Relation between microscopic structure and macroscopic properties in polyacrylonitrile-based lithium-ion polymer gel...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Polymer gel electrolytes (PGEs) offer high ionic conductivity with improved safety.
• The relationship between PGE microscopic structure and macroscopic properties is not fully understood.
• Investigating polymer-electrolyte interactions is key to optimizing PGE performance.

Purpose of the Study:

• To elucidate the microscopic and macroscopic changes in a polyacrylonitrile (PAN)-based PGE at varying polymer concentrations.
• To understand the role of polymer concentration in governing polymer-ion and polymer-polymer interactions.
• To correlate structural transitions with observed electrochemical properties.

Main Methods:

• Preparation of PGEs with a lithium-carbonate electrolyte and polyacrylonitrile (PAN) at different concentrations.
• Microscopic and macroscopic characterization of the PGEs.
• Analysis of polymer-ion and polymer-polymer interactions as a function of PAN concentration.

Main Results:

• PGE structure transitions from a polymer solution to a gel with increasing PAN concentration.
• Polymer-ion and polymer-polymer interactions are concentration-dependent.
• Electrolyte conductivity is minimally affected by polymer addition, even at high concentrations.

Conclusions:

• Polymer concentration is a critical factor in determining PGE structure and properties.
• PGEs transition from solutions to gels with distinct polymer matrices and dispersed electrolytes.
• Understanding these concentration-dependent interactions is vital for designing advanced PGEs.