Microporous Sulfur-Carbon Materials with Extended Sodium Storage Window

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Developing high-performance anode materials is crucial for advancing sustainable energy storage solutions like sodium-ion batteries (SIBs).
• Incorporating sulfur into carbon frameworks offers a promising strategy for enhancing anode efficiency in SIBs.

Purpose of the Study:

• To introduce a novel microporous sulfur-rich carbon anode derived from a liquid sulfur-containing oligomer for SIBs.
• To investigate the influence of synthesis temperature on sodium storage mechanisms and electrode performance.

Main Methods:

• Synthesis of a microporous sulfur-rich carbon anode from a liquid sulfur-containing oligomer.
• Electrochemical characterization of the anode material in SIBs.
• In-operando small-angle X-ray scattering (SAXS) to probe structural changes during sodium storage.

Main Results:

• Sodium storage mechanism transitions from surface-controlled to diffusion-controlled with increasing synthesis temperature.
• Electrode performance is primarily dictated by microporosity and a thiophene-rich chemical environment, not interplanar spacing.
• Achieved reversible overpotential sodium storage and extended the plateau region to higher potentials.
• In-operando SAXS confirmed reversible electron density variations consistent with pore-filling storage mechanisms.

Conclusions:

• The developed sulfur-rich carbon anode demonstrates potential for high-performance SIBs.
• Microporosity and sulfur content are key factors for designing efficient anodes for sodium-ion batteries.
• This work provides a framework for creating competitive anode materials for SIBs with enhanced energy density.