Improved Performance of Multilayer Assembled Piezoelectric Nanogenerator with Electrospun Nanofiber Mats for Self-Powered Wearable Sensors

摘要: The limited throughput, sensitivity, and stability of piezoelectric nanogenerators (PENGs) have impeded their adoption in practical, long-term applications as self-powered wearable sensors. Although stacking piezoelectric layers is considered as an effective approach to improve their electrical performance, the overall enhancement does not consistently equate to the sum of individual single-layer PENG (S-PENG) performances, due to factors such as interfacial losses and coupling effects between layers. To overcome these limitations, we report on an enhanced performance multilayer piezoelectric nanogenerator (M-PENG) fabricated by alternatively stacking layers of barium titanate nanoparticles (BT NPs) and graphite nanosheets (GNS)-embedded poly (vinylidene fluoride-co-trifluoroethylene)(P (VDF-TrFE)) nanofibers (NFs) mats. The results demonstrate that the M-PENG's output open circuit voltage (Voc) gradually improved as the number of layers increased to six, ultimately achieving a Vocof 350 V, a short circuit current (Isc) of 6 µA, and a power density of 3.62 W m-2. The electrical performance of the 6L M-PENG surpassed the Voc values of single layer-PENGs and 6L M-PENG based on P10BT NFs and P0. 10GNS NFs by factors of 12.5, 15.9, 1.75, and 1.42, respectively. Furthermore, the device exhibited an average mechano-sensitivity of 20±1.4 V kPa-1 under 10 kPa and 13.45±2.3 V kPa-1 under 10-100 kPa conditions. The improved performance of the M-PENG is attributed to the stretching and in situ poling during electrospinning, as well as the synergistic contribution of the BT NPs and GNS to the piezoelectric performance …