Maximizing volumetric energy density of all-graphene-oxide-supercapacitors and their potential applications for energy harvest

Kim, Hyuk Joon,Lee, Seul-Yi,Sinh, Le Hoang,Yeo, Chang Su,Son, Yeong Rae,Cho, Kang Rae,Song, YoonKyu,Ju, Sanghyun,Shin, Min Kyoon,Park, Soo-Jin,Park, SangYoon Elsevier 2017 Journal of Power Sources Vol.346 No.-

<P><B>Abstract</B></P> <P>Graphene has attracted widespread attention for supercapacitor applications thank to their excellent conductivity, mechanical flexibility, chemical stability and extremely high specific surface area. Here, all-graphene-oxide-supercapacitors were developed from two reduced graphene oxide (rGO) films as electrodes and one graphene oxide (GO) film as separator. The supercapacitors were then treated with 4M sulfuric acid at temperatures around 80 °C. By this treatment, the sulfuric acid molecules were physically intercalated into both rGO and GO films, which were confirmed by significant decrease intensity of characteristic peaks of sulfuric acid in Raman spectra. These sulfuric-acid-intercalated GO films can function as both quasi-solid-state electrolytes and separators. The average capacitance values measured at 100 mV s<SUP>−1</SUP> of the thermally wetted supercapacitor at 84 °C is improved 93.7 times higher than that of the as-prepared all-graphene-oxide-supercapacitor. The maximum capacitance of 266 F cm<SUP>−3</SUP> is obtained at scan rate 10 mV s<SUP>−1</SUP> for the thermally wetted supercapacitor at 84 °C. To the best of our knowledge, this is the highest specific capacitance that has ever been reported for a graphene oxide-based supercapacitor. Importantly, being in a quasi-solid-state, the energy storage performance of supercapacitors are persistent over several thousand cycles, making it very much unlike other carbon-based supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Quasi-solid-state all-graphene-oxide-supercapacitors were developed for the first time. </LI> <LI> Thermal wetting of the supercapacitors with H<SUB>2</SUB>SO<SUB>4</SUB> around 80 °C produces quasi-solid-state. </LI> <LI> A large volumetric capacitance of 266 F cm<SUP>−3</SUP> at a scan rate of 10 mV s<SUP>−1</SUP>. </LI> <LI> Energy storage performances of the supercapacitors are persistent over several thousand cycles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Improved performances of hybrid supercapacitors using granule Li₄Ti₅O₁₂/activated carbon composite anode

Lee, Seung-Hwan,Kim, Jong-Myon Elsevier 2018 Materials letters Vol.228 No.-

<P><B>Abstract</B></P> <P>Hybrid energy storage devices have been studied with combining the high energy of lithium ion batteries and high power and long life of supercapacitor in a single system. We successfully fabricated hybrid supercapacitors using granule Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>/activated carbon anode and activated carbon cathode for high electrochemical performances. The hybrid supercapacitors deliver a high capacity (63 F g<SUP>−1</SUP>) as well as a superior rate capability (81.9% retention from 0.5 to 5 A g<SUP>−1</SUP>) and a cycling stability (92.8% retention after 7000 cycles at 3 A g<SUP>−1</SUP>). This is related to a small internal resistance value. Therefore, hybrid supercapacitors based on LTO/AC and AC electrodes are a promising and innovative solution for high performance hybrid supercapacitor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>/activated carbon composite anode is prepared. </LI> <LI> Hybrid supercapacitors deliver a high capacity of 63 F g<SUP>−1</SUP> at 0.5 A g<SUP>−1</SUP>. </LI> <LI> Hybrid supercapacitors show a superior rate capability of 81.9% at 5 A g<SUP>−1</SUP>. </LI> <LI> Hybrid supercapacitors show a retention of 92.8% after 7000 cycles at 3 A g<SUP>−1</SUP>. </LI> </UL> </P>

Metal-organic frameworks and their composites as efficient electrodes for supercapacitor applications

Sundriyal, Shashank,Kaur, Harmeet,Bhardwaj, Sanjeev Kumar,Mishra, Sunita,Kim, Ki-Hyun,Deep, Akash Elsevier 2018 Coordination chemistry reviews Vol.369 No.-

