Electrochemical performance of a coaxial fiber-shaped asymmetric supercapacitor based on nanostructured MnO₂/CNT-web paper and Fe₂O₃/carbon fiber electrodes

Patil, Bebi,Ahn, Suhyun,Yu, Seongil,Song, Hyeonjun,Jeong, Youngjin,Kim, Ju Hwan,Ahn, Heejoon Elsevier 2018 Carbon Vol.134 No.-

<P><B>Abstract</B></P> <P>The fiber-shaped supercapacitor is a promising energy storage device in wearable and portable electronics because of its high flexibility, small size, and light weight. However, most of the reported fiber-shaped supercapacitors have exhibited low capacitance and energy density due to the limited surface area between the two fiber electrodes and operating voltage range. Herein, we successfully developed a coaxial fiber-shaped asymmetric supercapacitor (CFASC) made from MnO<SUB>2</SUB>/CNT-web paper as a cathode coupled with Fe<SUB>2</SUB>O<SUB>3</SUB>/carbon fiber as an anode with a high operating voltage of 2.2 V. The prepared CFASC device showed a high volumetric energy density of 0.43 mWh cm<SUP>−3</SUP> at a power density of 0.02 W cm<SUP>−3</SUP>, which is comparable to those of previously reported fiber-shaped supercapacitors. Additionally, CFASC exhibited good rate capability, long cycle life, and high volumetric capacitance (0.67 F cm<SUP>−3</SUP>) with excellent flexibility. The promising performance of CFASC illustrated its potential for portable and wearable energy storage devices.</P> <P><B>Graphical abstract</B></P> <P>The coaxial fiber-shaped asymmetric supercapacitor (CFASC) was successfully developed by simply wrapping the Fe<SUB>2</SUB>O<SUB>3</SUB>/CFs negative electrode with the PVA-LiClO<SUB>4</SUB> gel electrolyte-coated MnO<SUB>2</SUB>/CNT-web paper positive electrode. This CFASC can be operated at large potential windows up to 2.2 V, resulting in high specific energy, and showed excellent cycling stability and device flexibility.</P> <P>[DISPLAY OMISSION]</P>

Simple and novel strategy to fabricate ultra-thin, lightweight, stackable solid-state supercapacitors based on MnO₂-incorporated CNT-web paper

Patil, Bebi,Ahn, Suhyun,Park, Changyong,Song, Hyeonjun,Jeong, Youngjin,Ahn, Heejoon Elsevier 2018 ENERGY Vol.142 No.-

<P><B>Abstract</B></P> <P>Thin, lightweight, stackable, solid-state supercapacitors are in great demand in the electronics industry because of their use in miniaturized devices. Herein, we report a simple and novel strategy to fabricate ultra-thin, lightweight, and stackable symmetric supercapacitors using MnO<SUB>2</SUB>-incorporated carbon nanotube (CNT)-web paper. SEM and TEM analyses revealed a uniform nanometer-scale coating of MnO<SUB>2</SUB> on the individual fibers of the CNT-web paper after simple deposition at room temperature. The network structure of free-standing conductive CNT-web paper provides a short diffusion path, allowing for complete utilization of MnO<SUB>2</SUB> in the charge storage process. A MnO<SUB>2</SUB>/CNT-web paper electrode showed an excellent areal capacitance of 135 mF cm<SUP>−2</SUP> at 5 mV s<SUP>−1</SUP> with a remarkable capacitance retention of 95% after 10,000 cycles. A symmetric solid-state supercapacitor containing MnO<SUB>2</SUB>/CNT-web paper displayed a high areal capacitance of 57 mF cm<SUP>−2</SUP> with an energy density of 0.018 mWh cm<SUP>−2</SUP> and a capacitance retention as high as 86% after 10,000 cycles. In addition, the voltage and capacitance were tripled by simply stacking three symmetric supercapacitors and connecting them in series and in parallel, respectively. We are optimistic that the excellent performance of the ultra-thin CNT-web paper-based supercapacitors demonstrated here will facilitate the development of compact supercapacitor banks in the near future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ultra-thin and stackable supercapacitors are fabricated using a simple strategy. </LI> <LI> MnO<SUB>2</SUB>/CNT-web paper electrode shows excellent areal capacitance and life cycle. </LI> <LI> Symmetric supercapacitor is fabricated using the MnO<SUB>2</SUB>/CNT-web paper electrodes. </LI> <LI> Symmetric supercapacitor gives a high areal capacitance of 57 mF cm<SUP>−2</SUP> at 5 mV s<SUP>−1</SUP>. </LI> <LI> Stacked supercapacitors exhibit three-fold higher supercapacitive performance. </LI> </UL> </P>

