Abstract In recent years a strong interest has been devoted to supercapacitor technology. However, while great attention has been paid to electrodes, electrolytes and gel polymer electrolytes, only few reports have been dedicated to macroporous separators. Hereby, in the frame of project SEPBATT/DURAMAT, macroporous poly(vinylidene fluoride) (PVdF) based separators were prepared by phase inversion technique for applications of supercapacitors. Their mechanical properties are relatively lower than those of commercial membranes nevertheless such membranes exhibit good thermal stability. Whereas commercial cellulose based separators filled with tetraethyl ammonium tetrafluoroborate + CH3CN electrolyte show 10 mS/cm (at 25°C), our PVdF macroporous separators exhibit significantly higher conductivity (18 mS/cm) under the same conditions. This study was completed with application of reinforcement techniques (addition of composites, crosslinking by irradiation) on to previously prepared membranes in order to increase their mechanical strength. Reinforced membranes showed good high mechanical strength whereas the ionic conductivity is almost maintained (15mS/cm).
Novel Macroporous PVdF based separators for supercapacitors