Central Electrochemical Research Institute

Increasing demand for finding eco-friendly and everlasting energy sources is now totally depending on fuel cell technology. Though it is an eco-friendly way of producing energy for the urgent requirements, it needs to be improved to make it cheaper and more eco-friendly. Although there are several types of fuel cells, the hydrogen (H2) and oxygen (O2) fuel cell is the one with zero carbon emission and water as the only byproduct. However, supplying fuels in the purest form (at least the H2) is essential to ensure higher life cycles and less decay in cell efficiency. The current large-scale H2 production is largely dependent on steam reforming of fossil fuels, which generates CO2 along with H2 and the source of which is going to be depleted. As an alternate, electrolysis of water has been given greater attention than the steam reforming. The reasons are as follows: the very high purity of the H2 produced, the abundant source, no need for high-temperature, high-pressure reactors, and so on. In earlier days, noble metals such as Pt (cathode) and Ir and Ru (anode) were used for this purpose. However, there are problems in employing these metals, as they are noble and expensive. In this review, we elaborate how the group VIII 3d metal sulfide, selenide, and phosphide nanomaterials have arisen as abundant and cheaper electrode materials (catalysts) beyond the oxides and hydroxides of the same. We also highlight the evaluation perspective of such electrocatalysts toward water electrolysis in detail.

To avoid unnoticed errors made by researchers who are working in the area of nanostructured materials for water splitting, the correct and precise use of evaluation parameters is discussed in detail, stating their acceptability and validity.

Abstract The growth in the application of electronic devices across a broad spectrum of military, industrial, commercial and consumer sectors has created a new form of pollution known as noise or radio frequency interference (RFI) or electromagnetic radiation or electromagnetic interference (EMI) that can cause interference or malfunctioning of equipment. Therefore, there is a greater need for the effective shielding of components from its adverse effects. This review surveys the shielding materials like metals, conducting plastics and conducting polymers for the control of electromagnetic radiations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Functionalized multiwalled carbon nanotubes (CNTs) are coated with a 4-5 nm thin layer of V(2)O(5) by controlled hydrolysis of vanadium alkoxide. The resulting V(2)O(5)/CNT composite has been investigated for electrochemical activity with lithium ion, and the capacity value shows both faradaic and capacitive (nonfaradaic) contributions. At high rate (1 C), the capacitive behavior dominates the intercalation as 2/3 of the overall capacity value out of 2700 C/g is capacitive, while the remaining is due to Li-ion intercalation. These numbers are in agreement with the Trasatti plots and are corroborated by X-ray photoelectron spectroscopy (XPS) studies on the V(2)O(5)/CNTs electrode, which show 85% of vanadium in the +4 oxidation state after the discharge at 1 C rate. The cumulative high-capacity value is attributed to the unique property of the nano V(2)O(5)/CNTs composite, which provides a short diffusion path for Li(+)-ions and an easy access to vanadium redox centers besides the high conductivity of CNTs. The composite architecture exhibits both high power density and high energy density, stressing the benefits of using carbon substrates to design high performance supercapacitor electrodes.

Electrocatalytic oxygen evolution reaction (OER) catalyzed by non-precious metals and their compounds in alkaline medium is an attractive area of energy research for the generation of hydrogen from water. The 3d transition metals, particularly, Ni and Co show better OER activity than others in alkaline medium. Ni and Co based oxygen-evolving catalysts (OECs) experience an enormous enhancement in the OER activity either by incidental or intentional Fe doping/incorporation. To account for this, different roles of Fe that it exerts when incorporated into these OECs are reported to be responsible. Unfortunately, the conclusions drawn in many related studies are often contradictory to one another. Important contradictory conclusions are: 1) a few studies claim Fe is the active site and Ni/Co are inactive while other studies claim Ni/Co and Fe act together in OER, 2) a few studies claim Fe3+ stays unoxidized while a few shows evidence for the existence of Fe4+, and 3) a few studies suggest Fe3+ is the faster site in Ni/Co OEC matrices for OER but fail to explain similar effects observed with other OER matrices. Many critical experimental and theoretical investigations have been made recently to reveal this magical Fe effect and the results of those studies are coherently presented here with critical discussion. This review is presented as it is inevitable to know the critical roles of Fe effect in Ni/Co based OECs to succeed in energy efficient hydrogen generation in alkaline medium.

