Microfiber/Nanofiber/Attapulgite Multilayer Separator with a Pore-Size Gradient for High-Performance and Safe...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion batteries (LIBs) are crucial for renewable energy storage.
• Battery separator performance directly impacts LIBs' overall efficiency.
• Porous separators facilitate ion transport, essential for battery function.

Purpose of the Study:

• To fabricate a composite separator with a pore-size gradient structure for LIBs.
• To enhance the thermal stability, porosity, and electrolyte affinity of the separator.
• To evaluate the electrochemical performance of LIBs utilizing the novel composite separator.

Main Methods:

• Fabrication of a composite separator (GOP-PH-ATP) by laminating an electrospun PVDF-HFP nanofibrous membrane with attapulgite (ATP) nanoparticles onto a PP nonwoven fabric.
• Characterization of the separator's porous structure, porosity, electrolyte uptake, and thermal stability.
• Electrochemical testing of LIBs with the composite separator, including ionic conductivity, ion transference number, and cycling performance evaluation.

Main Results:

• The GOP-PH-ATP separator exhibited a unique pore-size gradient structure.
• Achieved superhigh porosity (~95%) and excellent electrolyte uptake (~760%).
• Demonstrated high ionic conductivity (2.38 mS cm⁻¹) and ion transference number (0.62).
• LIBs with the separator showed 91.2% capacity retention after 150 cycles at 1 C.

Conclusions:

• The developed composite separator with a pore-size gradient structure significantly enhances LIB performance.
• The separator's properties, including high porosity and electrolyte affinity, are key to its effectiveness.
• This composite separator shows great potential for advanced lithium-ion battery applications.