Polyaniline-grafted hydrolysed polyethylene as a dual functional interlayer/separator for high-performance Li-S@C...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulphur batteries (LSBs) offer high theoretical energy density but suffer from the polysulphide shuttle effect.
• Soluble polysulphide intermediates migrate between electrodes, leading to capacity decay and poor cycle life.
• Effective strategies are needed to confine polysulphides and improve LSB performance.

Purpose of the Study:

• To develop a dual-functional interlayer/separator to mitigate polysulphide migration in LSBs.
• To enhance the electrochemical performance and stability of lithium-sulphur batteries.
• To create a S@C core-shell structure for improved sulphur cathode utilization.

Main Methods:

• A modified hydrolysed polyethylene-polyaniline composite was synthesized for use as an interlayer/separator.
• A solvent-free coating process was employed to encapsulate sulphur with carbon nanoparticles, forming a S@C core-shell structure.
• Electrochemical performance was evaluated using techniques such as cyclic voltammetry and galvanostatic charge-discharge cycling.

Main Results:

• The polyethylene-polyaniline interlayer effectively reduced the migration of soluble polysulphide intermediates.
• The S@C core-shell structure exhibited high electrical conductivity and minimized volume changes during cycling.
• The modified LSBs demonstrated significantly improved high-performance characteristics and cycle stability.

Conclusions:

• The dual-functional interlayer/separator and S@C cathode structure are highly effective in suppressing the polysulphide shuttle effect.
• This approach provides a promising strategy for developing high-performance and stable lithium-sulphur batteries.
• The chemical interaction between polyaniline and polysulphides, coupled with the robust S@C cathode, enhances overall battery efficiency.