Integrated self-charging power unit with flexible supercapacitor and triboelectric nanogenerator

With the rapid development of wearable devices and portable electronics, highly efficient and stable self-powered systems are in great demand. However, most harvesting and storage devices of such systems are separate units, which reduce the power density and limit their applications. In this work, we implemented an integrated sandwich-shaped, self-charging power unit (SCPU) with a wrinkled PDMS-based triboelectric nanogenerator and CNT/paper-based solid-state supercapacitor. During ambient vibration process, this SCPU could simultaneously harvest and store energy, efficiently converting mechanical energy into electrochemical energy. The self-charging capability of this SCPU is demonstrated by periodic compressive stress, charging 900 mV within 3 h. Additionally, using three serially connected SCPUs as power supply, it could drive a commercial calculator working continuously and an electrochromic device as a smart window during the coloration and bleaching processes. Considering its efficient structure and facile fabrication, this novel integrated SCPU provides a feasible solution for sustainable power supply and shows great potential in micro-energy fields and self-powered systems.