Pyroelectric conversion cycle of vinylidene fluoride-trifluoroethylene copolymer

Copolymers of vinylidene fluoride-trifluoroethylene P(VDF-TrFE) exhibit large piezoelectric and pyroelectric effects. In addition to the most common application of the pyroelectric effect (radiant detection) it is possible to convert heat directly into electrical energy by pyroelectric conversion. This study reports the first pyroelectric conversion cycle to be measured for the copolymer P(VDF-TrFE). It is found that standard isothermal D-E hysteresis loop measurements are not necessarily accurate predictors of pyroelectric conversion performance for this material. Conduction effects are found to obscure the observation of conversion cycles in most cases for the presently available materials. In spite of these difficulties, a conversion cycle was measured whose output electric energy density was 30 mJ/cm³. The output density is 15 times larger than any other polymer previously measured .