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CuCl2 crystallizes in the tetragonal P4/mmm space group. The structure is two-dimensional and consists of one CuCl2 sheet oriented in the (0, 0, 1) direction. Cu2+ is bonded in a square co-planar geometry to four equivalent Cl1- atoms. All Cu–Cl bond lengths are 2.26 Å. Cl1- is bonded in a linear geometry to two equivalent Cu2+ atoms.
Results are reported from SDCI and CPF ab initio computations for the ground and low-lying states of CuF2 and CuCl2. A large Gaussian basis set with functions up to the g level is employed, and the results are presented in tables and characterized in detail. Particular attention is given to the bond distances and force constants for the ligand-field states and the bond distances for the charge-transfer states. Good agreement is obtained between the CPF and SDCI values and with published experimental data.
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Cu2WS4(CuCl2)2 crystallizes in the tetragonal I4/mmm space group. The structure is one-dimensional and consists of two Cu2WS4 ribbons oriented in the (0, 0, 1) direction and two CuCl2 ribbons oriented in the (0, 0, 1) direction. In each Cu2WS4 ribbon, there are two inequivalent W6+ sites. In the first W6+ site, W6+ is bonded in a body-centered cubic geometry to eight equivalent S2- atoms. All W–S bond lengths are 2.56 Å. In the second W6+ site, W6+ is bonded in a body-centered cubic geometry to eight equivalent S2- atoms. All W–S bond lengths are 2.56 Å. Cu+1.50+ is bonded in a 4-coordinate geometry to four equivalent S2- atoms. All Cu–S bond lengths are 2.40 Å. S2- is bonded in a 2-coordinate geometry to two W6+ and two equivalent Cu+1.50+ atoms. In each CuCl2 ribbon, Cu+1.50+ is bonded in a square co-planar geometry to four equivalent Cl1- atoms. All Cu–Cl bond lengths are 2.31 Å. Cl1- is bonded in a bent 120 degrees geometry to two equivalent Cu+1.50+ atoms.
Four different grades of pitch-based graphite fibers (Amoco P-55, P-75, P-100. and P-120) were intercalated with each of four different intercalates: bromine (Br2), iodine monochloride (ICl), copper (II) chloride (CuCl2), and nickel (II) chloride (NiCl2). The P-55 fibers did not react with Br2 or NiCl2, and the P-75 did not react with NiCl2. The stability of the electrical resistance of the intercalated fibers was monitored over long periods of time in ambient, high humidity (100 percent at 60 C), vacuum (10 to the -6 torr), and high temperature (up to 400 C) conditions. Fibers with lower graphitization form graphite intercalation compounds (GIC's) which are more stable than those with higher graphitization (i.e., P-55 (most stable) greater than P-75 greater than P-100 greater than P-120 (least stable). Br2 formed the most stable GIC's followed in order of decreasing stability by ICl, CuCl2, and NiCl2. While Br2 GIC's had the most stability, ICl had the advantages of forming GIC's with slightly greater reduction in resistance (by about 10%) than Br2, and the ability to intercalate P-55 fiber. Transition metal chlorides are susceptible to water vapor and high temperature. The stability of fibers in composites differs.
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SnO2 buffer layers of different thickness were deposited onto TEC 15 Fluorine doped tin oxide coated glass substrates using rf magnetron sputtering. The buffer layers were then incorporated into Cu-doped CdSeTe/CdTe devices using a range of CdCl 2 activation treatments and CuCl2 annealing temperatures to determine the effects of buffer layer thickness on device performance. Results show that all devices fabricated with thinner buffer layers resulted in much better J - V characteristics than their thicker counterparts. This was mainly due to a reduced open-circuit voltage (Voc) when using thicker buffer layers. The best device produced a conversion efficiency of 16.59%, fill factor of 71.62%, Jsc of 28.44 mA/cm 2 and Voc of 814.23 mV.
