Sulfur-Driven Structural Reinforcement for Long-Life Zn-Ion Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-performance cathode materials are essential for advancing aqueous zinc-ion batteries (ZIBs).
• Challenges include enhancing stability and charge transport kinetics while suppressing material degradation.

Purpose of the Study:

• To develop a novel cathode material for ZIBs using sulfur-doped vanadium dioxide (S-VO2).
• To investigate the effects of sulfur incorporation on electronic structure, vanadium dissolution, and electrochemical performance.

Main Methods:

• Synthesis of S-VO2 cathode material.
• Electrochemical testing including specific capacity, cycling stability, and rate capability.
• Material characterization using ex situ XRD, in situ Raman, XPS, XANES, and EXAFS.

Main Results:

• S-VO2 cathode delivered a high specific capacity of 386.3 mA h g-1 at 0.1 A g-1.
• Excellent long-term cycling stability with 79.6% capacity retention after 1600 cycles at 2.0 A g-1 and 80.3% after 6000 cycles at 10.0 A g-1.
• Sulfur doping induced oxygen vacancies, enhanced conductivity, strengthened V-O bonds, and stabilized vanadium's local coordination environment.

Conclusions:

• Sulfur doping is an effective strategy to improve the performance and stability of VO2-based cathodes for ZIBs.
• The synergistic effect of sulfur doping and oxygen defects optimizes cathode material design for next-generation AZIBs.
• S-VO2 offers a promising pathway towards high-performance and reliable aqueous zinc-ion battery systems.