Fast solid-solid redox kinetics of aqueous ZnS batteries realized by selenium-linked electron transfer bridge

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous ZnS batteries are promising for safe, sustainable energy storage.
• Kinetic limitations due to poor electron transfer and catalyst affinity hinder ZnS battery performance.

Purpose of the Study:

• To enhance redox kinetics in aqueous ZnS batteries.
• To develop a novel host material for improved sulfur cathode performance.

Main Methods:

• Designed selenium-doped hollow carbon spheres (Se-HCS) to form a CSeS electron bridge.
• Investigated the effect of the CSeS bridge on electron transfer and catalyst interaction.
• Fabricated and tested aqueous ZnS battery prototypes.

Main Results:

• The CSeS electron bridge facilitated rapid solid-solid redox kinetics.
• Achieved high reversible capacity (1652 mAh g⁻¹ at 0.1 A g⁻¹).
• Demonstrated low voltage polarization (0.49 V at 0.1 A g⁻¹) and excellent rate capability (450 mAh g⁻¹ at 6 A g⁻¹ after 500 cycles).

Conclusions:

• The CSeS electron bridge effectively overcomes kinetic limitations in conversion-type electrodes.
• Se-HCS provides a dual-functional host material for advanced metal-sulfur batteries.
• This strategy offers a new paradigm for designing high-performance host materials for energy storage.