Zirconia/polyethylene terephthalate ceramic fiber paper separator for high-safety lithium-ion battery

The non-woven mat has a three-dimensionally distributed fiber structure, but because the randomly dispersed structure caused the pore diameter of the separator to enlarge, this may lead to a short circuit of the battery. In this work, organic polyethylene terephthalate (PET) was combined with inorganic zirconia (ZrO2) ceramic fiber using a low-cost papermaking method. The addition of PET blocked part of the macropores of the fiber separator, enabling the separator a suitable pore size. The PET connected the nodes of the zirconia fibers to provide mechanical support. At the same time, the ZrO2-PET composite separator inherited the excellent high temperature resistance of zirconia ceramic fiber and a maintained dimensional stability after heating at 300 degrees C for 1 h, providing a strong guarantee for the safe performance of the battery. We found that when the concentration of PET was 5%, the highest electrolyte uptake (301.83%) occurred as well as electrochemical performance. In addition, the ZrO2-PET composite separator achieved an excellent cycle performance at 60 degrees C compared with the polypropylene (PP) separator.