Plasticized Polymer Composite Single-Ion Conductors for Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Lithium bis(trifluoromethane) sulfonamide (TFSI) is a key electrolyte salt for lithium batteries, offering good conductivity and dissociation.
• Improving the Li(+) transference number is crucial for enhancing battery performance.
• Silica polymer composites offer improved mechanical properties compared to pure polymers like PEO.

Purpose of the Study:

• To enhance the Li(+) transference number in lithium battery electrolytes.
• To investigate the effect of grafting TFSI analogue molecules onto silica nanoparticles.
• To compare the performance of monolayer and multilayer grafted nanoparticles.

Main Methods:

• Tethering N-pentane trifluoromethane sulfonamide (C5NHTf) onto silica nanoparticle surfaces as a monolayer.
• Polymerizing trifluoromethane sulfonic aminoethyl methacrylate (TfMA) on silica nanoparticle surfaces as a multilayer.
• Analyzing lithium content and ionic conductivity of the prepared electrolytes.

Main Results:

• Monolayer grafted nanoparticles achieved a lithium content of 1.2 × 10(-3) g Li/g.
• Multilayer grafted nanoparticles exhibited a significantly higher lithium content of 2 × 10(-2) g Li/g.
• Electrolytes from multilayer grafted particles showed a steep increase in ionic conductivity with temperature, reaching 3 × 10(-5) S/cm at 80 °C.

Conclusions:

• Grafting TFSI analogue molecules onto silica nanoparticles is an effective strategy to increase lithium content and improve ionic conductivity.
• Multilayer grafting offers superior performance compared to monolayer grafting for lithium battery electrolytes.
• The developed materials show promise for advanced lithium battery applications.