Flexible Planar-Integrated Micro-Supercapacitors from Electrochemically Exfoliated Graphene as Advanced Electrodes Prepared by Flash Foam-Assisted Stamp Technique on Paper

One of the key challenges of integrated energy storage devices is to develop a simple, low-cost, and environmental-friendly planar patterning technology. Herein, an ingenious and feasible laser-engraved flash foam-assisted stamp technique of preparing flexible paper-based planar-integrated micro-supercapacitors based on interdigital electrodes of self-depositing electrochemically exfoliated graphene is proposed. The as-synthesized flexible paper-based planar-integrated graphene micro-supercapacitors exhibit excellent electrochemical performances with a remarkable area-specific capacitance of 3.1 mF cm(-2), and an excellent cycling stability in that capacitance retention reaches 95.8% even after 10 000 cycles. Furthermore, the paper-based graphene micro-supercapacitors are bent at different angles without significant electrochemical performance loss, and thus have outstanding mechanical flexibility. Therefore, such flexible paper-based planar-integrated graphene micro-supercapacitors are expected to be applied in flexible wearable and portable electronics.