Typical direct borohydride fuel cells (DBFCs) use sodium borohydride (NaBH4) as the fuel and oxygen (O2) as the oxidant. However, for space and underwater applications, where O2 is not available, the gas has been replaced by hydrogen peroxide (H2O2) as a liquid oxidant. Perovskite oxides have been recently proposed as cathodes for H2O2 reduction in DBFCs, overcoming the need for expensive noble-metal electrocatalysts. In this work, perovskite-based discs are sintered in air at temperatures up to 1300 ºC to obtain ceramic samples with fractional density higher that 85 %. Eight different ceramic materials with K2NiO4 structure, namely La2NiO4, La2CuO4, La1.9Pr0.1CuO4, La1.9Sr0.1CuO4, La1.8Ce0.2NiO4, La1.9Pr0.1NiO4, La1.8Pr0.2NiO4 and La1.9Sr0.1NiO4 are tested as electrodes for H2O2 reduction reaction in alkaline media at room temperature. Cyclic voltammetry suggests that La2CuO4 and La1.8Ce0.2NiO4 present significant activity for H2O2 reduction reaction. The activity and stability of these two ceramic materials is further investigated by chronoamperometry and chronopotentiometry.

Borohydride oxidation reaction (BOR) was investigated on different carbon–supported palladium (Pd) electrocatalysts. Namely, Pd nanoparticles were supported on Vulcan XC72, as well onto two biobased carbon materials, MEGSAK and MEVSAK. Electrochemical surface area of three electrocatalysts was determined using cyclic voltammetry. Subsequently, their activity for BOR in alkaline media was studied using linear scan voltammetry with rotating disc electrode. BOR onset potential and number of electrons exchanged were evaluated from the obtained data in order to compare the three electrocatalysts. BOR parameters values were correlated with the electrocatalysts morphology, and the effect of carbon support on their activity for BOR was evaluated.

The importance of oxygen reduction reaction (ORR)in fuel cells and metal/air batteries is well–known. However,designing electrocatalysts with
high performance for ORR remains a challenge.In this work,three novel PdNi
–based composite materials, namely PdNi/(SnO2/KB600), PdNi/(SnO2/KB300) and
PdNi/VulcanXC72 are prepared by standard precipitation method.
The electrochemical activity of each catalyst for the ORR is studied in
alkaline media by voltammetry techniques using rotating disc electrode (RDE).From the RDE data at different rotation speeds and by using Koutecky–
Levich equation, the kinetic parameters of the ORR, such as number of exchanged electrons and kinetic current density,are calculated.
These results show that PdNi–based composite materials possess high electrocatalytic activity for reduction of oxygen in alkaline media.

Sustainability is realized in a place where people live and work and is part of a global framework of sustainability. With the growing challenges faced, the cities are required entrepreneurship and innovation to ensure its own long-term economic, cultural and social progress while reducing the environmental impact. The concept of a circular economy promises a way out. It aims to enable effective flows of materials, energy, labour and information so that natural and social capital can be rebuilt. Finding innovative energy solutions, integrated with transport systems, smart construction and urban planning solutions, waste and water treatment as well as ICT solutions for the urban environment is therefore crucial in the transformation towards a sustainable society.

Typical fuel cells use hydrogen (H2) as the fuel and oxygen (O2) as the oxidant. However, safety issues and the high costs involved in gas storage in pressurised containers are leading many researchers to drive their focus to liquid-feed fuel cells. One option is the direct borohydride fuel cell (DBFC). Basically, the DBFC is an electrochemical device that converts the chemical energy contained in a sodium borohydride (NaBH4) alkaline solution directly into electric energy. While the NaBH4 fuel is oxidised at the anode, oxygen (O2) or hydrogen peroxide (H2O2) oxidants are reduced at the cathode. The use of liquid reactants makes the DBFC a promising solution for space, underwater, and specific terrestrial applications where O2 is not available. Most of the current research on the DBFC is focused on the development of inexpensive electrocatalysts that are able to efficiently catalyse the fuel cell reactions.
Like having flashbacks from the past, herein we briefly review the main studies that we have carried out in the last 10 years in the development of electrocatalytic materials for application in DBFCs, both for NaBH4 oxidation and for O2/H2O2 reduction. The advantages of high energy density and room temperature operation suggest future use of the DBFC for portable applications.