Carbon materials were synthesized from banana fibers by treating the fibers with pore-forming substances such as ZnCl2 and KOH with an intention to improve the surface area and their electrochemical performance as electrical double-layer capacitor electrodes. The performance of these materials was studied in a neutral electrolyte for the first time. There has been a substantive increase in the specific surface area of the treated carbon material because of the effective pore generations. The structural and surface properties of the prepared carbon materials were studied using scanning electron microscopy and N2 adsorption/desorption studies. The surface area of the 10% ZnCl2 treated sample was found to be 1097 m2/g. The electrochemical properties of untreated and porogen treated carbons were evaluated by using cyclic voltammetry and galvanostatic charge−discharge studies, and the specific capacitance as high as 74 F/g in 1 M Na2SO4 neutral electrolyte was obtained for 10% ZnCl2 treated carbon as determined by constant current charge−discharge studies. The system showed excellent cyclability with a Coulombic efficiency of ∼88% at a high current density of 500 mA/g for 500 cycles. The electrochemical performance of the high surface area carbon in the neutral electrolyte medium is significantly high, and the reasons are discussed.

Artificial intelligence (AI) is a modern approach based on computer science that develops programs and algorithms to make devices intelligent and efficient for performing tasks that usually require skilled human intelligence. AI involves various subsets, including machine learning (ML), deep learning (DL), conventional neural networks, fuzzy logic, and speech recognition, with unique capabilities and functionalities that can improve the performances of modern medical sciences. Such intelligent systems simplify human intervention in clinical diagnosis, medical imaging, and decision-making ability. In the same era, the Internet of Medical Things (IoMT) emerges as a next-generation bio-analytical tool that combines network-linked biomedical devices with a software application for advancing human health. In this review, we discuss the importance of AI in improving the capabilities of IoMT and point-of-care (POC) devices used in advanced healthcare sectors such as cardiac measurement, cancer diagnosis, and diabetes management. The role of AI in supporting advanced robotic surgeries developed for advanced biomedical applications is also discussed in this article. The position and importance of AI in improving the functionality, detection accuracy, decision-making ability of IoMT devices, and evaluation of associated risks assessment is discussed carefully and critically in this review. This review also encompasses the technological and engineering challenges and prospects for AI-based cloud-integrated personalized IoMT devices for designing efficient POC biomedical systems suitable for next-generation intelligent healthcare.

A layered phase, NaNi1/3Mn1/3Co1/3O2 (NaNMC), isostructural to NaCoO2 has been synthesized. Stoichiometric NaNMC crystallizes in a rhombohedral R3̅m space group where Na is in an octahedral environment (O3-Type). Galvanostatic cycling on NaNMC vs Na cell indicated a reversible intercalation of 0.5 Na, leading to a capacity of 120 mAh·g–1 in the voltage range of 2–3.75 V and indicating its possible application in Na-ion batteries. The electrochemically driven Na insertion/deinsertion in NaNMC is associated with several phase transitions and solid solution regimes which are studied by in situ X-ray diffraction. Sodium deinsertion in NaxNMC resulted in sequential phase transitions composed of biphasic and monophasic domains. The composition driven structural evolution in NaxNMC follows the sequence O3 ⇒ O1 ⇒ P3 ⇒ P1 phases with an increased ‘c’ parameter, while the ‘a’ parameter remains almost unchanged.

ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTDo the Evaluation Parameters Reflect Intrinsic Activity of Electrocatalysts in Electrochemical Water Splitting?Sengeni Anantharaj*Sengeni AnantharajAcademy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradhesh, IndiaMaterials Electrochemistry Division (MED), CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi 630006, Tamil Nadu, India*E-mail: [email protected] and [email protected]More by Sengeni Anantharajhttp://orcid.org/0000-0002-3265-2455 and Subrata Kundu*Subrata KunduAcademy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, Uttar Pradhesh, IndiaMaterials Electrochemistry Division (MED), CSIR-Central Electrochemical Research Institute (CECRI), Karaikudi 630006, Tamil Nadu, India*E-mail: [email protected] and [email protected]More by Subrata Kunduhttp://orcid.org/0000-0002-1992-9659Cite this: ACS Energy Lett. 2019, 4, 6, 1260–1264Publication Date (Web):May 10, 2019Publication History Received30 March 2019Accepted3 May 2019Published online10 May 2019Published inissue 14 June 2019https://pubs.acs.org/doi/10.1021/acsenergylett.9b00686https://doi.org/10.1021/acsenergylett.9b00686article-commentaryACS PublicationsCopyright © 2019 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views16737Altmetric-Citations323LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (786 KB) Get e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Catalysts,Electrical properties,Electrocatalysts,Electrodes,Radiology Get e-Alerts

The permeation of electrolytic hydrogen in Armco iron membranes has been investigated by the electrochemical technique described elsewhere. In purified solutions it has been found that the permeation rate follows the equations previously derived. This rate is inversely proportional to the thickness and to the surface coverage with atomic hydrogen θ. The intercept of the plot of reciprocal of the permeation rate against the thickness varies inversely as the coverage as also predicted by the equation. Anomalies in the thickness dependence often reported in the literature have been traced to the adsorption of impurities and to redeposited iron, which then limit the over‐all permeation rate. The variation of permeation with cathodic overpotential has been determined. It is found that at moderate overpotentials indicating a slow discharge rate‐determining step followed by Tafel recombination. At higher overpotentials , indicating a constant coverage brought about by a transition to electrochemical desorption. In confirmation of this mechanism attempts have been made to determine the pseudocapacitance of the electrode system by galvanostatic cathodic transients. The results show the complete absence of pseudocapacity in acid solutions, thus proving that discharge of hydrogen ions is the rate‐determining step.

This review describes recent developments relating to the synthesis of viologen-based electrochromes with co-redox species and their ECD performance.

Electrochemical capacitors are electrochemical devices with fast and highly reversible charge-storage and discharge capabilities. The devices are attractive for energy storage particularly in applications involving high-power requirements. Electrochemical capacitors employ two electrodes and an aqueous or a non-aqueous electrolyte, either in liquid or solid form; the latter provides the advantages of compactness, reliability, freedom from leakage of any liquid component and a large operating potential-window. One of the classes of solid electrolytes used in capacitors is polymer-based and they generally consist of dry solid-polymer electrolytes or gel-polymer electrolyte or composite-polymer electrolytes. Dry solid-polymer electrolytes suffer from poor ionic-conductivity values, between 10−8 and 10−7 S cm−1 under ambient conditions, but are safer than gel-polymer electrolytes that exhibit high conductivity of ca. 10−3 S cm−1 under ambient conditions. The aforesaid polymer-based electrolytes have the advantages of a wide potential window of ca. 4 V and hence can provide high energy-density. Gel-polymer electrolytes are generally prepared using organic solvents that are environmentally malignant. Hence, replacement of organic solvents with water in gel-polymer electrolytes is desirable which also minimizes the device cost substantially. The water containing gel-polymer electrolytes, called hydrogel-polymer electrolytes, are, however, limited by a low operating potential-window of only about 1.23 V. This article reviews salient features of electrochemical capacitors employing hydrogel-polymer electrolytes.

