Composite grids copper

Many concepts were developed to overcome one of the main drawbacks of the lead-acid system the heavy supporting lead structures (grids, connectors, etc.). Lead foam [89], lead-plated carbon rods [90], electroplated vitreous carbon [91], flexible-graphite grids [92], or graphite foams [93] were tested, also lead-plated materials like titanium [94], Ebonex [95], copper mesh [96], polymeric structures [97], polymer foam [98], or glass fiber mesh [99]. Warlimont and Hofmann [100] describe the development of multilayer composite grids. 

There is no question that the development and commercialization of lithium ion batteries in recent years is one of the most important successes of modem electrochemistiy. Recent commercial systems for power sources show high energy density, improved rate capabilities and extended cycle life. The major components in most of the commercial Li-ion batteries are graphite electrodes, LiCo02 cathodes and electrolyte solutions based on mixtures of alkyl carbonate solvents, and LiPF6 as the salt.1 The electrodes for these batteries always have a composite structure that includes a metallic current collector (usually copper or aluminum foil/grid for the anode and cathode, respectively), the active mass comprises micrometric size particles and a polymeric binder. 

Fig. 26. High -resolution transmission electron microscopy (HRTEM) image of perfluoropoly-ether-modified G3 PPI dendrimers containing Pd metal nanoclusters prepared on aholey carbon copper grid by evaporation of a dilute solution of the dendrimer composite. Reprinted with permission from Ref. 100 Copyright 2000 WUey-VCH...

Figure 4. Inhomogeneity of silica-aluminas prepared by various methods. A series of 17 commercial samples of silica-aluminas from seven different producers was submitted to microanalysis. All of them showed considerable fluctuations of composition at the scale of several tens of nanometers to several micrometers. These samples were prepared by coprecipitation or by the sol-gel method. It is not known whether some of these samples were prepared from alkoxides. Smaller but significant fluctuations at the micrometer scale were also observed for two laboratory samples prepared from alkoxides. The samples were dispersed in water with an ultrasonic vibrator. A drop of the resulting suspension was deposited on a thin carbon film supported on a standard copper grid. After drying, the samples were observed and analyzed by transmission electron microscopy (TEM) on a JEOL-JEM 100C TEMSCAN equiped with a KEVEX energy dispersive spectrometer for electron probe microanalysis (EPM A). The accelerating potential used was 100 kV.

Fig. 2 shows how the aminoday -metal nanoparticle composites form clear transparent solutions in water. The solutions are pink and yellow for Au and Ag respectively and dark brown in the cases of both Pt and Pd. The reddish-brown colour observed for Au-clay nanoparticle composites immediately after the addition of NaBH4 changed to pink with time. The solutions exhibit characteristic piasmon bands for the Au- and Ag-day suspensions at 520 nm and 410 nm respectively as shown in Fig. 3. In the cases of Pt and Pd, the characteristic absorption band for the precursor s around 260 to 280 nm was absent thereby confirming the formation of Pt and Pd nanoparticles. 7,18 TEM images of the aminoday-metal nanoparticle composites deposited on a carbon coated copper grid are shown in Fig. 4. The histograms show the average particle sizes to be around 3.5 and 5 nm respectively in the cases of Au and Ag nanoparticles. We could see the layered arrangements in the cases of Pt and Pd with the interspacing of 1.5 nm commensurate with the bilayer arrangement of aminoclays (see top right inset of Fig. 4b).

Electroless deposition can successfully be used in the production of various composite materials useful for the electronics applications. The examples include silver-coated copper or nickel particles, used in screen printing,43 gold-coated nickel powders, silver and/or palladium-coated polymers or glass powders used in ball grid array, etc. 

As we know, some high Tc superconductors such as YBCO easily degrade due to the moisture in the air. This means that we have to reduce the exposure time of the sample to air and avoid water in the whole preparation process. When the sample is dedicated for cross-section observation, it is recommended to deposit gold or silver directly in situ) on the surface of the film in order to protect it from degradation. Copper grids are often used for support of samples. However, in order to check the chemical composition of high superconduc-... 

The particle size and composition of the dispersed phase of the colloidal dispersions were studied by transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis and photoluminescence (PL) spectroscopy. The TEM experiments were carried out on a LEO-906 device. The samples were obtained by placing a drop of the colloidal solution in toluene on TEM copper grid coated with a thin layer of carbon and evaporated in air at room temperature. XRD patterns of powders were obtained by a diffractometer HZG 4A using CuKa radiation. The UV-vis spectra of the colloidal dispersions were recorded using Cary 500 Scan UV-VIS-NIR spectrophotometer with a 1-cm quartz cell. The PL spectra were recorded using a SFL-1211A spectrofluorimeter. 

FIGURE 6.16 Composite copper-cored lead grid. 

Figure 4.9 TEM micrographs recorded on a platinum shadowed replica prepared by FFET. (a) Sample prepared on 5 % dispersion of overbased calcium didodecylbenzene sulfonate in dodecane. Spherical nanoparticles of 10 nm diameter are easily visible, (b) Extractive replica prepared on the same dispersion. (c) X-ray analysis of the selected area (black circle) reveals the composition of the particles (Ca, S, O) corresponding to the sulfonate. The presence of Pt is due to the shadowing layer and copper to the copper support grid, (d) Radial distribution functions (from EXAFS studies) uncorrected from phase shifts obtained on caldte, and two OCABS dispersions in oil. The presence of a single peak corresponding to the first Ca-0 distance points out the amorphous structure of the mineral part of the OCABS particles...

Samples of water were collected upstream of Manaus on the Rio Negro to identify DOC and determine its inorganic composition. Whole mounts of unfixed organic material (DOC) were prepared for electron microscopy by pipetting 10 OL of water sample onto Formvar and carbon-coated copper grids. After allowing the water to evaporate ofl the grids were analyzed by TEM and EDS. 

In order to measure the field emission characteristics, the Cgo/CNT composite, which was produced by the drawing process, was mounted on a copper grid using an adhesive and a silver paste and was used as an electron emission source (Fig. 14.21). Six readings of the emission current (I) in a sample for the applied voltage (V) were measured in a high vacuum chamber with a base pressure of approximately 6.5 x 10 ° Pa. The distance between the electrodes was fixed at 200 /im using a mica spacer. 

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