Design of an innovative utilization technology for cellulose - a promising, environmental-friendly and renewable resource for the production of valuable chemicals and raw materials for industry - offers a new platform in our efforts towards sustainable society. In recent years, a new reaction pathway from cellulose was found and the key parameters of the process were investigated. The process involves electro-oxidation of cellulose mediated by an Au electro-catalyst in alkaline media that converts water insoluble cellulose into water soluble functional materials. In the reaction, adsorption of OH anions onto the electrode surface plays an important role for the electrochemical functionalization of cellulose molecule. Considering the mechanism of the reaction, it is expected that additional new functional materials can be obtained from cellulose by applying special solvents having OH anions that are designed for the electro-oxidation of cellulose. In this work, we synthesized and designed special solvent systems based on ionic liquids - one of the most powerful solvent systems for cellulose dissolution - in order to construct an innovative reaction platform for the design of the series of functional materials and valuable chemicals from cellulose.
The electrochemical reactivity of cellulose in the tailor-made IL systems was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) under N2 atmosphere. The reaction products were characterized by (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). For the first time, it was discovered that the cellulose can be oxidized directly at an Au electrode surface in an IL system. Thus, this opens a new research topic as well as a promising technology to produce different types of functional materials and chemicals for industry.

Electrochemical technologies can be used for the treatment of domestic wastewaters, by eliminating their organic pollutants. They have advantages over conventional methods, such as environmental compatibility, versatility, energy efficiency, safety and cost. The organic compounds degradation process is based on the production of OH radicals, formed during water electrolysis, which will oxidize the organic molecules producing CO2. At the same time, hydrogen (H2) can be produced through reduction of the water in the effluent, which can be later used in a fuel cell. The present study seeks to find effective electrocatalysts to produce H2 by electrolysis, using a domestic wastewater as a hydrogen source, with or without the addition of electrolytes. Cyclic voltammetry (CV) is performed using several different cathode materials, namely platinum (Pt) and platinum-rare earth (Pt-RE) binary alloys, and nickel (Ni) and Ni-RE alloys, with the REs being cerium (Ce), samarium (Sm), dysprosium (Dy), and holmium (Ho). CV measurements are conducted at different temperatures, ranging between 25 and 85 ºC. KOH was selected for electrolyte, as the extra hydroxide can be used to degrade the organic matter. The data obtained for the hydrogen evolution reaction (HER) at the different electrode materials is compared. It is noticeable that the effluent containing the KOH additive leads to significantly better performances.

LiNi0.5Mn1.5O4 is a promising cathode for lithium batteries owing to its high operation voltage, however its application is restricted by poor high rate performances. Doping and carbon coating are effective methods to enhance the electrochemical performances. Ru and Co doping have been carried out to improve the conductivities, and enhanced high rate performances have been achieved. High temperature carbon coating on LiNi0.5Mn1.5O4 has been investigated. Scanning/transmission electron microscope (S/TEM)observation shows clear coating layer on the particle's surface; Energy Dispersive X-Ray Spectroscopy (EDX), Raman spectra and Brunauer-Emmett-Teller (BET) tests indicate the amorphous carbon coating layer could be obtained at 800 A°C without using reducing gas or introducing additional low temperature treatments, and the coating layer can significantly increases the BET surface area. The high temperature carbon coating process puts significant influence on the crystal structure in terms of degree of cation ordering and Mn3+ concentration, and eventually the high rate performances.

Direct alcohol fuel cells (DAFCs) are promising devices to power portable applications, and ethanol is considered one of the most interesting fuels in this field. In this work, platinum-rare earth (Pt-RE) binary alloys (with RE = Ce, Sm, Dy, Ho) with at least 50 at.% RE, were produced and studied for ethanol oxidation in alkaline medium. Their electrocatalytic performance is evaluated using cyclic voltammetry, with several ethanol concentrations [0.2 - 0.8 M], in the temperature range 25 - 45 ºC. Kinetic parameters such as number of exchanged electrons, transfer coefficients and reaction order are determined. Pt-RE electrodes showed higher current densities for ethanol oxidation reaction than Pt electrode.

