Intermolecular Hydrogen Bonding Mediated Micropore Activation and Structure Disorder in Hard Carbon for High-Capacity...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Hard carbon (HC) is a key anode material for sodium-ion batteries (SIBs).
• Controlling HC microstructure for optimal sodium storage is challenging.
• Rational design of HC anodes is crucial for advancing SIB technology.

Purpose of the Study:

• To develop a method for microstructure regulation in hard carbon.
• To enhance the sodium storage capacity and cycling stability of hard carbon anodes.
• To investigate the role of molecular-level interactions in carbon material design.

Main Methods:

• Molecular-level integration of polymerized citric acid-oxamide and sucrose.
• Controlled carbonization process to manipulate micropores and carbon layer curvature.
• Electrochemical testing of hard carbon anodes in sodium-ion batteries.

Main Results:

• Achieved a high reversible capacity of 421.5 mAh g⁻¹ for the hard carbon anode.
• Enabled pouch cells to reach an energy density of 151.8 Wh kg⁻¹.
• Demonstrated excellent cycling stability with 95.4% capacity retention after 800 cycles.

Conclusions:

• Intermolecular hydrogen bonding in the precursor is critical for microstructure control.
• The developed hard carbon exhibits superior performance for sodium-ion batteries.
• This approach offers a new strategy for designing high-performance carbon anode materials.