An Alternative Polymer Material to PVDF Binder and Carbon Additive in Li-Ion Battery Positive Electrode

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Li-ion battery performance depends on electrode microstructure and interfaces.
• Binders are critical for electrode integrity, interconnecting components and adhering to current collectors.
• Conventional poly(vinylidenefluoride) (PVDF) binders have drawbacks like toxic solvents, low conductivity, and poor interfacial interactions.

Purpose of the Study:

• To investigate Poly(3,4-ethylenedioxythiophene):poly[(4-styrenesulfonyl) (trifluoromethylsulfonyl) imide] (PEDOT:PSSTFSI) as a dual-function binder and conductive additive.
• To replace both PVDF and carbon black in Li-ion batteries with LiFe0.4Mn0.6PO4 positive electrodes.
• To evaluate the impact of PEDOT:PSSTFSI on electrochemical performance and electrode properties.

Main Methods:

• Fabrication of Li-ion battery electrodes using PEDOT:PSSTFSI as a binder and conductive additive.
• Electrochemical testing of electrodes at various C-rates and active mass loadings.
• Analysis of electrode microstructure and ionic/electronic transport properties.

Main Results:

• PEDOT:PSSTFSI significantly enhanced electronic conductivity and lithium diffusion within the electrode compared to PVDF and carbon black.
• Improved electrochemical performance, particularly at high C-rates and high active mass loadings.
• Demonstrated excellent long-range cyclability, indicating enhanced electrode stability.

Conclusions:

• PEDOT:PSSTFSI offers a promising alternative to conventional binders in Li-ion batteries.
• This material improves key electrochemical properties, enabling higher performance and durability.
• The dual functionality reduces processing complexity and reliance on additional conductive additives.