NASA has teamed with the DOE to develop Fission Surface Power technology to support flight power systems for lunar outposts and later missions to Mars. The Fission Surface Power System recommended as the initial baseline design includes a liquid metal primary coolant system that transfers heat to two intermediate liquid metal heat transfer loops. Each intermediate loop transfers heat to two Stirling engines. Both the primary and intermediate loops will use sodium-potassium (NaK) as the liquid metal coolant, and the primary loop will operate at temperatures exceeding 600A°C. The alloy selected for the heat exchangers and piping is AISI Type 316L stainless steel. The interaction between the high-temperature coolant and the stainless steel welds remains an uncertainty for the projected eight year life of the system, and the goal of this research is to select an optimum weld configuration for the heat exchanger tube to sheet welds.
Gas tungsten arc and electron beam weld specimens in several candidate configurations have been made for testing. Liquid metal transfer, especially nickel leaching, is a concern in a high-temperature liquid metal loop. A compact natural circulation loop has been designed to operate at 600A°C with a complement of 64 weld specimens positioned in a furnace. The loop is contained in an argon glove box so that the NaK can be handled safely, especially in the case of leakage, which has been experienced during operation. NaK flow velocity has been measured by pulse heating a spot in the loop and measuring the temperature rise along the loop, and was determined to be 0.2-0.4 cm/s. Specimens will not be discharged prior to six months exposure with subsequent discharges at one and two years. It is anticipated to extrapolate behavior to the goal of eight years operation by specimen mass gain and microscopy analysis.
Key Words
Welding, space reactor, stainless steel, NaK

There has been an explosive growth of research dedicated to new electrochemical energy storage devices in the last decades. Among these devices, redox supercapacitors (SCs) have emerged as very attractive solutions for several applications. These devices are pin pointed as strategic materials in the European Roadmaps for materials enabling low carbon technologies. It is therefore not surprising that although supercapacitors have already encountered their place in the energy storage global market, research efforts continue in order to develop electrode materials that can further enhance SCs energy density, while maintaining a high power density.
In this context, SCs electrode materials have been produced by different methods. Electrodeposition has stood out in comparison with many other synthesis routes due to important features such as cost-effectiveness, high quality deposits, production at room temperature (no need of high vacuum), scale-up ability, and easy operating conditions.
In this work, we have designed nanostructured porous single and mixed transition metal oxides/hydroxide electrodes, and its composites with carbon nanofoams, for developing high energy density charge storage electrodes for SCs. The electrodes were fabricated by a one-step process, consisting on the electrodeposition of transition metal oxides on stainless steels or on carbon nanofoams.
Electrodeposition of manganese, nickel and cobalt oxides/hydroxides was performed from the corresponding salt electrolytes at constant or under pulsed potential.
The morphology, chemical composition and phase composition of the electrodeposited electrodes were studied by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Raman spectroscopy.
The electrochemical performance of the electrodes was studied by cyclic voltammetry and chronopotentiometry (charge-discharge cycles) and the specific capacitance of the material was calculated from the experimental data. The variation of capacitance was related to the substrate material and morphology of the electrodeposited oxides and hydroxides.
The results demonstrate that the morphology and composition of the metallic transition oxides/hydroxides electrodes and its composites can be tailored by changing the electrodeposition parameters. The results also evidence that it is possible to fabricate charge storage electrodes, displaying specific capacitances 2-4 times above those of the conventional carbon-based double layer capacitors.
The composites obtained with carbon nanofoams reveal an increased working potential window, in aqueous electrolytes, up to 2.1 V, thus resulting in electrodes that can be assembled in devices that display enhanced energy density.
In conclusion, electrodeposition allows fabricating a new class of advanced electrodes for redox supercapacitors, based on 3D architectures of transition metal oxides/hydroxides and its composites with carbon nanofoams, capable of attaining energy density values much above commercial carbon-based solutions.
Keywords: charge storage, supercapacitors, transition metals, carbon nanofoams.

Black liquor is a pulp mill effluent from wood cooking and has a solid content of 15-18% (weak black liquor), which is mostly lignin, an organic compound that finds wide applications in the market. Black liquor is currently used for steam generation purposes, by burning it, which is not an efficient process due to the undifferentiated combustion of the liquor, losing most of the lignin potential. Considering the world’s energy picture, it is essential to develop sustainable energy generation alternatives, including through waste recovery. Having this in mind, the current work focuses on the electrolysis of black liquor for energy recovery. The process has several economic and environmental advantages, as it simultaneously generates a clean fuel (hydrogen) and a precipitated material with economic value (lignin). The generated hydrogen can be fed to a fuel cell that partially powers the electrolysis plant, thereby decreasing the electricity costs. Herein, platinum (Pt) and nickel (Ni) bulk electrodes are tested for black liquor electrolysis. Cyclic voltammetry, chronoamperometry, and chronopotentiometry are used to study the lignin anodic oxidation at the Pt and Ni electrodes. Kinetic and diffusional parameters are calculated (e.g., charge transfer and diffusion coefficients, number of exchanged electrons). The hydrogen evolution reaction in the black liquor is also evaluated at room temperature. Finally, a small-scale laboratory black liquor electrolyzer using Ni plates, both for anode and for cathode, is assembled and its operation parameters are evaluated.

