synthesizing-gel-polymer-electrolyte-for-supercapacitors-assembling

Synthesizing a Gel Polymer Electrolyte for Supercapacitors, Assembling a Supercapacitor Using a Coin Cell, and Measuring Gel Electrolyte Performance

Supercapacitors (SC) have attracted attention as energy storage devices due to their high density and long cycle performance. SCs used in devices ...

elaborate-control-inkjet-printer-for-fabrication-chip-based

Elaborate Control of Inkjet Printer for Fabrication of Chip-based Supercapacitors

There are tremendous efforts in various fields to apply the inkjet printing method for the fabrication of wearable devices, displays, and energy storage ...

evaluating-electrochemical-properties-supercapacitors-using-three

Evaluating the Electrochemical Properties of Supercapacitors using the Three-Electrode System

The three-electrode system is a basic and general analytical platform for investigating the electrochemical performance and characteristics of energy ...

chung-ang university

Chung-Ang University

Since the beginning of the 2000s, globalization has accelerated because of the development of transportation systems that allow for human and material exchanges throughout the world. However, this globalization has brought with it the rise of various pathogenic viral agents, such as Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), Zika virus, and Dengue virus. In particular, avian influenza virus (AIV) is highly infectious and causes economic, health, ethnical, and social problems to human beings, which has necessitated the development of an ultrasensitive and selective rapid-detection system of AIV. To prevent the damage associated with the spread of AIV, early detection and adequate treatment of AIV is key. There are traditional techniques that have been used to detect AIV in chickens, ducks, humans, and other living organisms. However, the development of a technique that allows for the more rapid diagnosis of AIV is still necessary. To achieve this goal, the present article reviews the use of an AIV biosensor employing nanobio hybrid materials to enhance the sensitivity and selectivity of the technique while also reducing the detection time and high-throughput process time. This review mainly focused on four techniques: the electrochemical detection system, electrical detection method, optical detection methods based on localized surface plasmon resonance, and fluorescence.

Recent Advances in AIV Biosensors Composed of Nanobio Hybrid Material.

In the present study, we fabricated a dual-mode cardiac troponin I (cTnI) biosensor comprised of multi-functional DNA (MF-DNA) on Au nanocrystal (AuNC) using an electrochemical method (EC) and a localized surface plasmon resonance (LSPR) method. To construct a cTnI bioprobe, a DNA 3 way-junction (3WJ) was prepared to introduce multi-functionality. Each DNA 3WJ arm was modified to possess a recognition region (Troponin I detection aptamer), an EC-LSPR signal generation region (methylene blue: MB), and an anchoring region (Thiol group), respectively. After an annealing step, the multi-functional DNA 3WJ was assembled, and its configuration was confirmed by Native-TBM PAGE for subsequent use in biosensor construction. cTnI was also expressed and purified for use in biosensor experiments. To construct an EC-LSPR dual-mode biosensor, AuNCs were prepared on an indium-tin-oxide (ITO) substrate using an electrodeposition method. The prepared multi-functional (MF)-DNA was then immobilized onto AuNCs by covalent bonding. Field emission scanning electron microscope (FE-SEM) and atomic force microscopy (AFM) were used to analyze the surface morphology. LSPR and electrochemical impedance spectroscopy (EIS) experiments were performed to confirm the binding between the target and the bioprobe. The results indicated that cTnI could be effectively detected in the buffer solution and in diluted-human serum. Based on the results of these experiments, the loss on drying (LOD) was determined to be 1.0 pM in HEPES solution and 1.0 pM in 10% diluted human serum. Additionally, the selectivity assay was successfully tested using a number of different proteins. Taken together, the results of our study indicate that the proposed dual-mode biosensor is applicable for use in field-ready cTnI diagnosis systems for emergency situations.

Fabrication of Troponin I Biosensor Composed of Multi-Functional DNA Structure/Au Nanocrystal Using Electrochemical and Localized Surface Plasmon Resonance Dual-Detection Method.

