Boron-doped porous carbon patterns for high volumetric energy density micro-supercapacitors

김철호,문준혁 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Micro-supercapacitors have great potential to complement or even replace lithium-ion batteries. Current micro-supercapacitors are capable of higher power densities than conventional lithium thin-film batteries, but still have low energy storage densities. Here, we demonstrate pore-patterned carbon electrodes for micro-supercapacitors. We implement boron doping to achieve high electrical conductive structure and, also improve pseudocapacitance. The solid-state MSC with our electrodes shows a remarkably high volumetric energy density of 7.1 mWh/㎤.

Fabrication of a Stretchable Solid-State Micro-Supercapacitor Array

Kim, Daeil,Shin, Gunchul,Kang, Yu Jin,Kim, Woong,Ha, Jeong Sook American Chemical Society 2013 ACS NANO Vol.7 No.9

<P>We fabricated a stretchable micro-supercapacitor array with planar SWCNT electrodes and an ionic liquid-based triblock copolymer electrolyte. The mechanical stability of the entire supercapacitor array upon stretching was obtained by adopting strategic design concepts. First, the narrow and long serpentine metallic interconnections were encapsulated with polyimide thin film to ensure that they were within the mechanical neutral plane. Second, an array of two-dimensional planar micro-supercapacitor with SWCNT electrodes and an ion-gel-type electrolyte was made to achieve all-solid-state energy storage devices. The formed micro-supercapacitor array showed excellent performances which were stable over stretching up to 30% without any noticeable degradation. This work shows the strong potential of a stretchable micro-supercapacitor array in applications such as wearable computers, power dressing, electronic newspapers, paper-like mobile phones, and other easily collapsible gadgets.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2013/ancac3.2013.7.issue-9/nn403068d/production/images/medium/nn-2013-03068d_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn403068d'>ACS Electronic Supporting Info</A></P>

Stretchable patterned graphene gas sensor driven by integrated micro-supercapacitor array

Yun, Junyeong,Lim, Yein,Jang, Gwon Neung,Kim, Daeil,Lee, Seung-Jung,Park, Heun,Hong, Soo Yeong,Lee, Geumbee,Zi, Goangseup,Ha, Jeong Sook Elsevier 2016 Nano energy Vol.19 No.-

<P><B>Abstract</B></P> <P>We report on the fabrication of a stretchable patterned graphene gas sensor driven by integrated micro-supercapacitor (MSC) array on the same deformable substrate. The integrated MSCs consist of polyaniline-wrapped multi-walled carbon nanotube electrodes and an ionogel electrolyte of poly(ethylene glycol)diacrylate and 1-ethyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide. The deformable soft Ecoflex substrate was designed to suppress the applied strain on the gas sensor and MSCs via insertion of stiff platforms of SU-8 underneath and serpentine electrical interconnections of polymer-encapsulated long and narrow Au thin film. The fabricated MSC array demonstrated stable electrochemical performance under a uniaxial strain of 50% and a biaxial strain of 40%, maintaining its initial characteristics even after 1000 cycles of repetitive uniaxial and biaxial stretching. Furthermore, the patterned-graphene sensor detected NO<SUB>2</SUB> gas for longer than 50min via integration with MSCs using the serpentine interconnections even under uniaxial stretching by 50%. This work suggests fundamental progress towards the development of stretchable environmental sensor system which can be driven by integrated energy storage devices without external long wire connections to power source.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We fabricate a stretchable gas sensor driven by integrated microsupercapacitor array. </LI> <LI> Stretchable substrate uses serpentine interconnections with embedded stiff platforms. </LI> <LI> Patterned graphene sensor stably detects NO<SUB>2</SUB> gas upon 50% uniaxial stretching. </LI> <LI> With energy supplied by micro-supercapacitors, the gas sensor is operated for 50min. </LI> <LI> Performance of micro-supercapacitors retains stable under repeated biaxial stretching. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Paper-Based Solid-State Micro-supercapacitors Fabricated by Hydrophobic Wax Barrier Printing