Tracing sources of contamination, including potentially toxic elements (PTEs), has historically been achieved through sampling and analysis of soil or biota, which are labor-intensive, costly, and destructive methods. Thus, availability of a non-destructive in situ remote sensing method for monitoring metals deposited in biota is of great interest. Laser-induced fluorescence (LIF) is an emerging spectroscopic and imaging technique that documents changes in molecular energy level in plants as a biological response to metal contamination. For a proof-of-concept study and preliminary experiment, moss was selected for experimentation due to its long history of use in tracing atmospheric deposition of PTEs. Consecutive treatments of copper chloride (CuCl2) were administered to three moss samples, simulating wet deposition every 48 h over 10 days until reaching cumulative Cu concentrations of 2.690 to 8.075 μmol/cm2. While these Cu amounts are above environmentally relevant concentrations, they allowed the best conditions for testing and fine tuning of the imaging and data processing protocols presented in this paper. Moss fluorescence was induced using both 532 nm green and 355 nm UV lasers. A CMOS camera captured images of the LIF response, and red–green–blue (RGB) decimal code values were extracted for each pixel in the images, and pixel densities of color channels from treated and untreated moss samples were compared. Results show a shift towards lower color decimal codes corresponding to increased Cu concentration. We developed and contrasted multiple quantitative analyses of color distributions and demonstrated that LIF shows great promise for remote sensing of Cu accumulation in moss at μmol/cm2 levels. Though currently, the method would be limited to highly toxic sites, it illustrates the possibility and provides a framework for development of higher-sensitivity methods to detect nmol/cm2 that are viable for urban contamination level monitoring.
Transitioning from fossil-fuels to renewable energy sources is a critical goal of greenhouse gas re-duction and climate control. Major improvements have made wind and solar power increasingly cost-competitive with fossil fuels. However, the inherent intermittency of renewable power sources such motivates pairing these resources with energy storage. Electrochemical energy storage in batteries is widely used in many fields and increasingly for grid-level storage, but current battery technologies still fall short of performance, safety, and cost. This review focuses on sodium metal halide (Na-MH) batteries, such as well-known Na-NiCl2 batteries, as a promising solution to safe and economical grid-level energy storage. Important features of conventional Na-MH batteries are discussed, and recent literature on the development of intermediate temperature, low-cost cathodes for Na-MH batteries is highlighted. By employing lower cost metal halides (e.g. FeCl2, ZnCl2, and CuCl2, etc.) in the cathode and operating at lower temperatures (e.g. 190 °C vs. 280 °C), new Na-MH batteries have the potential to offer comparable performance at much lower overall costs, providing an exciting alternative technology to enable widespread adoption of renewables plus storage for the grid.
Experiments were done with a molten-salt catholyte (initially CuCl2 in AlCl3-NaCl) separated from molten Na by beta alumina. The open-circuit reduction potentials were 4.3 and 3 volts for Cu++ and Cu+, respectively. High polarization and nonrechargeability characterized the cell's operation. The cell's ohmic resistance during discharge was higher than what would be expected from only the ionic resistance of the beta-alumina.
A problem encountered in the analysis of amino acids in chemical evolution experiments and in extracts of meteorites is the large number present. A method for selectively destroying the alpha-amino acids, with only the beta- and gamma-amino acids remaining in the solution, is described. The amino acids used were racemic, with one milliliter of solution containing 0.0000025 mol of each acid irradiated in a 1-cm quartz cell having 254-nm monochromatic light in the presence of CuCl2. Excess H2S was added to precipitate the Cu (2+) as CuS. A gas chromatographic analysis was used to observe that irradiation with 254-nm light in the presence of Cu (2+) destroyed all the amino acids except the beta and the gamma types. It is concluded that with such a procedure, complex mixtures of amino acids can be simplified to make identification by GC mass spectrometry easier.
Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 Wh/kg theoretical). Energy densities in excess of 180 Wh/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Researchers at JPL are evaluating various new cathode materials for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far studies have focused on alternate metal chlorides such as CuCl2 and organic cathode materials such as tetracyanoethylene (TCNE).
Since the fall of 1986, cirrus clouds were observed with backscatter cross sections ranging from less than 1 x 10(exp -7) to 4.2 x 10(exp -5)m/sr, optical thicknesses ranging from less than .003 to greater than 2.7, and bulk average backscatter phase functions from .02 to .065/sr. Cirrus cloud structures were recorded ranging in vertical extent from 0.1 to 8 km, having horizontal scales from 10's of meters to 266 km, and exhibiting aspect ratios of from 1:5 to 1:100. The altitude relationship between cloud top and bottom boundaries and the optical center of the cloud is influenced by the type of formation observed. Cirrus morphology and generation processes appear to be related to the wind field. The high spectral resolution lidar (HSRL) was adapted to the task of cirrus cloud optical property measurement. The HSRL data reported were collected with the CuCl2 transmitter producing 50 mW of output power, achieving eye safe, direct optical depth and backscatter cross section measurements with 10 minute averaging times.
