Heat-Resistant, Robust, and Hydrophilic Separators Based on Regenerated Cellulose for Advanced Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitor (SC) separators often exhibit poor mechanical properties, limited ion transport, electrolyte wettability, and thermal stability, hindering SC development.
• Current separators face challenges in maintaining structural integrity and facilitating efficient ion movement, impacting overall device performance and safety.

Purpose of the Study:

• To design and fabricate high-performance regenerated cellulose (RC) based separators for supercapacitors.
• To address the limitations of conventional separators by enhancing mechanical strength, ion transport, and thermal stability.

Main Methods:

• Fabrication of RC separators via hydrolytic etching of inorganic CaCO3 nanoparticles from a filled RC membrane.
• Characterization of separator properties including tensile strength, thermal stability, porosity, and electrolyte uptake.
• Electrochemical testing in 1.0 m Na2SO4 electrolyte to evaluate ion transport and permeability.

Main Results:

• The developed RC separator exhibits superior tensile strength (75.83 MPa) and thermal stability (200 °C) compared to commercial polypropylene separators.
• The RC separator demonstrates significantly enhanced electrolyte uptake rate (208.5%) and 2.5x higher ion transport and permeability.
• The material maintains structural integrity even above 200 °C, indicating excellent thermal robustness.

Conclusions:

• Porous RC separators offer a promising alternative to conventional materials for supercapacitor applications.
• The unique advantages of RC separators, including superior electrolyte wettability, mechanical robustness, and high thermal stability, contribute to high-performance and safe supercapacitors.