<P><B>Abstract</B></P> <P>Metal-organic frameworks (MOFs) belong to a novel class of materials with several advantages (e.g., ultrahigh porosity, tunable pore size distribution, convenience of synthesis, and structural tailor-ability). However, the insulating nature of MOFs is often recognized as a limiting factor in the extension of their applications, especially in electronic fields. In light of such limitations, various functional or conductive materials have been mixed/intercalated with MOFs to improve their potential for such applications (e.g., rechargeable batteries, optoelectronics, and supercapacitors). Lately, many of these composite materials have been recognized as next-generation electrodes for the development of efficient supercapacitors. In this review article, we have critically reviewed the recent advancements in supercapacitor applications of MOFs and their derived composite structures. Further, we have also discussed the application of various categories of electrolytes (e.g., aqueous, organic, ionic liquids, solid-state, and redox electrolytes) and their impacts on the development of MOF-based supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> State of the art information on the applications of MOF-based supercapacitor is explored. </LI> <LI> Recent advances in MOF-based supercapacitor applications have also been discussed. </LI> <LI> The role of electrolytes in the MOF-electrodes for supercapacitors has been discussed. </LI> <LI> Performance of MOF-composites is reviewed in terms of important supercapacitor parameters. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Punched H₂Ti₁₂O₂₅ anode and activated carbon cathode for high energy/high power hybrid supercapacitors

Lee, Seung-Hwan,Kim, Jong-Myon Elsevier 2018 ENERGY Vol.150 No.-

<P><B>Abstract</B></P> <P>Hybrid supercapacitors composed of a punched H<SUB>2</SUB>Ti<SUB>12</SUB>O<SUB>25</SUB> (P-HTO) anode and an activated carbon (AC) cathode were designed for high energy/power hybrid supercapacitors. The hybrid supercapacitors delivered a high reversible capacitance of 72.1 F/g at a current density of 0.5 A/g, and 95.3% of the capacity was retained after 20000 cycles. Furthermore, the hybrid supercapacitors using P-HTO anode and AC cathode (P-HTO/AC) electrodes demonstrated energy densities of 28.4–86.7 Wh/kg and power densities of 226.7–12618.5 W/kg, which can meet the requirement of hybrid electric vehicle (HEV) and plug-in hybrid electric vehicle (PHEV). The performances of the hybrid supercapacitors using P-HTO/AC were explained in terms of the synergistic effect of high-power P-HTO and high-energy AC. Therefore, we concluded that the P-HTO/AC composition will be useful in next-generation hybrid supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hybrid supercapacitors were fabricated with punched H<SUB>2</SUB>Ti<SUB>12</SUB>O<SUB>25</SUB> anode. </LI> <LI> Initial discharge capacitance of punched H<SUB>2</SUB>Ti<SUB>12</SUB>O<SUB>25</SUB> was 72.1 F/g. </LI> <LI> Capacitance retention of punched H<SUB>2</SUB>Ti<SUB>12</SUB>O<SUB>25</SUB> was 95.3% after 20000 cycles. </LI> <LI> Power densities of punched H<SUB>2</SUB>Ti<SUB>12</SUB>O<SUB>25</SUB> were 226.7–12618.5 W/kg. </LI> <LI> Energy densities of punched H<SUB>2</SUB>Ti<SUB>12</SUB>O<SUB>25</SUB> were 28.4–86.7 Wh/kg. </LI> </UL> </P>

Bimetallic <i>copper cobalt selenide</i> nanowire-anchored woven carbon fiber-based structural supercapacitors

Deka, Biplab K.,Hazarika, Ankita,Kim, Jisoo,Kim, Namhun,Jeong, Hoon Eui,Park, Young-Bin,Park, Hyung Wook Elsevier 2019 Chemical Engineering Journal Vol.355 No.-

