Interfacial Coupling toward Bismuth Sulfide/MXene Heterostructures Empowering Reversible Magnesium Storage

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Bismuth-based compounds are promising anodes for rechargeable magnesium batteries (rMBs) due to their conversion-alloying reaction mechanisms.
• Challenges include sluggish kinetics, poor reversibility, and structural instability, hindering practical application.

Purpose of the Study:

• To develop enhanced anode materials for rMBs with improved magnesium storage performance.
• To investigate the structure-property relationships in novel bismuth-based heterostructures.

Main Methods:

• Synthesis of monodispersed Bi₂S₃ anchored on MXene via self-assembly.
• Characterization of interfacial bonding (Ti-S, Ti-O-Bi).
• Evaluation of electrochemical performance for magnesium storage.
• Computational studies using Density Functional Theory (DFT).
• Ex situ investigations to reveal reaction mechanisms.

Main Results:

• Bi₂S₃/MXene heterostructures exhibit strong interfacial bonding, good electrical conductivity, and high mechanical strength.
• Enhanced magnesium storage capability with improved kinetics and reversibility.
• DFT calculations and kinetic analyses confirm favorable charge transfer and low ion diffusion barriers.
• A stepwise insertion-conversion-alloying reaction mechanism was identified.

Conclusions:

• The Bi₂S₃/MXene heterostructures demonstrate superior performance for rMBs.
• Interfacial coupling engineering is crucial for designing high-performance energy storage materials.
• This approach offers significant inspiration for developing advanced multicompositional hybrids for energy storage applications.