Inkjet-Printed Electrodes on A4 Paper Substrates for Low-Cost, Disposable, and Flexible Asymmetric Supercapacitors

Abstract

Printed electronics is widely gaining much attention for compact and high-performance energy-storage devices because of the advancement of flexible electronics. The development of a low-cost current collector, selection, and utilization of the proper material deposition tool and improvement of the device energy density are major challenges for the existing flexible supercapacitors. In this paper, we have reported an inkjet-printed solid-state asymmetric supercapacitor on commercial A4 paper using a low-cost desktop printer (EPSON L130). The physical properties of all inks have been carefully optimized so that the developed inks are within the printable range, i.e., Fromm number of 4 < Z < 14 for all inks. The paper substrate is made conducting (sheet resistance ∼ 1.6 Ω/sq) by printing 40 layers of conducting graphene oxide (GO) ink on its surface. The developed conducting patterns on paper are further printed with a GO-MnO nanocomposite ink to make a positive electrode, and another such structure is printed with activated carbon ink to form a negative electrode. A combination of both of these electrodes is outlaid by fabricating an asymmetric supercapacitor. The assembled asymmetric supercapacitor with poly(vinyl alcohol) (PVA)-LiCl gel electrolyte shows a stable potential window of 0-2.0 V and exhibits outstanding flexibility, good cyclic stability, high rate capability, and high energy density. The fabricated paper-substrate-based flexible asymmetric supercapacitor also displays an excellent electrochemical performances, e.g., a maximum areal capacitance of 1.586 F/cm (1023 F/g) at a current density of 4 mA/cm, highest energy density of 22 mWh/cm at a power density of 0.099 W/cm, a capacity retention of 89.6% even after 9000 charge-discharge cycles, and a low charge-transfer resistance of 2.3 Ω. So, utilization of inkjet printing for the development of paper-based flexible electronics has a strong potential for embedding into the next generation low-cost, compact, and wearable energy-storage devices and other printed electronic applications.

The direct-writing of low cost paper based flexible electrodes and touch pad devices using silver nano-ink and ZnO nanoparticles

“…The preparation of functional conductive materials has been widely investigated by several researchers for a variety of applications such as transistors, 1 displays, 2 solar cells, 3 capacitors, 4 and touch pads. 5 Among these, the touch pad is basically made of an input device for sending the signals to an appliance by mechanical touch with a nger.…”

Recent advances and prospects of inkjet printing in heterogeneous catalysis

“…50 Therefore, it is preferable to stabilize the inkjet solution using dispersing agents, and use particles with average size as small as 1/50th of the nozzle diameter. 46,51 The ink viscosity and surface tension also strongly influence the dynamics of microfluidic droplets and must be carefully controlled and/or optimized. The suggested range for viscosity in DOD inkjet printers is 1-25 mPa s. 52 Ink solutions with higher viscosity cannot release smoothly from the nozzle.…”

Soft Inkjet Circuits

“…We can learn about the potential of inkjet printing for fabricating circuits by looking at research in material science and the science of printing [1]. These research areas explored inkjet-printed electronics early on [24,48,53], printing a variety of materials, such as carbon nanotubes [58], metallic nanoparticles [5,22,23,51], graphene [54] and titanium oxide [28], among many others. As a result, it has been possible to print foldable and soft circuits [48,51], circuits on fabrics using custom inks [18], transistors [49] and super transistors [5,51,58], and memories [28].…”