A high-temperature stable composite polyurethane separator coated Al2O3 particles for lithium ion battery

PUC separator filled with ceramic (Al2O3) materials were prepared by electrostatic spinning technique in polyurethane (PU) with three-dimensional nanofiber structure, which has a smaller average pore size (1.088 mu m), higher porosity (63.7%), higher liquid absorption (371%) and higher ionic conductivity (6.5 x 10-4 S cm-1) compared with commercial polypropylene (Celgard, PP) separators. The electrode composed of a separator and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material has a low interfacial resistance and good rate performance (139.5 mAh g-1) at 5C, furthermore, it keeps 82.7% discharge capacity after 200 cycles at 1C, which is slightly higher than that of Celgard as separator (78.8%), it shows that PUC separator is conducive to the infiltration of electrolyte, and has no obvious effect on circulation performance.

Automated summary

PUC separator filled with ceramic materials was prepared using electrostatic spinning technique. It showed superior properties compared to commercial polypropylene separator, including smaller pore size, higher porosity, higher liquid absorption, and higher ionic conductivity. The electrode composed of PUC separator and NCM811 cathode material exhibited low interfacial resistance and good rate performance. It maintained a high discharge capacity even after 200 cycles.