Hg ions can accumulate in the natural environment and in organisms, where they cause damage to the central nervous system. Therefore, the detection of Hg ions is essential for monitoring environmental contamination and human health. Herein, we demonstrate a simple method for tuning chemosensor signal ratios that significantly increased chemosensor selectivity for Hg detection. Selectivity tuning was accomplished for chemosensors of the type (diphosphine)Pt(dmit), bearing the two different terminal groups 1,2-bis(diphenylphosphino)ethane (dppe) and 1,2-bis[bis(pentafluorophenyl)phosphino]ethane) (dfppe) due to the modulation of specific intermolecular interactions between the dmit ligand and Hg ion. The structure exhibited a large pseudo-Stokes shift, which was advantageous for the internal reference signal and for eliminating potential artifacts. Straightforward chain-end manipulation enabled the tuning of chemosensor properties without additional chemical alterations. Based on these findings, we propose a new platform for improving the selectivity and sensitivity of colorimetric cation sensors. The results of this study will facilitate the designing of organic materials whose certain properties can be enhanced through precise control of the materials' chemical hybridization by simple functional end-group manipulation.

Heteroleptic Pt(II)-dithiolene-based Colorimetric Chemosensors: Selectivity Control for Hg(II) Ion Sensing.

Planar and rigid conventional electronics are intrinsically incompatible with curvilinear and deformable devices. The recent development of organic and inorganic flexible and stretchable electronics enables the production of various applications, such as soft robots, flexible displays, wearable electronics, electronic skins, bendable phones, and implantable medical devices. To power these devices, persistent efforts have thus been expended to develop a flexible energy storage system that can be ideally deformed while maintaining its electrochemical performance. In this review, the enabling technologies of the electrochemical and mechanical performances of flexible devices are summarized. The investigations demonstrate the improvement of electrochemical performance via the adoption of new materials and alternative reactions. Moreover, the strategies used to develop novel materials and distinct design configurations are introduced in the following sections.

Free-Form and Deformable Energy Storage as a Forerunner to Next-Generation Smart Electronics.

Coffee is one of the largest agricultural products; however, the majority of the produced coffee is discarded as waste sludge by beverage manufacturers. Herein, we report the use of graphitic porous carbon materials that have been derived from waste coffee sludge for developing an energy storage electrode based on a hydrothermal recycling procedure. Waste coffee sludge is used as a carbonaceous precursor for energy storage due to its greater abundance, lower cost, and easier availability as compared to other carbon resources. The intrinsic fibrous structure of coffee sludge is based on cellulose and demonstrates enhanced ionic and electronic conductivities. The material is primarily composed of cellulose-based materials along with several heteroatoms; therefore, the waste sludge can be easily converted to functionalized carbon. The production of unique graphitic porous carbon by hydrothermal carbonization of coffee sludge is particularly attractive since it addresses waste handling issues, offers a cheaper recycling method, and reduces the requirement for landfills. Our investigations revealed that the graphitic porous carbon electrodes derived from coffee sludge provide a specific capacitance of 140 F g, with 97% retention of the charge storage capacity after 1500 cycles at current density of 0.3 A g.

Graphitic Porous Carbon Derived from Waste Coffee Sludge for Energy Storage.

Supercapacitors prepared by printing allow a simple manufacturing process, easy customization, high material efficiency and wide substrate compatibility. While printable active layers have been widely studied, printable electrolytes have not been thoroughly investigated despite their importance. A printable electrolyte should not only have high ionic conductivity, but also proper viscosity, small particle size and chemical stability. Here, gel-polymer electrolytes (GPE) that are compatible with printing were developed and their electrochemical performance was analyzed. Five GPE formulations based on various polymer-conductive substance combinations were investigated. Among them, GPE made of polyvinylidene difluoride (PVDF) polymer matrix and LiClO conductive substance exhibited the best electrochemical performance, with a gravimetric capacitance of 176.4 F/g and areal capacitance of 152.7 mF/cm at a potential scan rate of 10 mV/s. The in-depth study of the in-plane solid-state supercapacitors based on various printed GPEs suggests that printable electrolytes provide desirable attributes for high-performance printed energy devices such as supercapacitors, batteries, fuel cells and dye-sensitized solar cells.

Printable Gel Polymer Electrolytes for Solid-State Printed Supercapacitors.