<P><B>Abstract</B></P> <P>Structural supercapacitors provide a variety of opportunities for woven carbon fibers in portable electronics, hybrid automobiles and aerospace applications. We describe herein the synthesis of bimetallic Cu-Co selenide nanowires based on woven carbon fibers, and their use as electrodes in supercapacitors. Woven Kevlar fiber is used as separator for the electrodes and a polyester resin with an ionic liquid and lithium salt is used as solid polymer electrolyte. The supercapacitors exhibit efficient energy storage and significant enhancements in mechanical strength (89.38%) and modulus (70.41%) over those of bare woven carbon fiber base supercapacitors. The specific capacitance of these supercapacitors increases from 0.197 F g<SUP>−1</SUP> to 28.63 F g<SUP>−1</SUP> after the growth of nanowires, with accordingly high energy density (191.64 mW h kg<SUP>−1</SUP>) and power density (36.65 W kg<SUP>−1</SUP>). In situ mechano-electrochemical tests of these supercapacitors yield excellent capacitance retention (77.3%) at the mechanical failure point (481.29 MPa).</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>CuCoSe</I> nanowire grown WCF based structural supercapacitor was developed. </LI> <LI> Device exhibited high electrochemical performance with brilliant cyclicability. </LI> <LI> Polyester resin based electrolyte was developed with ionic liquid and Li-salt. </LI> <LI> Excellent energy (191.64 mWhk g<SUP>−1</SUP>) and power densities (36.65 W kg<SUP>−1</SUP>) achieved. </LI> <LI> At mechanical failure (481.29 MPa), 77.3% capacitance retention were recorded. </LI> </UL> </P>

유기계 슈퍼커패시터에서 도전재의 양이 전기화학적 특성에 미치는 영향

양인찬,이기훈,정지철,Yang, Inchan,Lee, Gihoon,Jung, Ji Chul 한국재료학회 2016 한국재료학회지 Vol.26 No.12

In this study, we intensively investigated the effect of conductive additive amount on electrochemical performance of organic supercapacitors. For this purpose, we assembled coin-type organic supercapacitor cells with a variation of conductive additive(carbon black) amount; carbon aerogel and polyvinylidene fluoride were employed as active material and binder, respectively. Carbon aerogel, which is a highly mesoporous and ultralight material, was prepared via pyrolysis of resorcinol-formaldehyde gels synthesized from polycondensation of two starting materials using sodium carbonate as the base catalyst. Successful formation of carbon aerogel was well confirmed by Fourier-transform infrared spectroscopy and $N_2$ adsorption-desorption analysis. Electrochemical performances of the assembled organic supercapacitor cells were evaluated by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements. Amount of conductive additive was found to strongly affect the charge transfer resistance of the supercapacitor electrodes, leading to a different optimal amount of conductive additive in organic supercapacitor electrodes depending on the applied charge-discharge rate. A high-rate charge-discharge process required a relatively high amount of conductive additive. Through this work, we came to conclude that determining the optimal amount of conductive additive in developing an efficient organic supercapacitor should include a significant consideration of supercapacitor end use, especially the rate employed for the charge-discharge process.

Symmetric supercapacitor: Sulphurized graphene and ionic liquid

Shaikh, Jasmin S.,Shaikh, Navajsharif S.,Kharade, Rohini,Beknalkar, Sonali A.,Patil, Jyoti V.,Suryawanshi, Mahesh P.,Kanjanaboos, Pongsakorn,Hong, Chang Kook,Kim, Jin Hyeok,Patil, Pramod S. Elsevier 2018 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.527 No.-

<P><B>Abstract</B></P> <P>Symmetric supercapacitor is advanced over simple supercapacitor device due to their stability over a large potential window and high energy density. Graphene is a desired candidate for supercapacitor application since it has a high surface area, good electronic conductivity and high electro chemical stability. There is a pragmatic use of ionic liquid electrolyte for supercapacitor due to its stability over a large potential window, good ionic conductivity and eco-friendly nature. For high performance supercapacitor, the interaction between ionic liquid electrolyte and graphene are crucial for better charge transportation. In respect of this, a three-dimensional (3D) nanoporous honeycomb shaped sulfur embedded graphene (S-graphene) has been synthesized by simple chemical method. Here, the fabrication of high performance symmetric supercapacitor is done by using S-graphene as an electrode and [BMIM-PF<SUB>6</SUB>] as an electrolyte. The particular architecture of S-graphene benefited to reduce the ion diffusion resistance, providing the large surface area for charge transportation and efficient charge storage. The S-graphene and ionic liquid-based symmetric supercapacitor device showed the large potential window of 3.2 V with high energy density 124 Wh kg<SUP>−1</SUP> at 0.2 A g<SUP>−1</SUP> constant applied current density. Furthermore, this device shows good cycling performance (stability) with a capacitive retention of 95% over 20,000 cycles at a higher current density of 2 A g<SUP>−1</SUP>.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

RF무선충전을 위한 슈퍼커패시터 충전특성 측정

손명식,Son, Myung Sik 한국반도체디스플레이기술학회 2021 반도체디스플레이기술학회지 Vol.20 No.3

In this paper, we studied the charging characteristics of high-capacity supercapacitor with high current for RF wireless charging system for smart phone charging. The dc output of the RF-DC receiver is connected to supercapacitor after which is connected to DC-DC converter for charging a smart phone. This configuration stably supplies voltage and current for charging it. Studies show that the higher charging current use, the rapidly shorter the charging time of supercapacitor is. The currents of 2A, 10A and 27A were used for charging supercapacitors. The charging time was measured for 3000F, 6000F, 12000F supercapacitors which is parallelly connected with 3000F supercapacitors.