China needs to develop nuclear energy much more actively from the point of supporting economic sustainable increase and environmental protection. Significant efforts have been made on the research of some key component applied materials and the manufacturing technology of the Pressurized Water Reactors (PWRs) in the recent decade in China. Alloy 690 is a nickel based corrosion resistant material and has been extensively applied as the steam generator (SG) tubing in the PWRs. In order to prolong the SG service life to more than 60 years, this tubing material's basic characters and manufacturing foundation need to be clarified and established step by step. The fundamental research of the minor and trace elements effects on microstructure, property and the development of manufacturing homogenized industrial scale Alloy 690 are reviewed in this paper.
From the study of the Alloy 690 isothermal solidification behavior, sulfur (S) was found to lower the solidus temperature significantly. This element largely enriched in final solidified residual liquids and significantly induced main elements' micro-segregation. Accompanied by the co-segregation of Cr and Ti, chromium sulfides or titanium sulfides were formed, which was proved to be rather detrimental to alloy hot ductility. Its content, therefore, needs to be controlled as low as possible in industrial production. Nitrogen (N) has a diplex function. It refines the grain size and increases alloy strength without decreasing ductility, but more TiN particles will be precipitated when more N is added to this alloy, so N content should be controlled within a reasonable range. A high purity industrial scale alloy melting process has been successfully developed by taking vacuum induction melting (VIM) and electro-slag re-melting (ESR) double routes.
In order to fully understand the ESR ingot's crystal structure and the structure evolution after hot forging, an ESR ingot with 510mm diameter has been dissected both from transverse and longitudinal directions. It could be found that at three typical re-melting stages, the ingot possesses different crystal macro-structures. Further micro-structure analysis shows nitrides solidified in the inter-dendrite, carbides only precipitated at the grain boundary. The structure evolution has been carefully studied using the samples taken from different sections of the dissected ESR ingot and hot-forged at different temperatures. There were some kinds of fine-grain bands structure which was observed in the hot forged parts, and the fine grain boundaries were beset by some of chromium-carbide. Such fine-grain bands would be inherited to the hot extruding or cold rolling tubes if they could not be eliminated after hot forging of the big ESR ingot. By optimizing the ingot hot deforming process, the forging billets of 210 diameters with more stable and uniformed structure were obtained.

Nano zero-valent iron (nZVI) is widely used to remediate groundwater and wastewater from heavy metals and stable organic pollutants (Permeable Reactive Barriers). This is caused by the fact that Fe0 reduces several halogenous hydrocarbons, chlorine-containing pesticides, organic dyes, nitrozo compounds, explosives and others. The restoring ability is used for reduction of CrO4-2, Cr2O7-2, ClO4-, NO3- ions and elimination of Hg+2, Ni+2,Cd+2, Pb+2 as well as of a number of radionuclides from water. nZVIs had found wide application in the USA but in Europe this method appeared later. The cost of these methods for remediation of water depends on many factors (type of pollution, cost of reagents, the purpose and degree of remediation, remediation methods and other). That is why revealing of new reductants and methods for reduction of Fe+2 and Fe+3 up to Fe0 is an actual problem. The objective of the present research is impregnation of nZVL in bioorganic materials and obtaining of hybrid organic-inorganic reactive barriers.
In this paper, we present preliminary results on the development of methods for impregnating of the nZVI in biopolymers. On the basis of these materials, it is possible to obtain cheap biosorbents with versatile properties able to simultaneously remove the heavy metals (including radio nuclides) and stable organic pollutants. Biopolymers contain many complex-forming functional groups, including hydroxyl, carboxyl, carbonyl, ether and other groups. These groups have the ability to stabilize the nanosize particles and prevent formation of large-size particles. Biosorbents have a high sorption capacity towards ions of heavy metals, which are higher than a similar capacity of inorganic sorbents. The matrix (biomaterial) plays a role of a sorbent of heavy metals and on the other hand the particles of impregnated iron are reactive barriers for toxic metal ions and stable organic pollutants. A method for activation of biomaterials (wood processing wastes, sawdust, shavings, chips, cereal crop residues) has been developed, which includes their hydrothermal treatment at 2000C at a pressure of 2,0-2,5 MPa(for 1 h) and then rapid reduction of pressure that leads to decomposition of the wood structure and increase of the surface. Immobilization of nZVI in biopolymers and in wood of some plants has been carried out by chemical method (by sodium borohydride) and by plant extracts. It was determined that the wood of some local plants is a reduction agent for iron compounds. The possibility of obtaining nZVI in wood present in its reducing agents gives us hope that it is possible to create a new type complex biosorbent by methods of "green chemistry" that excludes stages extraction of reductants from biomaterials. It is determined that with similar methods, it is possible to impregnate (apply) nZVI in porous inorganic compounds.
Microstructure of sorbents has been studied by optical and electronic scanning microscopes (NIKON ECLIPSE LV 150, NMM-800TRF, NANOLAB-7). Sorbents have been analyzed by XRD method on the diffractometer DRON-3M (Cu-KI±, Ni filter, 2O/min).

