Miniaturized and flexible power resources such as supercapacitors with resistance of high voltage play a critical role as potential energy storage devices for implantable and portable electronics because of their convenience, high power density, and long-term stability. Herein, we propose a novel strategy for the fabrication of high voltage microsupercapacitors (HVMSCs) employing porous laser-induced graphene (from polyimide films with alkalization treatment) followed by laser carving of the polyvinyl alcohol/H3PO4 gel electrolyte to realize a series assembly of supercapacitors and significantly increase the voltage resistance. The results elucidated that HVMSCs (3 mm × 21.15 mm) exhibited excellent capacitive performance including exceptional potential window (10 V), high areal capacitance (244 μF/cm2), acceptable power density (274 μW/cm2) and energy density (3.22 μW h/cm2), good electrochemical stability and flexibility at different bending status (0, 45, 90, 135, and 180°), as well as impressive voltage durability more than 5 V in smaller scale (0.5 mm × 5.5 mm). As such, the HVMSCs have great potential to be integrated with microcircuit modules for the next-generation self-powered systems and storage electronic devices in high voltage applications.
Keywords: energy storage; flexible; high voltage micro-supercapacitors; high-voltage electronic devices; laser-induced graphene.