Ni-Co hydroxide nanoneedles embedded in graphene hydrogel as a binder-free electrode for high-performance asymmetric supercapacitor

Hwang, Minsik,Kang, Jeongmin,Seong, Kwang-dong,Kim, Dae Kyom,Jin, Xuanzhen,Antink, Wytse Hooch,Lee, Chaedong,Piao, Yuanzhe Elsevier 2018 ELECTROCHIMICA ACTA Vol.270 No.-

<P><B>Abstract</B></P> <P>Ni-Co hydroxide nanoneedles embedded in graphene hydrogel are fabricated using an efficient two-step method and further explored as a binder-free electrode for high-performance asymmetric supercapacitors. First, freestanding graphene hydrogel is prepared via reduction in a mild condition. Second, Ni-Co hydroxide nanoneedles embedded in graphene hydrogel are obtained using a simple hydrothermal method. The existence of many hydrophilic functional groups in graphene hydrogel results in the generation of well-dispersed Ni-Co hydroxide nanoneedles throughout the graphene nanosheet. Moreover, the freestanding property of graphene hydrogel allows it to be used as a binder-free electrode, which can improve the energy density of the asymmetric supercapacitor without inhibiting its high power capabilities. The composite shows an excellent capacity of 544 C g<SUP>−1</SUP> at 2 A g<SUP>−1</SUP> in a three-electrode system. Moreover, the binder-free asymmetric supercapacitor achieves excellent performance with an energy density of 32.74 Wh kg<SUP>−1</SUP> at a power density of 320 W kg<SUP>−1</SUP> and good cycling stability with 85% capacitance retention at a current density of 10 mA cm<SUP>−2</SUP> after 5000 cycles. Therefore, the Ni-Co hydroxide nanoneedles embedded in graphene hydrogel have immense potential as electrochemically active materials for the development of high-performance supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ni-Co hydroxide nanoneedles embedded in 3D graphene hydrogel were prepared by an efficient two-step method. </LI> <LI> The nanocomposite of Ni-Co hydroxide/graphene hydrogel was used as a binder-free supercapacitor electrode. </LI> <LI> The nanocomposite shows a high capacity of 544 C g<SUP>−1</SUP> at 2 A g<SUP>−1</SUP> in a three-electrode system. </LI> <LI> The asymmetric supercapacitor prepared by using the nanocomposite shows excellent power/energy density and cycling stability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The paper reported the Ni-Co hydroxide nanoneedles embedded in graphene hydrogel using facile two-step method. The asymmetric supercapacitor prepared by using the nanocomposite shows excellent energy density and cycling stability.</P> <P>[DISPLAY OMISSION]</P>

A 10 years-developmental study on conducting polymers composites for supercapacitors electrodes: A review for extensive data interpretation

Ahmed El-Shahat Etman,Asmaa Mohammed Ibrahim,Fatma Al-Zahraa Mostafa Darwish,Khaled Faisal Qasim 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

Supercapacitors are one of the most promising technologies to meet the requirements of human sustainabledevelopment, due to their benefits such as high capacitance and rate capability, long cycle life, andlow processing cost. Electrode materials play a decisive role in the performance of supercapacitors, that’swhy many types of research on electrode materials are critical to supercapacitors. As we go forwardtoward highly flexible and bendable electronics. Conducting polymer (CP)-based materials are promisingmaterials in supercapacitors because of their unique advantages including good conductivity, flexibility,relatively cheap, easy synthesis, and so on. This review summarizes recent research progress of CPs (includingpolypyrrole (PPy), polyaniline (PANI), and polythiophene (PTh)), the CP-based composites forsupercapacitors in purpose and concentrating composites’ effect on supercapacitive parameters, besidediffusion mechanism with the calculations of supercapcitive parameters in every technique. Eventually, we give a brief outline of the development directions of CP-based supercapacitors with suggestionsfor the future of supercapacitors based on the last decade’s research.