김나연,Oh In Hyeok,장석태 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.3

Flexible and small-scale energy storage technologies are critical for future applications such as wearable electronics. In this context, paper has emerged as a lightweight, low-cost, and ecologically friendly fl exible substrate for energy storage devices. This paper presents a simple method for fabricating a micro-supercapacitor (MSC) using a wax printing approach that can achieve high resolution without requiring complex processes. In addition, the developed MnO 2 –Au-paper (MAP) microelectrodes with high porosity exhibit enhanced charge and ion transfer while maintaining a stable fl exibility. The solidstate micro-supercapacitor delivers a very large areal capacitance of 624.32 mF cm −2 at 0.2 mA cm −2 and is stable under external stress. The highest energy and power densities obtained for the present MSCs (55.5 μWh cm −2 and 1.59 mW cm −2 , respectively), are much larger than those previously reported for pseudocapacitive MSCs, including fl exible ones.

Research of Control Strategy on DC Side of Hybrid Energy Storage in Micro Grid

Tieyan Zhangi,Di Bai,Zheng Yang,Zhibin Long,Baiyu Gao 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.9

The uncertainty and fluctuation brought by distributed type of intermittent power generation in micro grid bring huge challenges to power quality of micro grid in isolating operation and power control in parallel operation. Nevertheless energy storage is able to well solve this problem. Hybrid energy storage integrates the respective advantages of storage battery and supercapacitor to have improved the performance of energy storage system. Service life of storage battery is tightly related to its charging/discharging times and problem of frequent charging/discharging storage battery still exists in current hybrid energy storage technology. In this paper, it respectively puts forward control strategies for storage battery and supercapacitor. As to control strategy for storage battery, it uses double-layered control strategy, namely, single loop control and power hysteresis control, to feedback low-frequency fluctuation of power and reduce charging/discharging frequency of storage battery. As to control strategy for supercapacitor, it uses inner loop current with power to control voltage in outer loop so as to feedback high-frequency fluctuation of power and it is able to well maintain stability of DC bus voltage. Simulation results suggest the validity of aforesaid control strategies.

Pseudocapacitve layer-coated 3D carbon pattern electrodes for micro-supercapacitors

김철호,문준혁 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Micro-supercapacitors (MSCs) with high energy density are in great demand due to its wide application for energy storage devices. Here, we demonstrate a composite electrode of a 3D carbon pattern fabricated using carbonization of 3D interference lithography, coated with a thin film shell of MnO₂ and PANI by electrodeposition. Then, plasma etching is performed on the electrode to obtain an interdigitated electrode, and a polymer electrolyte is applied to complete the MSC. MnO₂ and PANI-coated carbon pattern MSCs achieve high areal capacitance with excellent cycle stabilities.

Hierarchical porous carbon pattern electrodes for micro-supercapacitors

김철호,문준혁 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Micro-supercapacitors (MSCs) are attractive for applications in nextgeneration mobile and wearable. However, many previous MSCs have often exhibited a low volumetric energy density because of the nonuniform pore structure of the electrodes. To address this issue, we to fabricate 3D sub-micrometer pore-patterned carbon film. Furthermore, a hierarchical pore-patterned carbon (hPC) electrode was formed by introducing a micropore by chemical etching. The hPC electrodes were applied to solid-state MSCs. We achieved a constant volumetric capacitance and a corresponding volumetric energy density for electrodes of various thicknesses.

