Triboelectric nanogenerator (TENG) is a novel technology to harvest mechanical energy in different forms and convert it into electricity. Elucidation of the governing parameters on triboelectrification is critical to improve the power outputs of TENGs. The degree of electrification a TENG friction layer can achieve is one of the most important parameters that governs a TENG’s power output. Polyvinylidene fluoride (PVDF) is widely used as the negative friction layers in TENGs due to its ability to attract electrons. While semi-crystalline PVDF possesses several crystal polymorphs, its electroactive crystal phases (i.e.,  and  crystals) would enhance their abilities to attract electrons. In this research, non-isothermal crystallization and supercritical carbon dioxide (ScCO2) processing followed by electric poling were used to fabricate porous PVDF with high contents of electroactive crystal phases. Fourier-transform infrared spectroscopy revealed that this processing strategy increased PVDF’s electroactive phase content from 36.6% to 75.1%. Scanning electron microscopy showed that the ScCO2 processing introduced microcellular structures in PVDF, which significantly increased its surface area-to-volume ratio. This would enhance the PVDF friction layer’s degree of electrification. Furthermore, the effects of non-isothermal crystallization, ScCO2 processing, and the subsequent electric poling on the power outputs of TENGs were investigated. Experimental results revealed that the open circuit voltage and the short circuit current of TENG increased from 16.9 V and 0.50 µA to 61.0 V and 1.66 µA, respectively. As a result, the fabricated TENG was able to light up over 50 serially connected commercial LEDs. In short, this work helps to elucidate the processing-structure-property relationship of PVDF film in the context of triboelectrification and the resultant TENG’s energy harvesting performance.