Study of VDF/TrFE/CTFE terpolymers for high pulsed capacitor with high energy density and low energy loss

A study of modified PVDF polymers, which contained vinylidene difluoride(VDF), trifluoroethylene (TrFE), and chlorotrifluoroethylene (CTFE) units, was conducted for high pulsed capacitor with high energy density and low energy loss. Borane/oxygen-mediated control radical polymerization was employed to obtain high quality terpolymers, in a homogeneous acetonitrile solution at ambient temperature. The relatively sharp melting peak in all co and terpolymers implied a relatively uniform molecular structure and morphology. The charging-discharging cycles were applied to 100 MV/m and then increasing 50 MV/m intervals until reaching the breakdown electric field. The VDF/TrFE/CTFE terpolymer reduced the breakdown electric field to 350 MV/m and enlarged the polarization-depolarization hysteresis curves with higher energy loss and remnant polarization. The energy loss increased after 200 MV/m, indicating that all the energy charged was lost after 200 MV/m.