Coal-Derived Graphene/MoS₂ Heterostructure Electrodes for Li-Ion Batteries: Experiment and Simulation Study

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing high-performance anode materials is crucial for advancing lithium-ion battery technology.
• Molybdenum disulfide (MoS₂) shows promise but faces challenges in capacity and rate capability.
• Graphene integration can enhance the electrochemical properties of MoS₂.

Purpose of the Study:

• To synthesize and characterize a novel coal-derived graphene-intercalated MoS₂ heterostructure.
• To evaluate its potential as an anode material for lithium-ion storage.
• To investigate the structural and electrochemical enhancements provided by graphene intercalation.

Main Methods:

• Facile in situ hydrothermal synthesis followed by high-temperature calcination.
• Characterization using XRD, FE-SEM, HR-TEM, HR-Raman, and TOC analysis.
• Electrochemical performance testing (discharge capacity, cycling stability, rate capability) and first-principles simulations.

Main Results:

• Successfully prepared a MoS₂/graphene (MoS₂-G) heterostructure with a 3D flower-like morphology.
• The MoS₂-09% G anode achieved a high initial discharge capacity of ~929 mAh/g.
• Maintained ~813 mAh/g after 150 cycles and demonstrated excellent rate capability (~579 mAh/g at 2000 mA/g).
• First-principles calculations confirmed reduced Li-ion diffusion barriers in the heterostructure.

Conclusions:

• The coal-derived graphene-intercalated MoS₂ heterostructure offers enhanced electrode kinetics and Li-ion storage performance.
• The unique structure and graphene intercalation significantly improve electrochemical properties compared to bare MoS₂.
• This novel heterostructure presents a promising anode material for next-generation high-performance lithium-ion batteries.