High voltage micro-supercapacitors fabricated and assembled by laser carving

Miniaturized and flexible power resource like supercapacitors with resistance of high voltage plays a critical role as potential energy storage devices for implantable and portable electronics because of its convenience, high power density and long-term stability. Herein, we propose a novel strategy for the fabrication of high voltage micro-supercapacitors (HVMSCs) employing porous laser-induced-graphene (LIG) (from polyimide (PI) films with alkalization treatment) followed by laser carving of polyvinyl alcohol/H3PO4 (PVA/H+) gel electrolyte to realize 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 µWh/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.