Scalable Paper Supercapacitors for Printed Wearable Electronics

Abstract

Printed paper-based electronics offers solutions to rising energy concerns by supplying flexible, environmentally friendly, low-cost infrastructure for portable and wearable electronics. Herein, we demonstrate a scalable spray-coating approach to fabricate tailored paper poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/cellulose nanofibril (CNF) electrodes for all-printed supercapacitors. Layer-by-layer spray deposition was used to achieve high-quality electrodes with optimized electrode thickness. The morphology of these electrodes was analyzed using advanced X-ray scattering methods, revealing that spray-coated electrodes have smaller agglomerations, resulting in a homogeneous film, ultimately suggesting a better electrode manufacturing method than drop-casting. The printed paper-based supercapacitors exhibit an areal capacitance of 9.1 mF/cm 2 , which provides enough energy to power electrochromic indicators. The measured equivalent series resistance (ESR) is as low as 0.3 Ω, due to improved contact and homogeneous electrodes. In addition, a demonstrator in the form of a self-powered wearable wristband is shown, where a largearea (90 cm 2 ) supercapacitor is integrated with a flexible solar cell and charged by ambient indoor light. This demonstration shows the tremendous potential for sequential coating/printing methods in the scaling up of printed wearables and self-sustaining systems.

Porous Structural Microfluidic Device for Biomedical Diagnosis: A Review

“…Paper has unique advantages over other materials in terms of low cost, flexibility and self-driven fluid pumping, thus making it widely used in various fields of wearable devices and human health monitoring [ 88 , 89 , 90 , 91 , 92 ]. Paper-based microfluidics is a fast-growing field because the inherently porous structure of paper provides a separate site for transporting liquids by capillary forces [ 1 , 93 , 94 , 95 ].…”

Recent research progress of paper-based supercapacitors based on cellulose

“…In addition to the construction of paper based supercapacitor by spraying active ink on cellulose paper, the preparation of cellulose based conductive ink has also been studied in recent years. For example, Engquist et al [115,116] from Linköping University in Sweden reported two research efforts on inkjet printing of cellulosebased inks. As shown in Figure 12E, the team prepared a printable cellulose based ink by mixing CNF with conductive polymer PEDOT:PSS.…”

“…(G)Based on the schematic diagram of solar self-charging equipment. (H)Electrochemical performance test of self-charging devices [116].…”

Elucidating the Bulk Morphology of Cellulose‐Based Conducting Aerogels with X‐Ray Microtomography

“…Specifically, the conducting polymer poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), has been widely used in composites with cellulose [ 16 ] due to its high electronic and ionic conductivity, [ 24 ] high specific capacitance, and thermoelectric properties enabling the formation of active materials for supercapacitors, [ 25–30 ] thermoelectric generators, [ 31 ] sensors, [ 32 ] and actuators. [ 33 ] PEDOT:PSS is processed from an aqueous solution and therefore can be directly mixed with cellulose pulp or more refined forms of cellulose such as NFC to form functional composites with paper‐like structures or even 3D porous aerogels.…”

“…There are several examples in the literature where cellulose is combined with synthetic materials [11,12] such as inorganic nanoparticles, [13] ionic liquids, [14] carbon nanotubes, [15] and conducting polymers [16] for applications in non-traditional areas such as energy [17] and biomedical devices, [18] water treatment, [19] optical metamaterials, [20,21] and smart textiles. [22,23] Specifically, the conducting polymer poly(3,4ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), has been widely used in composites with cellulose [16] due to its high electronic and ionic conductivity, [24] high specific capacitance, and thermoelectric properties enabling the formation of active materials for supercapacitors, [25][26][27][28][29][30] thermoelectric generators, [31] sensors, [32] and actuators. [33] PEDOT:PSS is processed from an aqueous solution and therefore can be directly mixed with cellulose pulp or more refined forms of cellulose such as NFC to form functional composites with paper-like structures or even 3D porous aerogels.…”