High-performance graphene/sulphur electrodes for flexible Li-ion batteries using the low-temperature spraying method

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sulfur (S) exhibits high capacity as a cathode material for Li-S batteries but suffers from poor cycling stability due to polysulfide dissolution.
• Encapsulation strategies are effective but often require costly materials and processes.
• Developing scalable, low-cost methods for sulfur cathode fabrication is critical for practical applications.

Purpose of the Study:

• To propose and evaluate a low-temperature spraying process for fabricating graphene/sulfur (G/S) electrodes.
• To investigate the performance of G/S electrodes prepared using cost-effective materials and scalable technology.
• To demonstrate the feasibility of flexible Li-ion batteries utilizing the developed G/S electrodes.

Main Methods:

• Fabrication of G/S electrode ink using graphene flakes and micron-sized sulfur particles from low-cost powders.
• Utilizing a low-temperature spraying process for electrode deposition, avoiding high-temperature annealing.
• Assembly and testing of Li-ion batteries with the fabricated G/S electrodes, including flexible configurations.

Main Results:

• Sulfur particles were effectively hosted within highly conductive graphene flakes.
• Achieved superior cyclability with ~70% capacity retention after 250 cycles.
• Demonstrated high specific capacity (~1500 mA h g⁻¹) and good coulombic efficiency (~98%).
• Successfully fabricated flexible Li-ion batteries using the sprayed G/S electrodes.

Conclusions:

• The low-temperature spraying process offers a scalable and cost-effective method for producing high-performance G/S electrodes.
• This approach overcomes key limitations of traditional sulfur cathodes, improving stability and capacity.
• The developed technology enables the fabrication of flexible batteries, expanding potential applications in portable electronics and beyond.