Monocrystalline Si-Ge alloys are characterized by the improved electrophysical characteristics, radiation resistance and fracture strength. These circumstances stipulate high perspectives for their photovoltaic and optoelectronic applications. An investigation of structural-sensitive mechanical properties of monocrystalline Si-Ge substrates with various Ge concentration is important for the solution of deliberate control of their structural and physical characteristics.
The present work deals with the investigation of internal friction and shear modulus temperature spectra and microhardness of non-doped monocrystalline Si1-xGex(x<0,02) substrates. Samples surfaces with (111) crystallographic orientation have been prepared by standard mechanical and chemical polishing methods. Decrease of activation energy of relaxation processes and nonmonotonic changes of shear modulus have been revealed in 0,5-5,0Hz oscillation frequency and 20-750 C temperature ranges. Investigation of microhardness and elastic modulus by Vickers indentation method were performed on Shimadzu device. It is shown that with increasing concentration of germanium microhardness the elasticity modulus decreases. Observed changes are discussed from the point of view of interaction of various dislocations with point defects and their complexes in a real structure of Si-Ge substrates.

The Wind power available on the Earth atmosphere is much larger than the current world power consumption. Its potential on land and near shore is believed to exceed 72 TW. This is equivalent to 54 millions of tons of oil per year, or over five times the total combined world power from all sources. In addition, wind power is clean and renewable without any form of emissions or residues and it does not involve the depletion of any form of fuel. The growth in new capacity has exceeded 30 percent over the last five years and is expected to continue and/or exceed this trend for many years to come. This means that the wind power industry is currently experiencing a very rapid development stage but is far from reaching its mature stage. Currently, it faces many important challenges and opportunities but its potential is extraordinary. The environmental impacts are very few but not in depth such as noise and potential disturbance in landscape, fauna and flora. Advances in power grid characteristics and recharging technology are expected to be considerable enablers. This paper discusses typical challenges and opportunities in mechanical and materials design and manufacture with particular focus on the potential of nano-composites and hybrid materials for application in new environments and geographic locations both land-based and offshore.

TiO2 (anatase) and TiO2(B)(monoclinic polymorph of TiO2) are attractive candidates for anodes in rechargeable Li-ion batteries, due to their cycling stability, reasonable capacity and operating potential. Li insertion into TiO2 polymorphs proceeds as a diffusion controlled process, where the peak current scales with square root of the scan rate. Excess Li can be accommodated either at the interfaces of the nanometer-sized particles or at the open channels in the structure of particular polymorphs by a pseudocapacitive faradaic process, which is not controlled by diffusion. In this case, currents in the peaks of cyclic voltammograms of Li scale with the first power of scan rate.
Li-insertion electrochemistry of TiO2(B) is basically different from that of anatase. Accommodation of Li in the TiO2(B) lattice manifests itself by two pairs of peaks in cyclic voltammogram with formal potentials of ca. 1.5 and 1.6 V. Zukalova et al found that Li-insertion into TiO2(B) is characterized by unusually large faradaic pseudocapacitance. This peculiar effect was ascribed to Li+ accommodation in open channels of TiO2(B) structure allowing fast Li-transport in TiO2(B) lattice along the b-axis (perpendicular to (010) face). Deeper insight into differences between charging mechanisms of TiO2(B) and anatase during Li+ insertion provides analysis of cyclic voltammograms of Li insertion. The ratio of capacitive contributions to overall charge of Li-storage was found to be over 30% higher in TiO2(B) compared to that in anatase nanocrystals. The predominant pseudocapacitive process in TiO2(B) was related to accommodation of Li inside the TiO2(B) open channels in monoclinic lattice.
This work was supported by the Grant Agency of the Czech Republic (contracts No. 13-07724S and 15-06511S).

