Modulating Graphitization and Porosity via a Cross-Linking-Oxidation and Metal-Evaporation Bifunctional Approach in...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Hard carbon is a key anode material for sodium-ion batteries (SIBs).
• Pitch is a cost-effective precursor, but direct carbonization yields suboptimal soft carbon.
• Improving hard carbon structure is crucial for enhanced sodium storage.

Purpose of the Study:

• To develop a novel method for synthesizing high-performance hard carbon from pitch for SIBs.
• To modulate pitch graphitization using zinc gluconate.
• To enhance the sodium storage properties of pitch-based carbon anodes.

Main Methods:

• Employed a cross-linking-oxidation and metal-evaporation approach using zinc gluconate.
• Carbonized pitch with zinc gluconate to create hard carbon.
• Tested the electrochemical performance of the synthesized hard carbon as an anode in SIBs.

Main Results:

• The synthesized hard carbon anode (PZ-3:3-200-1300) showed a reversible capacity of 341.2 mAh g^-1 at 20 mAg^-1.
• Achieved a high initial Coulombic efficiency (ICE) of 87.7%.
• Demonstrated excellent rate capability and cycling stability compared to pure pitch-derived carbons.

Conclusions:

• The bifunctional approach effectively synthesizes high-performance pitch-based hard carbon for SIBs.
• Zinc gluconate successfully modulates pitch graphitization for improved anode performance.
• This method offers a promising route for advanced anode materials in sodium-ion batteries.