Cation/Anion Cointerference Strategy: Boosting the Na-Storage Performance of a Pitch-Derived Carbon Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Pitch is an abundant, cost-effective carbon precursor.
• Soft carbon derived from pitch has limitations for sodium-ion (Na-ion) storage due to its graphitized structure and narrow interlayer spacing.
• Developing efficient carbon anodes is crucial for practical sodium-ion batteries.

Purpose of the Study:

• To engineer pitch-derived carbon with enhanced Na-ion storage properties.
• To convert soft carbon into hard carbon using a novel cointerference approach.
• To investigate the synergistic effect of microcrystalline order and pore architecture on Na-ion storage.

Main Methods:

• A cation/anion cointerference method using zinc acetate was employed.
• Controlled transformation of pitch-derived carbon from soft to hard carbon was achieved.
• Characterization of the modified carbon's structure, including microcrystalline order and pore architecture, was performed.

Main Results:

• The modified pitch-derived carbon (optimal sample) showed abundant closed pores and an increased pseudographitic phase.
• Na-ion storage capacity significantly improved from 87.7 mAh g^-1 to 262.6 mAh g^-1.
• An initial Coulombic efficiency of 86.5% was achieved.
• A Na-ion full cell demonstrated a reversible capacity of 339.8 mAh g^-1 and an energy density of 263.1 Wh kg^-1.

Conclusions:

• The cation/anion cointerference approach effectively transforms pitch-derived carbon into a high-performance anode material for Na-ion batteries.
• The synergistic interplay between microcrystalline structure and closed pores is key for enhanced Na-ion storage.
• This work presents a novel strategy for designing efficient carbon anodes for practical sodium-ion battery applications.