As typical electrochemical energy storage devices, supercapacitors and lithium ion batteries have potential applications in a wide range of fields such as microelectronic devices, portable electronics, and large-scale electric vehicles, etc. Electrode materials are one of the key aspects determining the performance of these two devices (Jiang et al., 2012). In this talk, I will mainly discuss the electrochemical energy storage application of one kind of emerging electrode architecture, that is, metal oxide-based nanostructure arrays grown directly on current collector substrates (Jiang et al., 2011). The direct growth of nanostructures on current collector represents a popular way to fabricate thin-film electrodes, which not only ensures good charge transport, but also provides sufficient structural interspaces for buffering volume expansion of the electrode materials. When combined with using flexible current collector, such thin-film electrode also has greater durability to shape deformation, giving better mechanical flexibility. By pairing appropriate electrode materials, ordered core-shell and hierarchical hybrid nanostructures can be rationally designed, which leads to synergistic improvement in terms of electrical/ionic conductivity, electrochemical stability and structural integration (Liu et al., 2011). Hybrid electrode materials with high capacitance/capacity, long cycle life and exceptional rate capability can thus be obtained; the related performance enhancement mechanism will also be discussed in detail. In the end, I will further show that these binder-free nanoarray electrodes have enabled high-performance thin-film/flexible energy storage devices (Zhou et al., 2013).
References
Jiang J, Li YY, Liu JP, 2012. Recent Advances in Metal Oxide-based Electrode Architecture Design for Electrochemical Energy Storage. Advanced Materials 24: 5166-5180.
Jiang J, Liu JP, 2011. Building One-Dimensional Oxide Nanostructure Arrays on Conductive Metal Substrates for Lithium-Ion Battery Anodes. Nanoscale 3: 45-58.
Liu JP, Jiang J, Cheng CW, 2011. Co3O4 Nanowire@MnO2 Ultrathin Nanosheet Core/Shell Arrays: A New Class of High-Performance Pseudocapacitive Materials. Advanced Materials 23: 2076-2081.
Zhou C, Zhang YW, Li YY, Liu JP, 2013. Construction of High-Capacitance 3D CoO@Polypyrrole Nanowire Array Electrode for Aqueous Asymmetric Supercapacitor. Nano Letters 13:2078-2085.

Rechargeable batteries are receiving particular attention in diverse areas of portable electronic devices, electric vehicles (EV) and other energy storage systems. We previously reported the proof-of-principle of a new concept of rechargeable batteries based on chloride shuttle, i.e., chloride ion batteries. The concept has the advantage of a broad variety of potential electrochemical couples with high theoretical energy density up to values of 2500 Wh/L, which is close to the theoretical energy density of the Li/S battery. Moreover, chloride ion batteries can be built from abundant material resources and have environmentally friendly features. These attributes could make the chloride ion battery a potential alternative in the field of rechargeable batteries.
A key challenge is to suppress the dissolution of cathode materials mainly composed of transition metal chlorides, which are Lewis acid and can react with a Lewis base containing chloride ion in the electrolyte, resulting in the formation of soluble complex ions. One approach is to use metal oxychlorides as cathode materials. For the FeOCl cathode (FeOCl/Li), a discharge capacity of 158 mAh g-1 was measured in the first cycle and a stable discharge capacity of 60 mAh g-1 in after 30 cycles. These results suggest that metal oxychlorides are promising cathode materials for chloride ion batteries.
A key advantage of chloride ion batteries is the use of abundant materials such as Mg, La, Ca and Na as anode materials. We found that Mg is promising as anode material based on our new results. For instance, the BiOCl cathode (BiOCl/Mg) showed a discharge capacity of 70 mAh g-1, i.e., 68% of theoretical capacity at the second cycle. The electrochemical performance of metal oxychloride/Mg systems was investigated including single electron or multi-electron cathode. Moreover, a new approach was tested using multi-electron vanadium oxychloride cathode and Mg/MgCl2 composite anode.

