The porosity and electrolyte uptake are important parameters
to determine the ionic conductivity and electrochemical properties
of separators. As shown inTable 1, the porosity of the SiO2/PEI-PU
membranes is 59.14%, which is higher than that of Celgard
separator (47.62%), although it is lower than that of PEI-PU
membranes (82.15%). The difference in porosity could be attributed
to the difference in the porous structure and the packing density of
relevant membranes. Furthermore, the electrolyte uptake are
82.43, 664.34 and 188.88%, respectively, for Celgard, PEI-PU and
SiO2/PEI-PU, which were in line with the porosity of relevant
membranes, implying that the electrolyte uptake is greatly