Triboelectric nanogenerators (TENG) are appealing mechanical energy harvesting devices that could power small portable devices and detectors.[1] They can also act as self-powered sensors for mechanical displacement, chemical, acoustic sensing, and biomedical monitoring. The working principles of TENG devices are based on friction-related electrification – triboelectrification. Some of the recent works report that TENG output can be improved by using polarized ferroelectric films as the contacting layers.[2] In the present work, porous polyvinylidene fluoride (PVDF) and BaTiO3 nanocomposite films (BaTiO3 content in a range from 0 to 35 vol%) have been prepared using spin-coating and consecutive immersion-precipitation. A clear correlation between the piezoelectric response of inversely polarized ferroelectric PVDF/BaTiO3 nanocomposite films and the performance of the TENG device based on these films is demonstrated. Nanocomposite films with the optimal composition (25 vol% BaTiO3) show a 48 pC N−1 piezoelectric coefficient, considerably higher than usually reported for such composites, and in TENG mode a record-high 2.7 kV open-circuit voltage is achieved. This observation is explained by magnified electrostatic induction that is driven by the piezoelectric charges and ferroelectric properties of these films. However, our results also indicate that piezoelectric charges cannot be solely responsible for great TENG performance; thus, a “double capacitor model” has been introduced. The mechanism involves interaction between two charged ferroelectric layers during contact−separation and contacted inversely polarized layers can be considered as capacitors connected in series. Air gap formation during separation rapidly decreases the total capacitance while the potential difference increases. The induced charge redistribution in the external circuit is registered as a current. Predictions of our model also hold true when experimentally obtained charge density (6.55 nC cm−2) values are compared with ones obtained from model calculations (6.60 nC cm−2). Furthermore, findings uncover the potential for vast improvement in the field of nanogenerators for mechanical energy harvesting as a significantly better piezoelectric performance of flexible nanogenerators has been reported elsewhere. As triboelectric research continues to thrive and expand, we anticipate that our work will help the TENG community to further improve the performance of ferroelectric-based TENG devices.