Low-cost superior symmetric solid-state supercapacitors based on MWCNTs/MnO₂ nanocomposite thin film

Chodankar, Nilesh R.,Ji, Su-Hyeon,Kim, Do-Heyoung Elsevier 2017 JOURNAL- TAIWAN INSTITUTE OF CHEMICAL ENGINEERS Vol.80 No.-

<P><B>Abstract</B></P> <P>Herein we developed a nanocomposite of MnO<SUB>2</SUB> and multiwall carbon nanotubes (MWCNTs) deposited on a stainless-steel mesh substrate using a simple and scalable chemical approach to greatly expand the capacitive performance of MnO<SUB>2</SUB>-based electrodes. Electrochemical investigations of the chemically prepared MWCNTs/MnO<SUB>2</SUB> nanocomposite showed that it has high specific capacitance (614 F/g), high specific energy (85.3 Wh/kg), and high stability over 2500 cycles. The enhanced capacitive performance of the MWCNTs/MnO<SUB>2</SUB> nanocomposite was analyzed by calculating the surface-controlled and diffusion-controlled charge components. A symmetric solid-state supercapacitor using a MWCNTs/MnO<SUB>2</SUB> nanocomposite electrode and polyvinyl alcohol (PVA)-Na<SUB>2</SUB>SO<SUB>4</SUB> gel electrolyte achieved a cell voltage of 1.0 V and a maximum specific capacitance of 204 F/g with an energy density of 28.33 Wh/kg. Furthermore, the assembled symmetric solid-state supercapacitor achieved coulombic efficiency of 99.04%. The excellent electrochemical features of the MWCNTs/MnO<SUB>2</SUB> nanocomposite electrode make it a promising material for application in future capacitor-based energy storage systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MWCNTs/MnO<SUB>2</SUB> nanocomposite on stainless steel mesh electrode was prepared by electrodeposition. </LI> <LI> The integrated MWCNTs/MnO<SUB>2</SUB> nanocomposite electrode delivers extraordinary electrochemical characteristics. </LI> <LI> Symmetric solid-state supercapacitor based on MWCNTs/MnO<SUB>2</SUB> nanocomposite electrode was successfully assembled. </LI> <LI> The assembled symmetric solid-state supercapacitor exhibits high energy density of 28.33 Wh/kg. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Fig. (a) shows the representative SEM image of MWCNT/MnO<SUB>2</SUB> nanocomposites with (b) the Ragone plot of the symmetric flexible solid-state supercapacitor designed in this study, in comparison with others reported in the literature.</P> <P>[DISPLAY OMISSION]</P>

Direct growth of FeCo2O4 nanowire arrays on flexible stainless steel mesh for high-performance asymmetric supercapacitor

Chodankar, Nilesh R,Dubal, Deepak P,Kwon, Yongchai,Kim, Do-Heyoung Nature Publishing Group 2017 NPG Asia Materials Vol.9 No.8

<P>Currently, one-dimensional nanostructured binary metal oxides attract a great attention in supercapacitors (SCs) application due to their rapid charge transportation. In this respect, different nanostructures of FeCo2O4 are designed by simply tuning the reaction temperature in hydrothermal synthesis. These nanostructures are directly grown on flexible stainless steel mesh and further applied as binder-free electrodes for SCs. The systematic study is carried out to confirm the relation between surface characteristics and electrochemical properties of FeCo2O4 thin film. Among different nanostructures, FeCo2O4 nanowire arrays exhibit hierarchical mesoporous structure and demonstrate good surface properties including high surface area and appropriate pore volume. As a consequence, relatively high specific capacitance of 1963 F g(-1) is obtained for the FeCo2O4 nanowire electrode. Further, asymmetric SC is fabricated using nanowired-FeCo2O4 and nanoparticulated-MnO2 thin films as negative and positive electrodes with neutral Na2SO4 electrolyte. Impressively, the MnO2//FeCo2O4 cell could be successfully cycled in a wide voltage window of 2.0 V, which can achieve a specific capacitance of 218 F g(-1) and energy density of 43 Wh kg(-1). In addition, the SCs exhibit improved capacitance with cycling, which is attributed to opening of micro-pores occurred by frequent ion transport.</P>