The spread of wearable and flexible electronics devices has been accelerating in recent years for a wide range of applications. Development of an appropriate flexible power source to operate these flexible devices is a key challenge. Supercapacitors are attractive for powering portable lightweight consumer devices due to their long cycle stability, fast charge-discharge cycle, outstanding power density, wide operating temperatures and safety. Much effort has been devoted to ensure high mechanical and electrochemical stability upon bending, folding or stretching and to develop flexible electrodes, substrates and overall geometrically-flexible structures. Supercapacitors have attracted considerable attention and shown many applications on various scales. In this review, we focus on flexible structural design under six categories: paper-like, textile-like, wire-like, origami, biomimetics based design and micro-supercapacitors. Finally, we present our perspective of flexible supercapacitors and emphasize current technical difficulties to stimulate further research.

Methodologies for Fabricating Flexible Supercapacitors.

Value creation through waste recycling is important for a sustainable society and future. In particular, biomass, which is based on crops, is a great recyclable resource that can be converted into useful materials. Black tea is one of the most cultivated agricultural products in the world and is mostly discarded after brewing. Herein, we report the application of black tea waste biomass as electrode material for supercapacitors through the activation of biomass hydrochar under various conditions. Raw black tea was converted into hydrochar via a hydrothermal carbonization process and then activated with potassium hydroxide (KOH) to provide a large surface area and porous structure. The activation temperature and ratio of KOH were controlled to synthesize the optimal black tea carbon (BTC) with a large surface area and porosity suitable for use as electrode material. This method suggests a direction in which the enormous amount of biomass, which is simply discarded, can be utilized in the energy storage system. The synthesized optimal BTC has a large surface area of 1062 m and specific capacitance up to 200 F∙g at 1 mV∙s. Moreover, it has 98.8% retention of charge-discharge capacitance after 2000 cycles at the current density of 5 A∙g.

Recycling Black Tea Waste Biomass as Activated Porous Carbon for Long Life Cycle Supercapacitor Electrodes.

Despite its importance for the establishment of a carbon-neutral society, the electrochemical reduction of CO  to value-added products has not been commercialized yet because of its sluggish kinetics and low selectivity. The present work reports the fabrication of a low-crystalline trimetallic (AuCuIn) CO  electroreduction catalyst and demonstrates its high performance in a gaseous CO  electrolyzer. The high Faradaic efficiency (FE) of CO formation observed at a low overpotential in a half-cell test is ascribed to the controlled crystallinity and composition of this catalyst as well as to its faster charge transfer, downshifted d-band center, and low oxophilicity. The gaseous CO  electrolyzer with the optimal catalyst as the cathode exhibits superior cell performance with a high CO FE and production rate, outperforming state-of-the-art analogs. Thus, the obtained results pave the way to the commercialization of CO  electrolyzers and promote the establishment of a greener society.

Low-Crystalline AuCuIn Catalyst for Gaseous CO  Electrolyzer.

TiO offers several advantages over graphite as an anode material for Li-ion batteries (LIBs) but suffers from low electrical conductivity and Li-diffusion issues. Control over defect chemistry has proven to be an effective strategy to overcome these issues. However, defect engineering has primarily been focused on oxygen vacancies (V). The role of another intrinsic TiO vacancy [i.e., titanium vacancies (V)] with regard to the Li storage behavior of TiO has largely evaded attention. Hence, a comparison of V- and V-defective TiO can provide valuable insight into how these two types of defects affect Li storage behavior. To eliminate other factors that may also affect the Li storage behavior of TiO, we carefully devised synthesis protocols to prepare TiO with either V (n-TiO) or V (p-TiO). Both TiO materials were verified to have a very similar morphology, surface area, and crystal structure. Although V provided additional sites that improved the capacity at low C-rates, the benefit obtained from over-lithiation turned out to be detrimental to cycling stability. Unlike V, V could not serve as an additional lithium reservoir but could significantly improve the rate performance of TiO. More importantly, the presence of V prevented over-lithiation, significantly improving the cycling stability of TiO. We believe that these new insights could help guide the development of high-performance TiO for LIB applications.

Exploring the Effect of Cation Vacancies in TiO: Lithiation Behavior of n-Type and p-Type TiO.