The clay used in this study was from Algeria. The mineralogical and physico-chemical properties of clays have been determined. Chemical, X- ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscopy (TEM) analysis of the clays reveal that the main mineral present are Montmorillonite, Smectite, Kaolinite, Calcite and Quartz. X-Ray Diffraction clearly shows that the d-spacing of clay increased from 12.93 Å to 16.50 Å, which could be attributed to the activated clay. Quartz (reflection at 2Ɵ = 35.97°) and calcite (reflection at 2Ɵ = 35.97°) are the major impurities. Activation decreased the iron, calcium and magnesium content and increased the silica and alumina content. Montmorillonite is the major clay mineral. IR techniques have been used to identify natural and activated clay minerals. The region above 3000 cm−1 wavenumber contains information about the silanols and the characteristic vibration peaks of montmorillonite are identified at 3625 cm−1 (O–H stretching). The high intensity of the peak appearing at 1039 cm-1 is an indication of the large amount of this mineral in the sample. In continuation of previous works carried out in this field, in the present work, a more efficient method for modification of Clay was studied.

Sustainable and renewable energy sources, such as hydropower, solar energy, and wind power, in conjunction with flexible energy storage systems, such as rechargeable batteries and supercapacitors, are one of the key solutions to release the heavy burden on the current energy infrastructure and the environment. Recently, supercapacitors have emerged as a new class of promising energy storage devices because of their higher power density, faster charge-discharge rate, and longer cycle lifetime than those of rechargeable batteries. Supercapacitors can also store more energy than conventional dielectric capacitors. The central issues in the development of practical supercapacitors are the selection and fabrication of high-performance electrode materials. Among the emerging electrode materials for supercapacitors, redox-active transition-metal oxides such as RuO2, NiO, Fe2O3, SnO2 and MnO2, are the most attractive materials due to their high specific capacitances from the fast and reversible redox reactions on the electrode surface.
In particular, MnO2 has drawn recent interest as a potential electrode material for supercapacitors because of its high specific capacitance (theoretical value of ~1370 F/g), low cost, natural abundance, and environmental benignity. However, the practical use of MnO2 as electrode materials is largely weight-down due to its poor electrical conductivity (10-5 - 10-6 S/cm), which limits the charge-discharge rate of the supercapacitors; as well as a relatively small surface area of bulk MnO2, which constraints the energy that can be stored in a particular electrode. An effective way to improve the utilization of MnO2 (thus increasing the energy density) is to reduce the MnO2 particles to the nanometer range, in which small particles have a characteristic high surface to volume ratio. The major strategy to improve the electrical conductivity of the MnO2 electrodes is to combine conductive materials (e.g., carbon-based materials, metals, and oxides) to MnO2, forming MnO2 composite electrodes with improved conductivities.
In our recent works, various MnO2 nanosturctures, including nanowires, nanoflakes, nanotubes and nanoporous structure, have been prepared by facile methods, such as electrodeposition and hydrothermal synthesis, and their supercapacitive properties have been systemically investigated. In order to overcome the poor electrical conductivity of MnO2, a core-shell hierarchy architectured MnO2/CNT nanocomposite was designed and fabricated. The MnO2/CNT nanocomposite electrode exhibits much higher specific capacitance compared to those of the CNT and the pure MnO2 electrodes and significantly improved rate capability compared to that of the pure MnO2 electrode. To provide a three-dimensional conductive scaffold that can maximize the loading of nano MnO2 and increase the area-normalized capacitance, we proposed a novel architectural design of a ternary MnO2-based electrode - a hierarchical Co3O4@Pt@MnO2 core-shell-shell structure, where the complemental features of the three key components (a well-defined Co3O4 nanowire array on the conductive Ti substrate, an ultrathin layer of small Pt nanoparticles, and a thin layer of MnO2 nanoflakes) are strategically combined into a single entity to synergize and construct a high-performance electrode for supercapacitors. More discussions will be given in the conference.

