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[en] A re-usable in-situ-SQUID electrochemical cell for magnetisation studies during electrochemical cycling is presented. The proof of function is demonstrated by recording reversible magnetisation changes in LiFeO nanoparticles upon electrochemical cycling. The data imply the transition from inverse spinel structure (x=0) to a rocksalt phase (x=2). In addition, the setup is utilised to study the effect of lithiation on the Mott-Hubbard transition in VO.
[en] Highlights: • Comprehensive description of an experimental apparatus for coulometric titrations. • In-detail discussion of difficulties and challenges. • Validation of the system by measurements conducted in the Li-Sn system. - Abstract: The thermodynamic description of Li containing systems is readily accessible by coulometric titrations in combination with EMF measurements. Although this method is often encountered in literature, the experimental apparatus needed is in general only poorly described. As Li and its alloys are very reactive substances, many parameters like the materials used for the electrochemical cell, cell geometry, establishment of O2- and H2O-free atmosphere, etc. are all important factors for a successful measuring device. Therefore, an instrumental setup for coulometric titrations combined with EMF measurements is presented in detail, covering the general and the electronic setup used, as well as the structure of the electrochemical cell. The apparatus is validated with two measurements conducted in the Li-Sn system, which are further compared with literature data.
[en] A new phenothiazine derivatives of an ionic small molecules were synthesized and its photo- and electrochemical properties were evaluated. The compounds NPzN and PPzP exhibits good thermal stabilities and shows positive solvatochromism upon increasing the polarity of the solvents. The single-component electroluminescence devices were fabricated from solution by incorporating both the emitters. Light-emitting electrochemical cell devices exhibited green color electroluminescence for both the compounds with the CIE coordinates of (0.28, 0.43) and (0.32, 0.41). These results indicate that phenothiazine derivatives have a promising prospect in the application of solution processed green LECs.
[en] By applying a DC electrical bias to a central graphene gate electrode, which separated the anode and the cathode in an electrochemical cell, we controlled the external cell's current, Icell, electrically. By irradiating the cell with modulated light intensity, we obtained an AC open-circuit response. The optically induced open-circuit AC voltage could be tuned by the DC electrical bias. Such findings suggest novel methods to control and monitor ion currents in electrochemical cells
[en] Electronic logic gates are the basic building blocks of every computing and micro-controlling system and typically require the integration of several switching elements. Ion circuits are much slower than their electronic counterpart; yet combining chemistry or bio chemistry with digital aspects is an intriguing concept. Here we demonstrate ion-XOR and ion−OR gates with two electrochemical cells without pre-ion separation. The cells were modified to include a third, permeable and conductive mid electrode (the gate), which was placed between the anode and cathode. Key to our demonstration is the use of small biasing gate power with respect to the circuit's power output. The effect is reversible and a demonstration of self-powered ion circuitry. - Highlights: • Self-powered ion-logic gates. • Metallic and porous gate electrodes within electrochemical cells. • Controlling the cell's current and voltage via the gate potential.
[en] The nuclear industry, through the application of electrolysers, can provide a solution to energy shortage with its competitive cost and can be one of the major future sources of hydrogen production with zero carbon emission. In addition, development of complementary, yet critical processes for upgrading or detritiation of the heavy water in the nuclear industry can be advanced with the application of electrolysers. Regardless of the technology, the electrolyser's development and application are facing many technical challenges including radiation and catalysis. In this paper, three main types of electrolysers are discussed along with their advantages and disadvantages. Proton Exchange Membrane (PEM) electrolysers look promising for hydrogen (or its isotopes) production. For this reason, Atomic Energy of Canada Limited (AECL) in collaboration with Tyne Engineering has started design and fabrication of PEM electrolysers with more than 60 Nm3/hr hydrogen production capacity for the application in nuclear industry. This electrolyser is being designed to withstand high concentrations of tritium. (author)
[en] The aim of this work is to analyze the efficiency of titania nanotubes acting as anode for lithium-ion batteries. The titania nanotubes has been obtained using an anodization process in a ethylene glycol solution, containing ammonium fluoride and a small quantity of water. After a heat treatment, needed to crystallize the material in the anatase form, the nanotubes has been analyzed in their performance as anode in a Li-ion battery. Structural and morphologic characterization of the titania nanotubes have been studied using XRD and SEM analysis, while the galvanostatic cycles has been collected in order to examine the electrochemical performance as electronic material. Finally, a comparison of the electrochemical performance between our samples and commercial nanostructured titanium oxide, has been made, obtaining that the TiO2 nanotube electrodes treatmen reduces the overall cell voltage and provides good retention capacity on cycling and higher capacity at all used C-rate.
[en] A simple cost-effective wet synthesis route has been proposed for synthesis of Na2Ti6O13, which is an efficient anode material that can be used for 1–3 volt batteries. The material has been synthesized by sonochemical route, which offers two distinct features: (1) energy-savvy (green) synthesis by significantly lowering the final calcination temperature and duration, and (2) formation of uniform and nano-scale particles suitable for battery application. The sonochemical synthesis was carried out at 20 kHz–500 W by applying sonication for 30 min at 25 ℃, using precursors (NaOH:TiO2 ) in a molar ratio of 6:1 followed by calcination at 750 ℃ for 1 h in air. This material showed excellent reversible electrochemical performance (up to 93% retention) and offers reversible capacity around 40 mAh g-1 acting to be 0.82 V anode for Na-ion battery. (author)
[en] The corrosion characteristics of five permanent mould magnesium alloys were studied. Two contained aluminum (AZ91D and AZ91E) and three contained zinc as the primary alloying element (ZA104 (Zn 10%, Al 4%), ZAC and ZACS). ZAC contained a small amount of calcium and ZACS contained small amounts of calcium and strontium. Two techniques were used in this study, namely 1) scanning reference electrode technique (SRET) and 2) electrochemical noise (EN). The test solution for each case was 5% NaCl saturated with Mg(OH)2 at room temperature. According to the EN measurements, the corrosion rate of AZ91D was the lowest followed by AZ91E, ZACS, ZAC and ZA104. The EN measurements showed that both the frequency and magnitude of current transients were much higher for the zinc based alloys than for the aluminum based alloys. The SRET measurements illustrated that localized corrosion occurred more frequently on the ZA104 sample than on the AZ91D sample. It seemed that increasing the level of zinc and lowering the level of aluminum relative to the levels in AZ91D does not improve corrosion resistance. (author)
[en] Synchrotron-based Compton scattering imaging has visualized the interior of a battery under in situ and operando conditions. Results of studies on Compton scattering imaging using synchrotron high-energy X-rays are reported. The technique is applied to a discharging coin cell, and the intensity of Compton scattered X-rays from the inside of the cell has been measured as a function of position and time. The position–time intensity map captures the migration of lithium ions in the positive electrode and reveals the structural change due to the volume expansion of the electrode. This experiment is a critical step in developing synchrotron-based Compton scattering imaging for electrochemical cells at a product level