Engineering Bi/V/Mo-Based Multicomponent Heterostructure Electrocatalyst Toward Robust Lithium-Sulfur Batteries and...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries face challenges with sluggish reaction kinetics and the shuttle effect of lithium polysulfides (LiPSs), hindering industrialization.
• Efficient electrocatalysts are crucial for capturing LiPSs and accelerating their conversion to improve Li-S battery performance.

Purpose of the Study:

• To design and investigate a novel Bi/Bi2O3/VMoN@rGO electrocatalyst for Li-S batteries.
• To explore the synergistic effects of multilevel heterointerfaces and reduced graphene oxide (rGO) on catalytic activity and electrochemical performance.
• To understand the in situ electrochemical reconstruction mechanism and its impact on Li2S decomposition.

Main Methods:

• Synthesis of a multifunctional Bi/Bi2O3/VMoN@rGO electrocatalyst.
• Fabrication of Li-S batteries using the designed electrocatalyst in functional separators.
• Electrochemical characterization including cycling performance, rate capability, and sulfur utilization under high sulfur loading.
• In situ characterization and theoretical calculations (e.g., DFT) to elucidate the catalytic mechanism and phase evolution.

Main Results:

• The Bi/Bi2O3/VMoN@rGO electrocatalyst demonstrated excellent electrochemical performance and high sulfur utilization in Li-S batteries.
• Multilevel heterointerfaces modulated electron distribution, charge transfer, and chemical absorption, enhancing intrinsic activity.
• In situ electrochemical reconstruction led to the formation of Bi2S3 phases, reducing the Li2S decomposition energy barrier and improving performance.
• The synergistic effects of the catalyst components and rGO provided high conductivity and structural stability.

Conclusions:

• The developed Bi/Bi2O3/VMoN@rGO electrocatalyst effectively suppresses the shuttle effect and accelerates LiPS conversion in Li-S batteries.
• In situ phase evolution to Bi2S3 is a key mechanism for performance enhancement, offering new insights into sulfur electrocatalyst design.
• This work highlights the potential of self-reconstruction strategies for developing advanced energy storage materials.