Green luminescent, graphene quantum dots (GQDs) with a uniform size of 3, 5, and 8.2(±0.3) nm in diameter were prepared electrochemically from MWCNTs in propylene carbonate by using LiClO(4) at 90 °C, whereas similar particles of 23(±2) nm were obtained at 30 °C under identical conditions. Both these sets of GQDs displayed a remarkable quantum efficiency of 6.3 and 5.1%, respectively. This method offers a novel strategy to synthesise size-tunable GQDs as evidenced by multiple characterisation techniques like transmission and scanning electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray diffraction (XRD). Photoluminescence of these GQDs can be tailored by size variation through a systematic change in key process parameters, like diameter of carbon nanotube, electric field, concentration of supporting electrolyte and temperature. GQDs are promising candidates for a variety of applications, such as biomarkers, nanoelectronic devices and chemosensors due to their unique features, like high photostability, biocompatibility, nontoxicity and tunable solubility in water.

Biomass-derived activated carbon materials were prepared by a two-step synthesis via carbonization followed by KOH activation of rice straw at 600 °C in an argon atmosphere. The formation of disordered micro- and mesopores on carbon by KOH chemical activation and the high specific surface area of ∼1007 m2 g–1 were confirmed by N2 adsorption–desorption. Further, the scanning electron microscopic analysis revealed the formation of disordered pores over the carbon surface, and the transmission electron microscopic analysis confirmed the formation and aggregation of ultrafine carbon nanoparticles of ∼5 nm in size after the carbonization and activation processes. The three-electrode cell in aqueous electrolyte shows high specific capacitance of 332 F g–1, with high specific capacitance retention of 99% after 5000 cycles. The fabricated symmetric supercapacitor device in aqueous 1 M H2SO4 electrolyte showed a high specific capacitance of 156 F g–1, with a high energy density of 7.8 Wh kg–1. The symmetric device fabricated using 1-ethyl-3-methyl imidazolium tetrafluoroborate ([EMIM][BF4]) ionic liquid exhibited a cell voltage of 2.5 V and a specific capacitance of 80 F g–1, with a high energy density of 17.4 Wh kg–1. The observed electrochemical performance clearly indicates that activated carbon derived from rice straw could be used as a promising electrode material in a supercapacitor for electrochemical energy storage. The cheaper and readily available rice straw raw materials, simple chemical activation process, and high performance promise that the obtained carbon material is viable for commercial applications in supercapacitors.

Nanocrystalline Li4Ti5O12 (LTO) crystallizing in cubic spinel-phase has been synthesized by single-step- solution-combustion method in less than one minute. LTO particles thus synthesized are flaky and highly porous in nature with a surface area of 12 m2/g. Transmission electron micrographs indicate the primary particles to be agglomerated crystallites of varying size between 20 and 50 nm with a 3-dimensional interconnected porous network. During their galvanostatic charge-discharge at varying rates, LTO electrodes yield a capacity value close to the theoretical value of 175 mA h/g at C/2 rate. The electrodes also exhibit promising capacity retention with little capacity loss over 100 cycles at varying discharge rates together with attractive discharge-rate capabilities yielding capacity values of 140 mA h/g and 70 mA h/g at 10 and 100 C discharge rates, respectively. The ameliorated electrode-performance is ascribed to nano and highly porous morphology of the electrodes that provide short diffusion-paths for Li in conjunction with electrolyte percolation through the electrode pores ensuring a high flux of Li. © 2010 American Chemical Society.

Abstract 2D interfacial heterostructures have found an unassailable status in energy storage systems, particularly in supercapacitors citing the intriguing structural and electrochemical characteristics. Exactly a decade ago, MXene, a promising 2D transition metal carbide/nitride/carbonitride was found to possess excellent conductivity, hydrophilicity, laudable charge storage opportunities, and enriched surface functionalities conducive for supercapacitors with inherent challenging shortcomings. To substantially improve, assembled 2D/2D MXene heterostructures exhibit commendable performance backed by the fact of swift increase in research interest. In this review, state‐of‐the‐art research progress in material design and electrochemical performance of 2D/2D MXene heterostructures for supercapacitors are investigated. Discussion is initially on MXene fundamentals including synthesis and energy storage governing properties. Particularly, different preparation including electrostatic assembly, in situ growth, hydrothermal treatment, and objective specific strategies and its implications are elaborated. Especially, the electrochemical interface science, electrode–electrolyte interaction and ion/electron dynamics and synergistic enhancement of MXene/rGO, MXene/LDH, MXene/metal sulfides and timely investigations on other 2D MXene architectures are provided for its compatibility from solid‐state to microsupercapacitors for commerciality. To conclude, a well‐comprehended outlook, key challenges, and prospective research guidelines stretching from fundamental mechanism investigations to material and electrolyte optimizations are presented to encourage advanced 2D MXene architectures for future generation supercapacitors.