The reaction of the surfaces of the new high-temperature superconductor YBa2Cu3O(7-x) with nonaqueous halogen solutions is investigated, and the species formed in the reactions are identified. Treatment of films with HF/EtOH (EtOH = HI in absolute ethanol) results in the formation of an oxyfluoride with Y:Ba:Cu relative concentrations of 1:4:3. Results of X-ray photoelectron spectroscopy of HF-treated films are consistent with the formation of CuF, a compound which does not exist in bulk form. Treatment of films with HCl/EtOH results primarily in the formation of BaCl2, with smaller amounts of YCl3, CuCl, and CuCl2. Treatment with Br2/EtOH or HBr/EtOH results in the formation of YBr3, BaBr2, and CuBr with relative concentrations of 1:4:3.
Various high energy density rechargeable batteries are being considered for future space applications. Of these, the sodium-sulfur battery is one of the leading candidates. The primary advantage is the high energy density (760 W h/kg theoretical). Energy densities in excess of 180 W h/kg have been realized in practical batteries. More recently, cathodes other than sulfur are being evaluated. Various new cathode materials are presently being evaluated for use in high energy density sodium batteries for advanced space applications. The approach is to carry out basic electrochemical studies of these materials in a sodium cell configuration in order to understand their fundamental behaviors. Thus far, the studies have focussed on alternative metal chlorides such as CuCl2 and organic cathode materials such as TCNE.
Preliminary fundamental investigations aimed at evaluating sodium metal chloride systems for future aerospace applications are described. Since the sodium metal chloride systems are relatively new, the approach has been to characterize their fundamental properties in order to understand their limitations. To this end, a series of fundamental electrochemical investigations have been carried out, the results of which are reported here. The metal chloride cathodes show high exchange current densities which corroborate their good reversibility in a battery application. The reduction mechanisms appear to be complex and involve multielectron transfer steps and intermediates. Such intermediates in the reaction mechanism have already been identified in the case of FeCl2. Similar mechanisms may be operative in the case of NiCl2. CuCl2, however, exhibits a second relaxation loop in the impedance plot at low frequencies and also a sloping discharge curve, unlike FeCl2 and NiCl2, which may indicate the existence of monovalent copper in the reduction mechanism.
Fundamental electrochemical studies on three candidate materials, i.e., FeCl2, NiCl2, and CuCl2, were carried out using various techniques, such as cyclic voltammetry, linear polarization, potentiodynamic polarization, and ac impedance. These studies were aimed at identifying various rate processes in the reduction, elucidating the reaction mechanisms, and determining the kinetic parameters for the reduction. The limitations in the performance of these cathode materials in high power density applications were also examined. Finally, recommendations were made from these studies for the selection of a candidate system among these materials for future NASA applications.
Following the disclosures by Coetzer et al. on the use of transition metal chlorides in chloroaluminates as alternate cathodes to sulfur in rechargeable sodium batteries, several laboratories, including the Jet Propulsion Laboratory, focused their attention on these systems. These systems have certain distinct advantages over sodium-sulfur batteries such as increased safety, inherent overcharge capability, and lower operating temperatures. Two systems, i.e., Na/FeCl2 and NaNiCl2, were developed extensively and evaluated in various applications including electric vehicles and space. Their performance has been very encouraging and warrants a detailed fundamental study on these cathodes. At the Jet Propulsion Laboratory a program was initiated two years back to understand the electrochemical behavior of FeCl2 and NiCl2, and to identify and evaluate other transition metal chlorides of promise. The initial efforts focused on the methods of fabrication of the electrodes and their electrochemical characterization. Subsequent studies were aimed at establishing the reaction mechanism, determining the kinetics, and identifying the rate-limiting processes in te reduction of metal chloride cathodes. Nickel chloride emerged form these studies as the most promising candidate material and was taken up for further detailed study on its passivation- a rate limiting process-under different experimental conditions. Also, the feasibility of using copper chloride, which is expected to have a higher energy density, has been assessed. On the basis of the criteria established from the voltammetric response of FeCl2, NiCl2, and CuCl2, several other transition metal chlorides were screened. Of these, molybdenum and cobalt appear promising.