R&D activity performed during the last three decades has identified four plausible, long-term markets and energy solutions that fuel cell systems may offer: lowest cost energy to end users; solutions for combined heat and power or high-value premium power; peak-shaving solutions; and load-management and grid-power support for unreliable or inconsistent supply. Accordingly, towards rapid commercialisation of fuel cell products in the coming years, the fuel cell system is being redefined by means of a strong concentration on lowering costs of basic elements, electrolytes and membranes, electrode and catalyst materials, and increasing power density and long-term stability. Among different kinds of fuel cells, low-temperature polymer electrolyte membrane fuel cells (PEMFCs) are of major importance, but their problems related to hydrogen storage and distribution are forcing the development of liquid fuels such as methanol, ethanol, sodium borohydride and ammonia. In respect to hydrogen, methanol is cheaper, easier to handle, transport and store, and has a high theoretical energy density. The second most studied liquid fuel is ethanol, but it is necessary to note that the highest theoretically energy conversion efficiency should be reached in a cell operating on sodium borohydride alkaline solution. Independently of these fuel cell types, it is clear that proper solutions need to be developed, by using novel catalysts, namely nanostructured single phase and composite materials, oxidant enrichment technologies and catalytic activity increasing. In this lecture, these main directions will be considered.

Nanostructured lead oxides containing carbon were prepared in order to fabricate a lead acid battery from decomposition of lead citrate precursor (Pb3(C6H5O7)2iƒ—3H2O) which was synthesized firstly by leaching spent lead acid battery paste in aqueous citrate salt system. The effects of different parameters on particle size and morphology of the final lead oxide products were optimized. The products were characterized by scanning electron microscopy, X-ray diffraction, surface area and pore size analysis and electrochemical test. The results show that the morphology of obtained carbon materials vary with the decomposition temperature. The combined lead oxide with carbon, when applied as a cathode in a lead-acid battery, is shown to be capable of conveying 30% higher energy-density and better performance during high-rate partial-state-of-charge (HRPSoC) operations compared with the traditional leady oxide made by ball-milled process. The new method has the potential for providing a possibility of manufacturing high-performance lead acid battery used for hybrid electric vehicles (HEVs).
Keywords: Lead oxide; Carbon; Nanostructure; Lead acid battery; Energy-density; electrochemical test

Fuel cells are electrochemical devices that transform directly the chemical energy of a fuel into electricity. Thereafter, significant attention of the research community is devoted to the development of different types of fuel cells for a wide range of applications, from space programs to portable electronic devices, depending on their nominal power. Though hydrogen is the most suitable fuel for various applications, it does not exists in nature as such and its clean, large-scale production, storage and distribution are severe drawbacks for the development of hydrogen-fed fuel cells. In this context, liquids fuels like alcohols are more suitable as their storage, handling, and distribution are significantly simpler. Consequently, alcohols are seen as possible alternative fuels, having additional advantages of high energy density and possibility of being produced from renewable sources. Direct methanol fuel cells and direct ethanol fuel cells represent proton exchange membrane fuel cells operating with methanol and ethanol as fuel, respectively. Herein, working thermodynamic and kinetic principles of a fuel cell, as well as the electrocatalysis and the rate of fuel cell oxidation and reduction reactions, will be discussed. Furthermore, the main characteristics of methanol and ethanol fuel cells will be presented. In particular, some of the most important issues that hinder the development of commercial direct alcohol fuel cells are described along with the effect of various parameters on the cells performance. Clearly, the most complex challenge for cell operations is the slow oxidation and reduction kinetics, requiring development of highly electrocatalytically active electrode materials. This question is also addressed, but a more detailed discussion is provided in another symposium’s lecture on materials for fuel cells.

The world's economy, just like our own way of life, is completely dependent on the access to energy. With the health problems arising from the pollution resulting from the consumption of fossil fuels and the unavoidable issue of the depletion of the non-renewable resources needed for their production, finding new, clean, and efficient fuels is a priority. Hydrogen is a promising alternative to be used as an energy carrier as it is the lightest and most abundant element in the Universe. Moreover, hydrogen is an extremely clean fuel as the only waste produced from its consumption is water. One way to produce hydrogen is via water electrolysis, by splitting the water molecule into oxygen and hydrogen when applying a potential difference between two electrodes immersed in an aqueous electrolyte. The main drawback of this process is its capital and operation costs, since a high overpotential is necessary for the hydrogen evolution reaction (HER) to take place. In order to overcome this issue novel efficient electrocatalysts are required to improve the electrolysis performance. This work intends to study Pd alloys as cathode electrocatalysts, namely PdAu, PdFe and PdFeAg alloys supported on reduced graphene oxide (rGO). The prepared electrodes are submitted to linear scan voltammetry, chronoamperometry and chronopotentiometry studies to characterise their activity for HER in alkaline media. The activity of the tested electrodes towards water electrolysis was established based on the obtained data.

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