In‐Plane Micro‐Supercapacitors for an Integrated Device on One Piece of Paper

Abstract

Portable and wearable sensors have attracted considerable attention in the healthcare field because they can be worn or implanted into a human body to monitor environmental information. However, sensors cannot work independently and require power. Flexible in-plane micro-supercapacitor (MSC) is a suitable power device that can be integrated with sensors on a single chip. Meanwhile, paper is an ideal flexible substrate because it is cheap and disposable and has a porous and rough surface that enhances interface adhesion with electronic devices. In this study, a new strategy to integrate MSCs, which have excellent electrochemical and mechanical performances, with sensors on a single piece of paper is proposed. The integration is achieved by printing Ni circuit on paper without using a precoating underlay. Ink diffusion is also addressed to some degree. Meanwhile, a UV sensor is integrated on a single paper, and the as-integrated device shows good sensing and self-powering capabilities. MSCs can also be integrated with a gas sensor on one-piece paper and can be charged by connecting it to a solar cell. Thus, it is potentially feasible that a flexible paper can be used for integrating MSCs with solar cell and various sensors to generate, store, and use energy.

Flexible Asymmetric Microsupercapacitors from Freestanding Hollow Nickel Microfiber Electrodes

“…In particular, inspection of Table S1 (Supporting Information) reveals that the freestanding nature of the Ni electrode enables assembly of a thin device exhibit comparable electrochemical performance to electrodes containing much higher loading of active materials, sometimes approaching thicknesses of thousands micrometer (an order of magnitude thicker). [19,33,41,42,51,52] Similarly, the Ragone plot in Figure 5C attests to the excellent areal energy of the Ni microtube AMSC, calculated as a function of the power densities, and shows the higher power densities that can be used by the AMSCs in comparison to previously reported MSCs. [19,33,41,42,51,52] Similarly, the Ragone plot in Figure 5C attests to the excellent areal energy of the Ni microtube AMSC, calculated as a function of the power densities, and shows the higher power densities that can be used by the AMSCs in comparison to previously reported MSCs.…”

“…Such electrodes facilitate rapid diffusion of molecules participating in the redox reactions; they are also generally thin and accordingly can be integrated in microelectronic devices. Several studies have addressed these issues by fabricating planar MSCs using porous carbon ink, [17] laboratory filter paper, [19] and electrostatic spraying of reduced graphene oxide (rGO) and carbon nanotube mixtures. Several studies have addressed these issues by fabricating planar MSCs using porous carbon ink, [17] laboratory filter paper, [19] and electrostatic spraying of reduced graphene oxide (rGO) and carbon nanotube mixtures.…”

“…[27] The data presented in Table S1 (Supporting Information) underscore the high-capacitance values achieved by the AMSCs we developed, which are in the range of hundreds mF cm −2 while the corresponding capacitance values reported for numerous thin MSCs are, in fact, in the tens of mF cm −2 for the same charging rates. [19,33,[41][42][43] Considering the dimensions of the device, a volumetric capacitance of 1. www.advelectronicmat.de was calculated; this is an especially high value accounting for the fact that the final AMSC device is thin as the nickel electrode constitutes both the support substrate and current collector. [19,33,[41][42][43] Considering the dimensions of the device, a volumetric capacitance of 1. www.advelectronicmat.de was calculated; this is an especially high value accounting for the fact that the final AMSC device is thin as the nickel electrode constitutes both the support substrate and current collector.…”

“…A final step of toluene-induced dissolution of the PS cores yielded a freestanding electrode comprising an interspersed network of hollow metallic nickel microfibers. [19,27] The mechanical resilience of the hollow microfiber Ni electrode upon physical deformation was evaluated ( Figure 2D,E). Scanning electron microscopy (SEM) images in Figure 2A-C show the intertwined network of highly uniform Ni microfibers, exhibiting outer diameters of 3.4 ± 0.6 µm and inner diameter of 1.8 ± 0.2 µm.…”

Stretchable Supercapacitors as Emergent Energy Storage Units for Health Monitoring Bioelectronics

“…Reproduced with permission. [275] Copyright 2017, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Reproduced with permission.…”