Rapid preparation of nickel fluoride motif via solution-free plasma route for high-energy aqueous hybrid supercapacitor

( Nilesh R. Chodankar ),박용현,한영규,허윤석 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.1

For the sake of highly efficient hybrid supercapacitors, potentiodynamic polarization assisted phosphorus-including amorphous trimetal hydroxide nanofibers

김관우,( Nilesh Chodankar ),( Ganji Seeta Rama Raju ),박범준,한영규,허윤석 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Due to their high capacity, nickel-cobalt-based cathode materials have attracted significant attention as potential components of hybrid solid-state supercapacitors. However, their poor cycling stability and low rate capability have impeded their implementation. In the present study, a single-step, binder-free potentiodynamic polarization approach is presented for the preparation of battery-type phosphorus-containing amorphous trimetal nickel-ruthenium-cobalt hydroxide nanofibers on Ni foam for use in high-energy, stable HSSCs. The phosphate dopant and the trimetal-rich electrode surface increase the intrinsic electron conductivity and redox activity and generate a large number of active defects. As a consequence, a P@NRC-OH electrode exhibited enhanced energy storage properties in terms of specific capacity, cycling durability, and rate capability.

Towards flexible solid-state supercapacitors for smart and wearable electronics

Dubal, Deepak P.,Chodankar, Nilesh R.,Kim, Do-Heyoung,Gomez-Romero, Pedro The Royal Society of Chemistry 2018 Chemical Society reviews Vol.47 No.6

<P>Flexible solid-state supercapacitors (FSSCs) are frontrunners in energy storage device technology and have attracted extensive attention owing to recent significant breakthroughs in modern wearable electronics. In this study, we review the state-of-the-art advancements in FSSCs to provide new insights on mechanisms, emerging electrode materials, flexible gel electrolytes and novel cell designs. The review begins with a brief introduction on the fundamental understanding of charge storage mechanisms based on the structural properties of electrode materials. The next sections briefly summarise the latest progress in flexible electrodes (<I>i.e.</I>, freestanding and substrate-supported, including textile, paper, metal foil/wire and polymer-based substrates) and flexible gel electrolytes (<I>i.e.</I>, aqueous, organic, ionic liquids and redox-active gels). Subsequently, a comprehensive summary of FSSC cell designs introduces some emerging electrode materials, including MXenes, metal nitrides, metal-organic frameworks (MOFs), polyoxometalates (POMs) and black phosphorus. Some potential practical applications, such as the development of piezoelectric, photo-, shape-memory, self-healing, electrochromic and integrated sensor-supercapacitors are also discussed. The final section highlights current challenges and future perspectives on research in this thriving field.</P>

Rationally Designed Phosphorous-containing Amorphous Ruthenium-Cobalt Hydroxide Nanofibers as an Advanced Cathode Material for High-Energy Hybrid Solid-State Supercapacitor

박범준,( Nilesh R. Chodankar ),허윤석,한영규 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

In present work, P doped RC-OH (P@RC-OH) nanofibers has been directly prepared over three dimensional (3D) highly conducting nickel (Ni) foam substrate by the single-step room temperature potentiodynamic polarization method for high energy and stable solid-state hybrid SCs. As a result, the prepared P@RC-OH electrode shows the excellent specific capacity of 262.3 mA h/g at scan rate of 100 mV/s which is quite higher than the other samples. Moreover, the P@RC-OH electrode shows the excellent cycling stability over 20000 cycles by maintain the 90 % of initial capacity. The assembled quasi-solid-state hybrid SCs with P@RC-OH as a positive and activated carbon (AC) as a negative electrode delivers ultrahigh specific capacity of 440 mA h/g at current density of 4 mA/cm2. Additionally, the assembled hybrid SCs exhibits the energy density of 90.02 Wh/kg at a power density of 1363 W/kg and remarkable cycling stability over 10000 charge-discharge cycles.

