Fabrication of a Stretchable Solid-State Micro-Supercapacitor Array

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146

degree of the entire electronic systems. In the integrated flexible electronic system, energy storage devices [14,[16][17][18][19][20] play important roles in connecting the preceding energy harvesting devices and the following energy utilization devices (Figure 1). Rechargeable secondary batteries and supercapacitors (SCs) are two typical energy storage devices. [21] Several excellent review papers [21][22][23][24][25][26] reported significant progresses achieved in flexible lithium-ion batteries (LIBs) and SCs by taking advantage of novel electrode materials, current collectors, and solid-state electrolytes. The application areas and lifetime of flexible power sources strongly depend on their mechanical deformation tolerance and the electrical property retention under deformation. Qualified flexible power sources should be able to endure high strain induced by external mechanical deformation, such as bending, compressing, stretching, folding, and twisting, while maintaining their electrochemical performance stability and structural integrity. Therefore, the mechanical reliability assessment and electrical property analysis of flexible devices need to be given much attention for future application.Tolerance in bending into a certain curvature is the major mechanical deformation characteristic of flexible energy storage devices. Thus far, several bending characterization parameters and various mechanical methods have been proposed to evaluate the quality and failure modes of the said devices by investigating their bending deformation status and received strain. Some of these mechanical metrologies were derived from the early research on flexible semiconductor devices of micro-electromechanical system (MEMS) [27,28] and TFTs. [29] However, comparing those numerous measurement data with one another is difficult because of the various theories and methods adopted by different research groups and the lack of unified assessment criteria. [26] The flexibility of flexible devices is generally realized not only by use of intuitive soft electrode materials but also by optimizing their mechanical structural design. [25] Detailed analysis on bending mechanics combining experimental and theoretical results provide not only reliable test methods to describe the bending state but also guidance for configuration design of devices against mechanical failure.The current review emphasizes on three main points: (1) key parameters that characterize the bending level of flexible energy storage devices, such as bending radius, bending Flexible energy storage devices with excellent mechanical deformation performance are highly required to improve the integration degree of flexible electronics. Unlike those of traditional power sources, the mechanical reliability of flexible energy storage devices, including electrical performance retention and deformation endurance, has received much attention. To provide the guideline for the construction design of devices, the strain distribution and failure modes in the entire architecture should b...

Section: Cylinder With a Given Diametermentioning

confidence: 99%

Section: Architectural Design Of Flexible Energy Storage Devicesmentioning

confidence: 99%

Mechanical Analyses and Structural Design Requirements for Flexible Energy Storage Devices

Mao

Meng

Ahmad

et al. 2017

190

146

“…In 2013, a stretchable micro-supercapacitor array with planar SWCNT electrodes and an ionic-liquid-based triblock copolymer electrolyte was reported. [73] The narrow and long serpentine metallic interconnections were encapsulated with polyimide thin film to ensure that they were within the mechanical neutral plane (Figure 8e). The metallic bridging interconnects will take most of the mechanical energy upon stretching, to protect the micro supercapacitor arrays from deformation.…”

Section: D Film-based Configurationmentioning

confidence: 99%

Toward Soft Skin‐Like Wearable and Implantable Energy Devices

Gong

Cheng

2017

187

130

The development of ultra‐compliant power sources is crucial for their seamless integration with next‐generation skin‐like wearable and implantable biomedical systems for long‐term health monitoring. Toward this goal, stretchable energy storage and conversion devices (ESCDs), including supercapacitors, lithium‐ion batteries (LIBs), solar cells, and generators are now attracting intensive worldwide research efforts. The purpose of this review is to discuss the latest achievements in the development of such stretchable energy devices in the context of biomedical applications. We first review the viable strategies and methodologies of fabricating stretchable energy storage and conversion devices. Then, we focus on description of various types of soft energy devices from a materials point of view. Furthermore, we discuss the challenges and opportunities in the design of truly conformal soft energy systems, including various key parameters, such as energy density, stability, and scalability.

“…For example, CNT or graphene electrodes generally require the prestrain method for high stretchability, making them difficult to integrate with other stretchable transparent electronics. [184] In addition, despite the progress of nanocarbon-based STECs, their conductance is still low level, which requires additional current collectors. [177] As mentioned above, transparent nanocarbon films should be very thin due to their relatively high absorption coefficient and broad absorption spectral range, leading to the low energy capacity of the device.…”

Section: Supercapacitorsmentioning

confidence: 99%

Deformable and Transparent Ionic and Electronic Conductors for Soft Energy Devices

Park

Parida

Lee

2017

The recent boom in deformable or stretchable electronics, flexible transparent displays/screens, and their integration into the human body has facilitated the development of multifunctional energy devices that are stretchable, transparent, wearable, and/or biocompatible while meeting the energy or power requirements. The development of soft energy systems begins with the preparation of relevant conductors and the design of innovative device configurations. In this study, recent advances and trends in stretchable and transparent electronic and ionic conductors are reviewed coupled with the growing efforts to use them for soft energy storage and conversion systems. Stretchable transparent ionic conductors present possibilities for use as current collectors and electrolytes in soft electronic/energy devices, providing novel insight into biofriendly systems for an effective human–machine interaction. Moreover, representative examples that demonstrate soft energy devices based on stretchable transparent ionic/electronic conductors are discussed in detail. Furthermore, the challenges and perspectives of developing novel stretchable transparent conductors and device configurations with tailored features are also considered.