Constructing Charge Transfer Pathways via π-Conjugation Modulation for Long-Cycling Mg-S Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Rechargeable magnesium-sulfur (Mg-S) batteries offer safe, abundant energy storage.
• Sluggish polysulfide conversion limits Mg-S battery performance, hindering practical application.

Purpose of the Study:

• To develop an electrocatalyst to accelerate polysulfide conversion in Mg-S batteries.
• To enhance the charge transfer and MgS2 reduction kinetics for improved battery performance.

Main Methods:

• Utilized cuprous tetrahydroxyquinone (Cu-THQ) as an electrocatalyst on a polypropylene interlayer.
• Investigated electronic modulation via restricted π-delocalization and enhanced electron donation to Cu centers.
• Analyzed charge-transfer pathways and Cu-S orbital hybridization.

Main Results:

• Cu-THQ interlayer facilitated robust anchoring and accelerated reduction of MgS2 intermediates.
• Mg-S batteries achieved a high reversible capacity of 470 mAh g⁻¹ after 2000 cycles at 8.36 A g⁻¹.
• Stable cycling performance was demonstrated at -20 °C.

Conclusions:

• A π-conjugation-driven approach effectively accelerates polysulfide conversion in Mg-S batteries.
• The Cu-THQ interlayer promotes the development of long-life, high-performance Mg-S batteries.
• This strategy holds promise for advancing next-generation energy storage systems.