Flexible, fiber-shaped supercapacitors with roll-type assembly

유성일,Bebi Patil,안희준 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

Afiber-shaped supercapacitor (FSC) with a unique roll-type configuration is developed by simply rollingpolyaniline-coated carbonfiber bundle electrodes with an H2SO4/polyvinyl alcohol gel electrolyte. Theroll-type polyaniline-coated carbonfibers FSC exhibits four times higher capacitance retention than thetwist-typefiber-shaped supercapacitor and shows an energy density of 2.97 Wh kg 1 at a power densityof 4 kW kg 1, which is almost three orders of magnitude higher than that of the twist-type FSC(0.004 Wh kg 1). The enhanced performance of the roll-type FSC is attributable to its unique roll-typeconfiguration, which creates a short and consistent distance between the electrodes.

PANI//MoO3 Fiber-shaped Asymmetric Supercapacitors with Rolltype Configuration

Seongil Yu,Bebi Patil,안희준 한국섬유공학회 2020 Fibers and polymers Vol.21 No.3

An asymmetric fiber-shaped supercapacitor (FSC) with roll-type configuration, displaying high power and energydensity characteristics, has been fabricated for energy storage in wearable devices. The positive and negative electrodes of theasymmetric FSC consist of polyaniline (PANI) and MoO3, respectively, and are deposited on a carbon fiber (CF) substrateusing a chemical bath deposition method. A polyvinyl alcohol/H2SO4 gel is used as electrolyte, which also maintains the CFelectrodes in fiber form. The asymmetric PANI//MoO3 roll-type FSC exhibits a wider potential range than its symmetricPANI//PANI counterpart, resulting in higher energy and power densities. The asymmetric PANI//MoO3 roll-type FSC showsan energy density of 67.51 μWh/cm3 with a power density of 59.71 mW/cm3 at a current of 10 mA, which is more than twicethe energy density of symmetric PANI//PANI roll-type FSC (30.42 μWh/cm3 and 25.12 mW/cm3).

Co₃Se₄ nanosheets embedded on N-CNT as an efficient electroactive material for hydrogen evolution and supercapacitor applications

Bose, Ranjith,Patil, Bebi,Rajendiran Jothi, Vasanth,Kim, Tae-Hyun,Arunkumar, Paulraj,Ahn, Heejoon,Yi, Sung Chul THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.65 No.-

<P><B>Abstract</B></P> <P>Co<SUB>3</SUB>Se<SUB>4</SUB> on nitrogen doped carbon nanotube (N-CNT) with applications for supercapacitor and hydrogen evolution reaction (HER) is synthesized by pyrolysis and solvothermal processes. The catalyst due to improved electrical conductivity and increased rate of removal of H<SUB>2</SUB> liberated, delivers a high HER activity, by reaching <I>η</I> <SUB>10</SUB> at 174mV and 240mV, Tafel slope of 73.2 and 43.8mVdec<SUP>−1</SUP> in alkaline and acidic medium respectively. Co<SUB>3</SUB>Se<SUB>4</SUB>/N-CNT as supercapacitor electrodes, yields a capacitance of 114Fg<SUP>−1</SUP> at a 2mVs<SUP>−1</SUP> scan rate, with an excellent capacitive retention of 96% of the initial capacitance after 5000 cycles.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Flexible, fiber-shaped supercapacitors with roll-type assembly

Yu, Seongil,Patil, Bebi,Ahn, Heejoon THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2019 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.71 No.-

