TiO₂/FeCoS Heterojunction Anode for Fast-Charging Lithium-Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Optimizing anode structure is key for fast-charging lithium-ion batteries (LIBs), requiring efficient lithium-ion diffusion and high electronic conductivity.
• Insertion-type materials are crucial for LIB anodes, but often face limitations in charge/discharge rates.

Purpose of the Study:

• To engineer a novel anode material for enhanced fast-charging capabilities in LIBs.
• To improve lithium-ion diffusion kinetics and electrochemical performance through heterojunction design.

Main Methods:

• Fabrication of a TiO2/FeCoS heterojunction anode.
• Electrochemical performance testing including capacity, rate capability, and cycling stability.
• Theoretical calculations and experimental validation to understand performance mechanisms.

Main Results:

• The TiO2/FeCoS anode demonstrated a high reversible capacity of 627.7 mAh g⁻¹ at 0.1 A g⁻¹, exceeding pure TiO2 by 2.3 times.
• Achieved a remarkable capacity of 241.7 mAh g⁻¹ at a high rate of 10 A g⁻¹.
• Exhibited excellent long-term stability with over 10,000 cycles and an ultralow capacity decay of 0.002% per cycle.

Conclusions:

• The TiO2/FeCoS heterojunction effectively enhances electron/ion transport and lowers the ion diffusion energy barrier.
• Superior performance is attributed to improved Li⁺ ion adsorption and reduced diffusion barriers at the heterointerface.
• This work presents a viable strategy for accelerating electrochemical kinetics, paving the way for advanced fast-charging LIBs.