Tandem Self-Powered Flexible Electrochromic Energy Supplier for Sustainable All-Day Operations

Self-powered wearable energy suppliers are highly desirable for next-generation smart electronic microsystems. However, it is still challenging to achieve an all-day operating self-powered energy device via the tandem integration strategy. Herein, a tandem self-powered flexible energy supplier (SPFES) is proposed to “harvest and store” energy from sunlight (outdoor), dim-light (indoor), and human body motion. In this novel device design, two flexible transparent electrodes are shared by three functional components: organic photovoltaic, triboelectric nanogenerator, and electrochromic supercapacitor. Interestingly, the SPFES shows distinctive in-built features including energy indication, self-modulation, and self-protection. When compared to mechanically stacked devices, the SPFES avoids unnecessary encapsulation and external connections, resulting in a thinner device with a higher power-to-weight ratio (up to 110%). The concept of the SPFES paves an elegant route toward designing multi-functional flexible energy-harvest-storage devices for all-day operational wearable applications.