Search results for "Cathode"
showing 10 items of 296 documents
On the Effect of Surface Treatment to Improve Oxidation Resistance and Conductivity of Metallic Interconnects for SOFC in Operating Conditions
2008
International audience; Due to the reduction of operating temperature from 1000°C to 800°C, chromia forming alloys are the best candidates for interconnects in Solid Oxide Fuel Cells (SOFCs). These interconnects have to be operational in service conditions, at 800°C in air (cathode side) and in humidified hydrogen (anode side). The performance of the interconnect stainless steels is limited by the oxide scale formation (chromia), the low electronic conductivity of this scale and the possible volatility of chromium oxides. In the field of high temperature oxidation of metals, it is well known that the addition of a nanometric layer made of reactive element oxide such as, La2O3, Nd2O3 and Y2O…
Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL
2011
International audience; As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to postacceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R&D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the gui…
Energy conversion efficiency in betavoltaic cells based on the diamond Schottky diode with a thin drift layer
2020
The HPHT diamond Schottky diode was assembled as a Metal/Intrinsic/p-doped structure betavoltaic cell (BC) with a very thin (1 μm) drift layer and tested under 5–30 keV electron beam irradiation using a scanning electron microscope (SEM). The effect of the β-radiation energy and the backscattering of electrons on the energy conversion was studied. From the results obtained, it is shown that, the efficiency of the investigated BC increases from 1.01 to 3.75% with the decrease of β-particle energy from 30 to 5 keV due to an increase of the electron beam absorption in a thin drift layer. Maximum efficiency is achieved when the electron beam energy is close to the average β-decay energy of 3H. …
Effect of pressure on the electrochemical generation of hydrogen peroxide in undivided cells on carbon felt electrodes
2017
The electrochemical generation of H2O2can be performed in aqueous solutions by cathodic reduction at carbonaceous cathodes of oxygen coming from air. The performances of the process in terms of concentration of H2O2and current efficiency (CE) are limited by the low solubility of oxygen in water at atmospheric pressure. However, the solubility of oxygen can be increased upon enhancing the air pressure. The effect of pressure on the electrochemical generation of hydrogen peroxide was studied in undivided cells changing the pressure from 0 to 30 relative bar and the current density from 1 to 100Â mAÂ cmâ2. Simple carbon felt and compact graphite cathodes were first used. A dramatic effect of…
Optimized morphology and tuning the Mn3+ content of LiNi0.5Mn1.5O4 cathode material for li-ion batteries
2023
The advantages of cobalt-free, high specific capacity, high operating voltage, low cost, and environmental friendliness of spinel LiNi0.5Mn1.5O4 (LNMO) material make it one of the most promising cathode materials for next-generation lithium-ion batteries. The disproportionation reaction of Mn3+ leads to Jahn–Teller distortion, which is the key issue in reducing the crystal structure stability and limiting the electrochemical stability of the material. In this work, single-crystal LNMO was synthesized successfully by the sol-gel method. The morphology and the Mn3+ content of the as-prepared LNMO were tuned by altering the synthesis temperature. The results demonstrated that the LNMO_11…
DC01 steel corrosion resistance in cathodic polarization
2016
Celem prowadzonych badań było okreœlenie odporności korozyjnej stali DC01 poddanej katodowej polaryzacji w zmiennych warunkach. Elektrochemiczne pomiary służące do oceny odpornoœci korozyjnej stali nienawodorowanej poddanej katodowej polaryzacji przeprowadzono metodami obejmującymi pomiar potencjału obwodu otwartego i zarejestrowania zależności i=f(E) podczas badań polaryzacyjnych w trójelektrodowym układzie pomiarowym. Do pomiarów wykorzystano układ składający się z naczynka pomiarowego, potencjostatu AMEL PSW01 System 5000 oraz komputera z oprogramowaniem „CorrWare”. Wodorowanie stali zrealizowano w wodnym roztworze 0,1 N kwasu siarkowego(VI) z dodatkiem 2 mg/dm3 tlenku arsenu(III) jako p…
Microbial Fuel Cell with Ni–Co Cathode Powered with Yeast Wastewater
2018
Wastewater originating from the yeast industry is characterized by high concentration of pollutants that need to be reduced before the sludge can be applied, for instance, for fertilization of croplands. As a result of the special requirements associated with the characteristics of this production, huge amounts of wastewater are generated. A microbial fuel cell (MFC) forms a device that can apply wastewater as a fuel. MFC is capable of performing two functions at the same time: wastewater treatment and electricity production. The function of MFC is the production of electricity during bacterial digestion (wastewater treatment). This paper analyzes the possibility of applying yeast wastewate…
Solid-state compatibility of Ca:LaNbO4 with perovskite cathodes: Evidences from X-ray microspectroscopy
2022
The solid-state compatibility between calcium-doped lanthanum niobate and three perovskite cathode materials was investigated using two X-ray microbeam techniques, micro X-ray fluorescence and micro X-ray absorption spectroscopy. The cathode powders (lanthanum strontium ferrite, either cobalt or copper-doped, and lanthanum strontium cobaltite) in contact with the dense electrolyte pellet were annealed at 1150 degrees C for 12-144 h to simulate the effect of thermal stresses due to fabrication and long-term operation. As a result, several interdiffusion phenomena were then observed on the bilayer cross-sections: in particular, the chemical state and coordination environment of calcium, iron,…
Cation Diffusion and Segregation at the Interface between Samarium-Doped Ceria and LSCF or LSFCu Cathodes Investigated with X-ray Microspectroscopy
2017
The chemical compatibility between electrolytes and electrodes is an extremely important aspect governing the overall impedance of solid-oxide cells. Because these devices work at elevated temperatures, they are especially prone to cation interdiffusion between the cell components, possibly resulting in secondary insulating phases. In this work, we applied X-ray microspectroscopy to study the interface between a samarium-doped ceria (SDC) electrolyte and lanthanum ferrite cathodes (La0.4Sr0.6Fe0.8Cu0.2O3(LSFCu); La0.9Sr0.1Fe0.85Co0.15O3(LSCF)), at a submicrometric level. This technique allows to combine the information about the diffusion profiles of cations on the scale of several micromet…
Cu-B alloy - analysis of use possibility as fuel cell cathode catalyst
2016
In recent years there has been a development of non-conventional and renewable sources of energy. One such sources of energy are fuel cells. Fuel cells are ecological and high efficiency sources of electric energy. However, the use of fuel cells on a large scale is limited, mainly by the high cost of catalysts. Platinum is most commonly used as the catalyst. But due to the high price of platinum there’s a need for finding other catalysts. Replacement of platinum will contribute to the fast development of green energy sources. This paper presents a study of possibility of using Cu-B alloy as catalyst for oxygen electrode in fuel cells. Researches were done in glass vessel, on a copper electr…