<P><B>Abstract</B></P> <P>A fiber-shaped supercapacitor (FSC) with a unique roll-type configuration is developed by simply rolling polyaniline-coated carbon fiber bundle electrodes with an H<SUB>2</SUB>SO<SUB>4</SUB>/polyvinyl alcohol gel electrolyte. The roll-type polyaniline-coated carbon fibers FSC exhibits four times higher capacitance retention than the twist-type fiber-shaped supercapacitor and shows an energy density of 2.97Whkg<SUP>−1</SUP> at a power density of 4kWkg<SUP>−1</SUP>, which is almost three orders of magnitude higher than that of the twist-type FSC (0.004Whkg<SUP>−1</SUP>). The enhanced performance of the roll-type FSC is attributable to its unique roll-type configuration, which creates a short and consistent distance between the electrodes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new roll-type configuration was designed for fiber-shaped supercapacitors (FSCs). </LI> <LI> The roll-type configuration maintains a short distance between the electrodes. </LI> <LI> The roll-type FSC was simply fabricated by roll-up assembly. </LI> <LI> The PANI/CF roll-type FSC exhibited high capacitance retention. </LI> <LI> The roll-type FSC showed excellent mechanical stability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A fiber-shaped supercapacitor (FSC) with a unique roll-type configuration was developed by simply rolling up PANI-coated carbon fiber bundle electrodes and using a PVA–H<SUB>2</SUB>SO<SUB>4</SUB> gel electrolyte. The PANI/CF roll-type FSC exhibited better electrochemical performance than the PANI/CF twist-type FSC.</P> <P>[DISPLAY OMISSION]</P>

Flexible, Swiss roll, fiber-shaped, asymmetric supercapacitor using MnO₂ and Fe₂O₃ on carbon fibers

Cho, Sungdong,Patil, Bebi,Yu, Seongil,Ahn, Suhyun,Hwang, Jeonguk,Park, Changyong,Do, Kwanghyun,Ahn, Heejoon Elsevier 2018 ELECTROCHIMICA ACTA Vol.269 No.-

<P><B>Abstract</B></P> <P>We report a successful demonstration of a Swiss roll, fiber-shaped, asymmetric supercapacitor (FSASC) fabricated with MnO<SUB>2</SUB> as a positive electrode and Fe<SUB>2</SUB>O<SUB>3</SUB> as a negative electrode, both on carbon fibers as the current collector, with a high operating voltage of 2.0 V. The suggested Swiss roll FSASC device exhibited a high gravimetric energy density of 33.1 Wh kg<SUP>−1</SUP> and a volumetric energy density of 0.16 mWh cm<SUP>−3</SUP>, with excellent rate capability, cycling stability, and coulombic efficiency. Additionally, the Swiss roll FSASC showed great durability and flexibility under mechanical stress. The promising performance of the Swiss roll FSASC suggests its potential for applications in wearable and flexible energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A Swiss roll, fiber-shaped, asymmetric supercapacitor (FSASC) was fabricated via a facile method. </LI> <LI> MnO<SUB>2</SUB>/CFs and Fe<SUB>2</SUB>O<SUB>3</SUB>/CFs were used as the positive and negative electrodes, respectively, in the designed supercapacitor. </LI> <LI> The Swiss roll FSASC showed a high gravimetric energy density of 33.1 Wh kg<SUP>−1</SUP>. </LI> <LI> The Swiss roll FSASC exhibited good rate capability, long cycle life, and excellent flexibility. </LI> <LI> The Swiss roll FSASC maintained electrochemical stability under repeated mechanical stresses. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A Swiss roll, fiber-shaped, asymmetric supercapacitor (FSASC) was successfully fabricated by simply rolling an Fe<SUB>2</SUB>O<SUB>3</SUB>/CF negative electrode and a MnO<SUB>2</SUB>/CF positive electrode with PVA-LiClO<SUB>4</SUB> gel electrolyte. This Swiss roll FSASC can be operated in large potential windows up to 2.0 V and shows excellent rate capability, cycling stability, and device flexibility.</P> <P>[DISPLAY OMISSION]</P>

Co3Se4 nanosheets embedded on N-CNT as an efficient electroactive material for hydrogen evolution and supercapacitor applications

Ranjith Bose,Bebi Patil,바산트라젠디란조띠,김태현,PAULRAJARUN KUMAR,안희준,이성철 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.65 No.-

Co3Se4 on nitrogen doped carbon nanotube (N-CNT) with applications for supercapacitor and hydrogen evolution reaction (HER) is synthesized by pyrolysis and solvothermal processes. The catalyst due to improved electrical conductivity and increased rate of removal of H2 liberated, delivers a high HER activity, by reaching η10 at 174 mV and 240 mV, Tafel slope of 73.2 and 43.8 mV dec−1 in alkaline and acidic medium respectively. Co3Se4/N-CNT as supercapacitor electrodes, yields a capacitance of 114 F g−1 at a 2 mV s−1 scan rate, with an excellent capacitive retention of 96% of the initial capacitance after 5000 cycles.