The production of electrical and electronic equipment (EEE) is one of the fastest growing global manufacturing activities. This development has resulted in an increase of waste electric and electronic equipment (WEEE). Rapid economic growth, coupled with urbanization and growing demand for consumer goods, has increased both the consumption of EEE and the production of WEEE, which can be a source of hazardous wastes that pose a risk to the environment and to sustainable economic growth. To address potential environmental problems that could stem from improper management of WEEE, many countries and organizations have drafted national legislation to improve the reuse, recycling and other forms of material recovery from WEEE to reduce the amount and types of materials disposed in landfills. Recycling of waste electric and electronic equipment is important not only to reduce the amount of waste requiring treatment, but also to promote the recovery of valuable materials. EEE is diverse and complex with respect to the materials and components used and waste streams from the manufacturing processes. Characterization of these wastes is of paramount importance for developing a cost-effective and environmentally sound recycling system. This paper offers an overview of electrical and e-waste recycling, including a description of how it is generated and classified, strategies and technologies for recovering materials, and new scientific developments related to these activities. Finally, the e-waste recycling industry in India is also discussed.

Understanding the origin of the high capacity displayed by Li2MnO3–LiMO2 (M = Ni, Co) composites is essential for improving their cycling and rate capability performances. To address this issue, the Li2Ru1–yMnyO3 series between the iso-structural layered end-members Li2MnO3 and Li2RuO3 was investigated. A complete solid solution was found, with the 0.4 ≤ y ≤ 0.6 members showing sustainable reversible capacities exceeding 220 mAh·g–1 centered around 3.6 V vs Li+/Li. The voltage–composition profiles display a plateau on the first charge as compared to an S-type curve on subsequent discharge which is maintained on the following charges/discharges, with therefore a lowering of the average voltage. We show this profile to evolve upon long cycling due to a structural phase transition as deduced from XRD measurements. Finally we demonstrate, via XPS measurements, the oxidation and reduction of ruthenium (Ru5+/Ru4+) during cycling together with a partial activity of the Mn4+/Mn3+ redox couple. Moreover, we provide direct evidence for the reversibility of the O2– → O– anionic process upon cycling, hence accounting for the high capacity displayed by these materials. This work, by capturing the main redox processes pertaining to these materials, should facilitate their development.

The nature of LDH-based nanostructures and their role in the OER are explored, along with synthetic methods to formulate different structures <italic>via</italic> pioneering modification approaches are discussed for the first time.

Despite the appearance of ever first report on the synthesis of LiNiO2 in 1954, active research to identify and evaluate its suitability as an electrode material in rechargeable lithium batteries started only in late 80’s. Following this, numerous articles discussed the synthesis, electrochemical behavior and the problems associated with the compound. In this connection, the present communication reviews certain important experimental results obtained by different research groups on various aspects of LiNiO2, in order to understand the significance of LiNiO2 as a potential cathode material for rechargeable lithium batteries. Also selected type of methodologies adopted to synthesize the title compound have also been discussed to substantiate the dependence of electrochemical behavior of LiNiO2 on the method of synthesis and reaction conditions. The subject has been discussed at length and may provide useful information on the properties of LiNiO2 and may enable the fabrication of tailor made nickel-based electrode materials for ‘next generation’ lithium or lithium-ion batteries along with the highlights of doped and coated derivatives of LiNiO2.