We assemble a film of a phosphocholine-based lipid and a crystalline conjugated polymer using hydrophobic interactions between the alkyl tails of the lipid and alkyl side chains of the polymer, and demonstrated its selective gas adsorption properties and the polymer's improved light absorption properties. We show that a strong attractive interaction between the polar lipid heads and CO was responsible for 6 times more CO being adsorbed onto the assembly than N, and that with repeated CO adsorption and vacuuming procedures, the assembly structures of the lipid-polymer assembly were irreversibly changed, as demonstrated by  grazing-incidence X-ray diffraction during the gas adsorption and desorption. Despite the disruption of the lipid structure caused by adsorbed polar gas molecules on polar head groups, gas adsorption could promote orderly alkyl chain packing by inducing compressive strain, resulting in enhanced electron delocalization of conjugated backbones and bathochromic light absorption. The findings suggest that merging the structures of the crystalline functional polymer and lipid bilayer is a viable option for solar energy-converting systems that use conjugated polymers as a light harvester and the polar heads as CO-capturing sites.

Selective CO adsorption and bathochromic shift in a phosphocholine-based lipid and conjugated polymer assembly.

The increasing use of rapidly fluctuating renewable energy sources, such as sunlight, has necessitated the use of supercapacitors, which are a type of energy storage system with high power. Chemically exfoliated graphene oxide (GO) is a representative starting material in the fabrication of supercapacitor electrodes based on reduced GO (rGO). However, the restacking of rGO sheets driven by π-π stacking interactions leads to a significant decrease in the electrochemically active surface area, leading to a loss of energy density. Here, to effectively inhibit restacking and construct a three-dimensional wrinkled structure of rGO (3DWG), we propose an agarose gel-templating method that uses agarose gel as a soft and removable template. The 3DWG, prepared via the sequential steps of gelation, freeze-drying, and calcination, exhibits a macroporous 3D structure and 5.5-fold higher specific capacitance than that of rGO restacked without the agarose template. Further, we demonstrate a "gel-stamping" method to fabricate thin-line patterned 3DWG, which involves the gelation of the GO-agarose gel within micrometer-sized channels of a customized polydimethylsiloxane (PDMS) mold. As an easy and low-cost manufacturing process, the proposed agarose gel templating method could provide a promising strategy for the 3D structuring of rGO.

ArticleTotal : 3	Year
Publication title Cited by 1	2022
Publication title	2021
Publication title Cited by 2	2022

Article	Year
Recent Advances in AIV Biosensors Composed of Nanobio Hybrid Material. Micromachines\| PubMed ID: 30544883	2018
Fabrication of Troponin I Biosensor Composed of Multi-Functional DNA Structure/Au Nanocrystal Using Electrochemical and Localized Surface Plasmon Resonance Dual-Detection Method. Nanomaterials (Basel, Switzerland)\| PubMed ID: 31373309	2019
Heteroleptic Pt(II)-dithiolene-based Colorimetric Chemosensors: Selectivity Control for Hg(II) Ion Sensing. Materials (Basel, Switzerland)\| PubMed ID: 32204319	2020
Free-Form and Deformable Energy Storage as a Forerunner to Next-Generation Smart Electronics. Micromachines\| PubMed ID: 32224996	2020
Graphitic Porous Carbon Derived from Waste Coffee Sludge for Energy Storage. Materials (Basel, Switzerland)\| PubMed ID: 32911742	2020
Printable Gel Polymer Electrolytes for Solid-State Printed Supercapacitors. Materials (Basel, Switzerland)\| PubMed ID: 33435423	2021
Methodologies for Fabricating Flexible Supercapacitors. Micromachines\| PubMed ID: 33562424	2021
Recycling Black Tea Waste Biomass as Activated Porous Carbon for Long Life Cycle Supercapacitor Electrodes. Materials (Basel, Switzerland)\| PubMed ID: 34772115	2021
Low-Crystalline AuCuIn Catalyst for Gaseous CO Electrolyzer. Advanced science (Weinheim, Baden-Wurttemberg, Germany)\| PubMed ID: 35064768	2022
Exploring the Effect of Cation Vacancies in TiO: Lithiation Behavior of n-Type and p-Type TiO. ACS applied materials & interfaces\| PubMed ID: 35089708	2022
Selective CO adsorption and bathochromic shift in a phosphocholine-based lipid and conjugated polymer assembly. RSC advances\| PubMed ID: 35424813	2022
Agarose Gel-Templating Synthesis of a 3D Wrinkled Graphene Architecture for Enhanced Supercapacitor Performance. Micromachines\| PubMed ID: 35888929	2022

Inho Nam

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