Aqueous asymmetric supercapacitor based on RuO₂-WO₃ electrodes

Ji, Su-Hyeon,Chodankar, Nilesh R.,Kim, Do-Heyoung Elsevier 2019 ELECTROCHIMICA ACTA Vol.325 No.-

<P><B>Abstract</B></P> <P>Designing high-energy asymmetric supercapacitors(SC) with appropriate positive and negative electrodes is urgently required to expand their practical applicability. The redox-active materials are beneficial for high-energy SC applications because of their multiple oxidation states and higher energy storage capacity than the traditional carbon-based materials. In this work, for the first time, we have designed and developed high-energy aqueous asymmetric SC by combining hexagonal WO<SUB>3</SUB> and hydrous RuO<SUB>2</SUB> in a single cell. Initially, the hexagonal (h) WO<SUB>3</SUB> and hydrous RuO<SUB>2</SUB> is directly prepared on three-dimensional conducting carbon cloth. Because of their higher electrical conductivity, nanoporous surface morphology, and redox activity, the prepared hydrous RuO<SUB>2</SUB> and WO<SUB>3</SUB> exhibit excellent electrochemical features in the positive and negative potential window, respectively, with aqueous H<SUB>2</SUB>SO<SUB>4</SUB> electrolyte. The assembled RuO<SUB>2</SUB>//h-WO<SUB>3</SUB> asymmetric SC device exhibits outstanding electrochemical performance in an operating voltage window of 1.6 V, excellent cycling stability of ∼171.75% (after 6500 cycles), and energy density of 1.25 Wh/cm<SUP>3</SUP> (16.92 W h/kg) at a power density of 40 W/cm<SUP>3</SUP> (540 W/kg). These results show that redox-active materials can prominently enhance the energy storage capacity of SC than the traditional carbon-based asymmetric SCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aqueous asymmetric SCs has been developed with hydrous RuO<SUB>2</SUB> and h-WO<SUB>3</SUB> as a positive and negative electrode. </LI> <LI> Binder-less approach has been developed to prepare hydrous RuO<SUB>2</SUB> and h-WO<SUB>3</SUB> over the flexible CC. </LI> <LI> RuO<SUB>2</SUB>//h-WO<SUB>3</SUB> aqueous asymmetric supercapacitor cell showed high energy density of 1.25 Wh/cm<SUP>3</SUP>. </LI> <LI> The device exhibited excellent long-term cycling stability (∼171.75% after 6500 cycles). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>In this paper, hydrous RuO<SUB>2</SUB> and h-WO<SUB>3</SUB> were directly grown on the carbon cloth for fabricating the aqueous asymmetric supercapacitor. The developed asymmetric supercapacitor shows excellent energy storing capacity with better rate capability and cycling stability.</P> <P>[DISPLAY OMISSION]</P>

Efficient and Stable Hybrid Supercapacitors with Solution-free Self-Assembled Growth of Ordered Cu₃P

황승규,( Nilesh R. Chodankar ),허윤석 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.-

An Aqueous High-Performance Hybrid Supercapacitor with Redox-active rGO/POM and MXene

황승규,( Nilesh R. Chodankar ),허윤석 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.-

Temperature dependent surface morphological modifications of hexagonal WO₃ thin films for high performance supercapacitor application

Shinde, Pragati A.,Lokhande, Abhishek C.,Chodankar, Nilesh R.,Patil, Amar M.,Kim, Jin H.,Lokhande, Chandrakant D. Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>In present article, temperature dependent surface morphological modification and its subsequent influence on electrochemical performance of hexagonal WO<SUB>3</SUB> (h-WO<SUB>3</SUB>) thin films has been investigated. The nanostructured h-WO<SUB>3</SUB> films are synthesized on carbon cloth substrate using simple hydrothermal method. It is observed that h-WO<SUB>3</SUB> thin films prepared at temperature of 413, 433 and 453K display nanogranule-like, nanoplate-like and nanorod-like suface morphology. The X-ray diffraction study discloses the prominent orientation along (001) and (200) planes which reveals the preferential growth direction of h-WO<SUB>3</SUB> along c and a-axis, respectively. The h-WO<SUB>3</SUB> film prepared at 453K shows good surface area, pore volume and uniform pore size distribution. The electrochemical measurements exhibit high specific capacitance of 694Fg<SUP>−1</SUP>, energy density of 25 Wh Kg<SUP>−1</SUP> and long term cycling performance (87 % capacitance retention after 2,000 cycles) for h-WO<SUB>3</SUB> thin film. The results indicate that h-WO<SUB>3</SUB> nanorods could be a promising electrode material for high performance energy storage devices.</P>