Stretchable array of high-performance micro-supercapacitors charged with solar cells for wireless powering of an integrated strain sensor

Yun, Junyeong,Song, Changhoon,Lee, Hanchan,Park, Heun,Jeong, Yu Ra,Kim, Jung Wook,Jin, Sang Woo,Oh, Seung Yun,Sun, Lianfang,Zi, Goangseup,Ha, Jeong Sook Elsevier 2018 Nano energy Vol.49 No.-

<P><B>Abstract</B></P> <P>The aim of this paper is to report on the fabrication of a stretchable array of high-performance solid-state micro-supercapacitors (MSCs), which can be charged with integrated, commercial Si-based solar cells (SCs). This would facilitate the powering of an integrated strain sensor. The planar MSCs comprised electrodes of potentiostatically deposited polypyrrole, on spray-coated multi-walled carbon nanotube film, and a gel-type electrolyte of LiCl/polyvinyl alcohol with a redox additive of 1-methyl-3-propylimidazolium iodide. The fabricated MSC achieved an areal capacitance of 5.17 mF cm<SUP>−2</SUP>. After 5000 charge/discharge cycles, the MSC retained 80% of their initial capacitance. A strain sensor was fabricated utilizing a composite film of fragmentized graphene foam and polydimethylsiloxane. Such fabricated twelve parallel connected MSCs, a strain sensor, and SCs were integrated on a single deformable polymer substrate with embedded stiff platforms of negative epoxy series resist (SU-8) via long serpentine interconnections of polyimide encapsulated Ti/Pt metal film for mechanical stability under stretching. After 1000 repetitive biaxial stretching/releasing cycles by 30%, no noticeable change was observed in the charge/discharge behavior of the MSC array. Furthermore, both the photo-charge/discharge characteristics and electrochemical performance remained stable. When the whole integrated system was attached to the wrist, the integrated strain sensor could detect both externally applied strain and the arterial pulse using the energy stored in the MSCs from the SCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We fabricate a stretchable array of micro-supercapacitors charged by solar cells for wireless powering of the integrated strain sensor. </LI> <LI> Serpentine interconnections with the embedded stiff SU-8 platform enable stable performance under stretching deformation. </LI> <LI> Strain sensor detects pulse signal of the radial artery and bending motion of the wrist. </LI> <LI> The sensor is operated for 100 s with energy supplied by the integrated array. </LI> <LI> Under repeated biaxial stretching, the stretchable array retains stable performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Simple fabrication of flexible asymmetric mciro-supercapacitors by using pneumatic printing and intense pulsed white light technique

송치호,황정욱,안수현,안희준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Recently, the rapid development of foldable, rollable displays and electronic devices are accelerating an increasing necessity of flexible and miniaturized energy storages such as micro-supercapacitors (MSCs). However, many attempts have drawbacks such as materials, energy and time consuming and require multiple steps. In this study, we have fabricated flexible asymmetric hybrid MSCs by using a printing technique and an intense pulsed white light (IPWL) technology. By these methods, micron-sized electrode patterns can be easily fabricated on flexible substrate and reduced graphene oxide and metal oxide micro-patterns can be accomplished within milliseconds by irradiating the IPWL with high energy density on graphene oxide and metal oxide precursor patterns, which is exceptionally faster than other grapheme reduction and metal oxide formation methods. The prepared micropatterns are utilized as MSC electrodes, and their electrochemical performance and characteristics are discussed.

Aligned Carbon Nanotubes-Embedded Agarose Gel Composite Fiber Electrodes for Wearable Fiber Micro-Supercapacitors

송은석,김성곤,이승민,신주비 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

We design here carbon nanotubes (CNTs)-embedded agarose gel composite yarn electrodes for flexible and wearable fiber micro- supercapacitors (mSCs). Extrusion process makes CNTs and their bundles align in an agarose filament matrix and such a shear-induced alignment is more obvious as the diameter of the filament gets narrower, leading to high electrical conductivity (8.3 S cm^-1). The 1D composite (aCNT) fiber electrodes are also mechanically stable to form two-ply fiber mSCs that are integrated by twisting the aCNT electrodes with a PVA/H3PO4 solid electrolyte. The resulting fiber SC shows high volumetric capacitance (~1.2 F cm^-3), good rate retention (~90%), long cycle life under repeated charging/discharging (3000 cycles) and even deformation. The superior performance is due to high electrical conductivity along the aligned CNTs and large effective electrode surface area that can be accessible through the ion conducting agarose.