Experimental study demonstrates enhanced thermal stability and stretch tolerance in lithium-ion battery separators, highlighting potential for flexible energy storage.
Key Points
Develop a flexible, heat-resistant separator to overcome the severe thermal shrinkage and poor stretchability of conventional lithium-ion battery separators.
Fabricated core-shell nanofibers comprising a polyimide (PI) shell and a PI/thermoplastic polyurethane (TPU) core via coaxial electrospinning.
Evaluated thermal dimensional stability at 150 °C, tensile strain properties, and electrochemical cycling performance from 25 °C to 90 °C using pristine and pre-stretched separators.
The P@PT separator exhibited 4.03% thermal shrinkage at 150 °C compared to 96.14% for commercial polyethylene separators.
Mechanical testing showed 66.6% strain tolerance at 7.6 MPa, exceeding the stretchability of conventional polyimide separators.
Electrochemical tests demonstrated superior coulombic efficiency and capacity retention at 65–90 °C compared to polyethylene, with stable performance maintained under strain history.