TiP₂O₇ and Expanded Graphite Nanocomposite as Anode Material for Aqueous Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Development of advanced anode materials is crucial for improving aqueous lithium-ion battery performance.
• Existing anode materials often face challenges with stability and energy density in aqueous electrolytes.

Purpose of the Study:

• To synthesize and characterize a novel titanium pyrophosphate/expanded graphite (TiP2O7/EG) nanocomposite.
• To evaluate the electrochemical performance of the TiP2O7/EG nanocomposite as an anode material for aqueous lithium-ion batteries.

Main Methods:

• Facile sol-gel synthesis method employed for TiP2O7/EG nanocomposite preparation.
• In situ encapsulation of TiP2O7 nanoparticles within the expanded graphite structure.
• Electrochemical testing in aqueous electrolytes, including cyclic voltammetry and galvanostatic cycling.

Main Results:

• The TiP2O7/EG electrode demonstrated a reversible capacity of 66 mAh g-1 at 0.1 A g-1 with stable operation before hydrogen evolution.
• Excellent cycling stability was observed, retaining 75% capacity after 1000 cycles at 0.5 A g-1.
• A full cell (TiP2O7/EG anode, LiMn2O4 cathode) achieved a specific energy of 60 Wh kg-1 at 1.4 V, with good rate capability and long-term cycling.

Conclusions:

• The TiP2O7/EG nanocomposite is a promising advanced anode material for high-performance aqueous lithium-ion batteries.
• The integration with expanded graphite enhances conductivity and stability, leading to superior electrochemical properties.
• This material offers a viable pathway for developing safer and more sustainable energy storage solutions.