▎ 摘　　要

The use of lead-based ceramics toenhance the piezoelectricityof poly(vinylidene fluoride) (PVDF) is the primary challenge towardnontoxic flexible piezoelectric devices. 0.67BiFeO(3)-0.33BaTiO(3) (BF33BT) is one of the lead-free piezoceramics with high-temperaturestability and comparable piezoelectric characteristics to existinglead-based piezoceramics. The work represents PVDF-BF33BT two-phaseand PVDF-BF33BT-graphene oxide (GO) three-phase compositeswith detailed analysis of the dielectric, ferroelectric, and piezoelectriccharacterizations. Solvent-casting followed by the hot-pressing techniqueimproves the electroactive & beta;-phase of & GE;60% in the composites.With BF33BT and GO loading, the dielectric constant and loss tangentincrease; however, there is an abrupt rise at the threshold GO concentrationof 0.08 wt %. The three-phase composite with 40 wt % BF33BT and 0.08wt % GO records a dielectric constant of 303 and a loss tangent of0.68. The harvester out of the same composition achieves a piezoelectricstrain constant of 9 pC & BULL;N-1, an open-circuitvoltage of & SIM;3.9 V, and a short-circuit current of 1.3 & mu;A.The feasibility of the harvester was tested by powering a calculatorby charging a 2.2 & mu;F capacitor after rectification. The recoverableenergy density also improves seven times, indicating that the PVDF-BF33BT-GOcomposite is preferable for piezoelectric and energy storage applications.