Laser printing-based high-resolution metal patterns with customizable design and scalable fabrication of high-performance flexible planar micro energy storage devices

The ever-increasing demand for light, thin, flexible, and small-sized smart electronics has developed a market for planar micro energy storage devices with high performance, flexibility, and robust integration, that is not mature yet. Here, a high-resolution patterned platinum (Pt) layer that can be designed/shaped as required is prepared by printing sacrificial patterns (SPs) using a commercial laser printer. MnO2-based micro-supercapacitors (MSCs) are successfully prepared on commercial Polyethylene terephthalate (PET) via electrodeposition. Because of the large surface area and large number of active sites of the nano-branch-shaped MnO2, the MnO2/Pt MSCs exhibit excellent volumetric specific capacitance (615.14F cm-3) as well as an ultrahigh volumetric power density (11.677 Wh cm-3) and energy density (54.679 mWh cm-3). In addition, the MnO2/Pt MSCs possess excellent flexibility and integration, with capacitance retention when bend to 180 degrees and can be designed to connect in series or parallel for delivering the desired output voltage and capacitance. Furthermore, planar Zn-MnO2 batteries are successfully prepared through step-by-step electrodeposition. Simultaneously, a flexible energy conversion storage system is constructed by connecting solar cells and electrical appliances with the fabricated MSCs, demonstrating that this straightforward strategy is extremely promising for future application in microcircuits and flexible wearable smart textiles.