Dual Enhancement in Output Voltage and Energy of Droplet Electricity Generator via a Composite Dielectric Layer Design

Droplet electricity generators (DEGs) that generate electricity through the interplay between water and the dielectric materials have attracted growing research interest due to their remarkable output voltage. However, conventional DEG design faces a critical trade-off: regulating the properties of dielectric materials, such as thickness or permittivity, can enhance output voltage yet weaken transferred charge. Here, a fluorinated ethylene propylene (FEP)/multi-walled carbon nanotubes (MWCNTs)/polydimethylsiloxane (PDMS) composite-based droplet electricity generator (FMP-DEG) is presented to overcome the voltage-charge trade-off and thus achieve an enhanced energy conversion efficiency of 4.96%. With the optimized composite parameters, FMP-DEG achieves dual enhancement in output voltage (248 V) and output energy (5.23 µJ), which are 1.5 times and twice higher than conventional DEGs, respectively. Benefiting from the excellent electrical performance, FMP-DEG can successfully illuminate 68 LEDs or power a thermohygrometer via a capacitor storage. The design provides a simple yet feasible design strategy to resolve the voltage-charge trade-off in DEGs and pave the way toward scalable renewable energy solutions.