mAh g⁻¹ at 2000 mA g⁻¹).

Conclusions:

• LOGC cathodes are a promising strategy for improving DIB performance.
• The developed KDIB exhibits unprecedented specific capacity and cycling stability.
• This work paves the way for next-generation high-energy-density energy storage devices.