Inkjet-Printed High-Performance Flexible Micro-Supercapacitors with Porous Nanofiber-Like Electrode Structures

Flexible planar micro-supercapacitors (MSCs) with unique loose and porous nanofiber-like electrode structures are fabricated by combining electrochemical deposition with inkjet printing. Benefiting from the resulting porous nanofiber-like structures, the areal capacitance of the inkjet-printed flexible planar MSCs is obviously enhanced to 46.6 mF cm⁻², which is among the highest values ever reported for MSCs. The complicated fabrication process is successfully averted as compared with previously reported best-performing planar MSCs. Besides excellent electrochemical performance, the resultant MSCs also show superior mechanical flexibility. The as-fabricated MSCs can be highly bent to 180° 1000 times with the capacitance retention still up to 86.8%. Intriguingly, because of the remarkable patterning capability of inkjet printing, various modular MSCs in serial and in parallel can be directly and facilely inkjet-printed without using external metal interconnects and tedious procedures. As a consequence, the electrochemical performance can be largely enhanced to better meet the demands of practical applications. Additionally, flexible serial MSCs with exquisite and aesthetic patterns are also inkjet-printed, showing great potential in fashionable wearable electronics. The results suggest a feasible strategy for the facile and cost-effective fabrication of high-performance flexible MSCs via inkjet printing.