Search results for "electrolyte"
showing 10 items of 746 documents
Ion-Selective Organic Electrochemical Transistors
2014
Ion-selective organic electrochemical transistors with sensitivity to potassium approaching 50 μA dec(-1) are demonstrated. The remarkable sensitivity arises from the use of high transconductance devices, where the conducting polymer is in direct contact with a reference gel electrolyte and integrated with an ion-selective membrane.
Optimization of anodizing process of tantalum for Ta2O5-based capacitors
2020
Anodic oxides were grown to 50 V on Ta in several organic ions containing anodizing baths. Their properties were compared with anodic Ta oxide film grown to the same formation voltage in 0.1 M NaOH. Anodizing process carried out in sodium citrate led to the growth of the anodic oxide with the best blocking properties whilst, when Ta is anodized in sodium adipate, a significant part of the circulated charge is wasted in side reactions, such as oxygen evolution. Photoelectrochemical measurements showed the presence of optical transitions at energy lower than the band gap for the anodic films grown in citrate and tartrate electrolytes, attributed to localized electronic states located close to…
High-performance of PbO2 nanowire electrodes for lead-acid battery
2014
Abstract PbO2 nanowires were obtained by template electrodeposition in polycarbonate membranes and tested as positive electrode for lead-acid battery. Nanowires were grown on the same material acting as current collector that was electrodeposited too. The nanostructured electrodes were assembled in a zero-gap configuration using commercial negative plate and separator. Cell performance was tested by galvanostatic charge/discharge cycles in a 5 M H2SO4 aqueous electrolyte. PbO2 nanostructured electrodes were able to deliver at 1C rate an almost constant capacity of about 190 mAh g−1 (85% of active material utilization), close to the theoretical value (224 mAh g−1). The nanowire array provide…
Enhancement of pulsed laser removal of metal oxides by electrochemical control
1996
Pulsed laser irradiation of oxidized metallic surfaces in an electrolytic cell under proper voltage conditions is demonstrated to be a promising new approach for effective removal of oxide films. Systematic measurements on simulated corrosion-product films by optical reflectance profile and energy dispersive X-ray spectroscopy are used to study the physical mechanisms of this novel phenomenon, the physical conditions for its observation and its possible generality. It was observed that the utilization of a basic electrolyte solution and the imposition of a certain cathodic potential prior to laser irradiation is an essential requirement for a high removal efficiency. This new technique has …
Electromotive Force Generation with Hydrogen Release by Salt Water Flow under a Transverse Magnetic Field
2011
By considering an electrolyte solution in motion in a duct under a transverse magnetic field, we notice that a so called Faraday voltage arises because of the Lorentz force acting on anions and cations in the fluid. When salt water is considered, hydrogen production takes place at one of the electrodes if an electric current, generated by Faraday voltage, flows in an external circuit. The maximum amount of hydrogen production rate is calculated by basic electrochemical concepts.
Improvement in the performance of low temperature H2-O2 fuel cell with chitosanephosphotungstic acid composite membranes
2016
Abstract Free-standing chitosan/phosphotungstic acid polyelectrolyte membranes, prepared by ionotropic gelation on alumina porous supports, were employed as proton conductor in low temperature H 2 –O 2 fuel cell. A drying step on glass substrate was introduced in the fabrication procedure to reduce shrinkage and consequent corrugation. Membranes were tested with electrodes prepared according to different procedures and with two different Pt loadings, namely 0.5 and 1 mg cm −2 . Both the investigated kinds of electrodes allowed to get very promising power peaks of 550 mW cm −2 in spite of the different Pt content. The polarization curves and the electrochemical impedance spectra suggest that…
Dynamic heterogeneity in polymer electrolytes. Comparison between QENS data and MD simulations
2001
Abstract We have investigated the dynamics of poly(ethylene oxide) (PEO) lithium-based salt electrolytes (PEO–LiBETI) using quasi-elastic neutron scattering (QENS). Measurements were carried out on the spectrometer NEAT (HMI, Berlin) above the melting temperature of PEO ( T m ≈65°C). The experimental data fully support the Molecular Dynamics (MD)-derived model of a heterogeneous dynamics in dilute PEO-salt electrolytes. In agreement with MD simulations carried out on PEO–LiPF 6 , we find evidences for the existence of two dynamic processes: (a) a faster process that is described in terms of the pure PEO dynamics and (b) a second component which we identify with the slower motion of the PEO …
Periodic nanoscale patterning of polyelectrolytes over square centimeter areas using block copolymer templates
2016
© The Royal Society of Chemistry 2016. Nano-patterned materials are beneficial for applications such as solar cells, opto-electronics, and sensing owing to their periodic structure and high interfacial area. Here, we present a non-lithographic approach for assembling polyelectrolytes into periodic nanoscale patterns over cm2-scale areas. Chemically modified block copolymer thin films featuring alternating charged and neutral domains are used as patterned substrates for electrostatic self-assembly. In-depth characterization of the deposition process using spectroscopy and microscopy techniques, including the state-of-the-art scanning transmission X-ray microscopy (STXM), reveals both the sel…
Electrochemical Fabrication and Physicochemical Characterization of Metal/High-k Insulating Oxide/Polymer/Electrolyte Junctions
2014
Photoelectrochemical polymerization of poly(3,4-ethylenedioxythiophene), PEDOT, was successfully realized on anodic film grown to 50 V on magnetron sputtered Ti-6 atom % Si alloys. Scanning electron microscopy allowed us to evidence formation of compact and uniform polymer layers on the oxide surface. Photoelectrochemical and impedance measurements showed that photopolymerization allows one to grow PEDOT in its conducting state, while a strong cathodic polarization is necessary to bring the polymer in its p-type semiconducting state. Information on the optical and electrical properties of metal/oxide/polymer/electrolyte junctions proves that PEDOT has promising performance as an electrolyte…
Creation of Temperature Field in a Finite Cylinder by Alternated Electromagnetic Force
2004
One of the modern areas of applications developed during last years is effective use of electrical energy produced by alternating current in production of heat energy. This process is ecologically clean.The water is weakly electrically conducting medium (electrolyte). Devices based on this principle are developed during last ten years. Compared to classical devices with heating elements, new devices are more compact.