Effect of Composition on Polarization Hysteresis and Energy Storage Ability of P(VDF-TrFE-CFE) Relaxor Terpolymers

The temperature dependence of the dielectric permittivity and polarization hysteresis loops of P(VDF-TrFE-CFE) polymer films with different compositions are studied. Among them, the three compositions, 51.3/48.7/6.2, 59.8/40.2/7.3, and 70/30/8.1, are characterized for the first time. Relaxor behavior is confirmed for all studied samples. Increasing the CFE content results in lowering the freezing temperature and stabilizes the ergodic relaxor state. The observed double hysteresis loops are related to the field-induced transition to a ferroelectric state. The critical field corresponding to this transition varies with the composition and temperature; it becomes larger for temperatures far from the freezing temperature. The energy storage performance is evaluated from the analysis of unipolar polarization hysteresis loops. P(VDF-TrFE-CFE) 59.8/40.2/7.3 shows the largest energy density of about 5 J center dot cm(-3) (at the field of 200 MV center dot m(-1)) and a charge-discharge efficiency of 63%, which iscomparable with the best literature data for the neat terpolymers.

Automated summary

The temperature dependence of dielectric permittivity and polarization hysteresis loops of P(VDF-TrFE-CFE) polymer films with different compositions was studied, confirming relaxor behavior in all samples. Increasing CFE content lowered the freezing temperature and stabilized the ergodic relaxor state, with observed double hysteresis loops related to a field-induced transition to a ferroelectric state. Energy storage performance was evaluated, with one composition showing the largest energy density and charge-discharge efficiency comparable to the best literature data for the neat terpolymers.