Integrated Design from Microstructural Engineering to Binder Optimization Enabling a Practical Carbon Anode with...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Potassium-ion batteries (PIBs) are a promising alternative to lithium-ion batteries for large-scale energy storage due to abundant potassium resources.
• Developing high-performance anode materials with high initial Coulombic efficiency (ICE) and rate capability remains a significant challenge for practical PIB applications.

Purpose of the Study:

• To engineer petroleum coke-derived anodes for high ICE and efficient potassium storage in PIBs.
• To optimize microstructures and binder selection for enhanced electrochemical performance.

Main Methods:

• Microstructural engineering of petroleum coke precursor to achieve a high carbon residue rate (89%).
• Optimization of binder selection, specifically using sodium carboxymethyl cellulose (CMC).
• Electrochemical characterization of the PC-900 anode in PIBs, including capacity, rate capability, and cycling stability tests.

Main Results:

• The PC-900 anode achieved an ultrahigh ICE of 80.5%, among the highest reported for PIB carbon anodes.
• Demonstrated high capacity (304.3 mAh g⁻¹), excellent rate capability (138.2 mAh g⁻¹ at 10C), and superior stability.
• A full cell using the PC-900 anode showed outstanding rate and cycling performance (210.7 mAh g⁻¹ at 0.5C).

Conclusions:

• Microstructural engineering and CMC binder optimization are effective strategies for enhancing PIB anode performance.
• The developed PC-900 anode exhibits significant potential for large-scale energy storage applications.
• Understanding the two-stage K⁺ storage mechanism provides insights for future anode design.