Biomass carbon-based flexible micro-supercapacitor integrated self-powered energy storage microsystem

The miniaturization of flexible wearable electronic devices and corresponding energy storage components is a prominent trend in current technological development. As a promising option for micro-energy storage, micro-supercapacitors (MSCs) could yield an outstanding solution for replacing traditional batteries if combined with triboelectric nanogenerators (TENGs) to build a self-powered energy storage microsystem integrating energy harvesting and storage. Herein, this work proposes to prepare N-doped hierarchical porous carbon nanomaterials using orange peel (low-cost biomass), which serve as microelectrodes for MSCs. Meanwhile, a flexible mask ink-spraying method is developed to enable the batch fabrication of multiple MSCs in parallel for improved reproducibility and efficiency. Notably, the synthesized N-doped biomass carbon features an ultrahigh specific surface area ( S BET , 2675.23 m 2  g −1 ), along with outstanding capacitive performance—achieving a specific capacitance of 529 F g −1 (1 A g −1 , aqueous electrolyte) and an excellent areal capacitance of 130 mF·cm −2 (3 mA·cm −2 , gel electrolyte). Additionally, a flexible TENG with voltage of 500 V and current of 304 μA is fabricated via 3D printing technology. The self-powered energy storage microsystem is further constructed by integrating the as-fabricated MSC with the 3D printed TENG. The biomass based MSC can be rapidly charged to 0.55 V within 70 s via 3D printed flexible TENG. This work not only promotes the practical application of MSCs in wearable electronics and self-powered sensor networks, but also offers a sustainable route for biomass waste valorization. In the future, self-powered energy storage microsystems can be integrated with flexible sensors and actuators, showing broad application prospects in the Internet of Things, portable medical devices, and distributed intelligent systems.