Copper Coated LiCoO2 Particles For Water Friendly Electrodes In Li-Ion Batteries

Metal oxide-based coatings have been applied on LiCoO2 particles in order to allow the use of water as solvent in the manufacturing process of the cathodes for Li-ion batteries. The coating has been obtained by oxidation of a metallic layer deposited on the particles with electroless deposition. The treatment allowed the deposition of a copper (II) oxide layer on the particles as shown by XPS analysis. SEM investigation demonstrates that particles morphology is unchanged after the plating process. The treatment does not The electrodes manufactured with the coated powders of active material show an increased resistance to chemical decomposition in aqueous environment, as shown by electrochemical performances assessment, evaluated by means of galvanostatic cycling in coin cells. Capacity vs. cycles charts show that the stability of the cycling capacity is improved with respect to a cathode made of uncoated LiCoO2 particles and PVDF latex as binder

PVDF latex as a binder for positive electrodes in lithium-ion batteries

The present work shows a way to develop an industrial organic solvent-free process for lithium-ion battery electrodes manufacturing. The process uses a water-based slurry to cast the electrodes, using poly vinylidene-fluoride (PVDF) as a polymeric binder. The use of aqueous PVDF latex as a binder in positive electrodes is of difficult integration in existing production lines due to the low stability of lithium cobalt oxide (LiCoO2) in an aqueous environment. The use of electroless plating solves this issue by coating LiCoO2 particles with a copper-based layer stable to water. The presence of copper on the surface of the powders is confirmed by means of SEM, XRF and conductivity measurements of the powders. Electrochemical characterization of the electrodes has been carried out with cycling tests in coin cells, confirming the cycling stability during charge/discharge cycles. Cycling performances of the water-based cathodes containing coated active material particles are comparable to a reference NMP-based cathode, while uncoated particles show a sensibly lower capacity retention during cycling. The possibility of up-scaling the metallization process has been tested with the use of a semi-industrial pilot filter dryer

Surface modification and electrochemical metallization of advanced polymers for energy application

Combination of polymeric and metallic layers in a single device is becoming inevitable for applications in an increasing number of fields, including alternative energy. A basic product consisting in a metal-polymer (partially fluorinated) bilayer can be simply obtained by two steps. The first step of the process consists in surface modification of the polymer by plasma treatment, whose main effect is to increase the wettability. The increase of wettability by water is crucial for the second step of the process, which consists in aqueous based electroless deposition of metals. As revealed by cross cut and bending tests, adhesion between the metallic and polymeric layer is excellent. Given the suitable transparency and weathering resistance of Halar® ECTFE, the application of this process for production of solar concentrator mirrors is being considered. Light reflection properties and UV ageing were determined for this purpose

The effects of anesthesia, muscle paralysis, and ventilation on the lung evaluated by lung diffusion for carbon monoxide and pulmonary surfactant protein B

BACKGROUND:: An increased alveolar-arterial oxygen tension difference is frequent in anesthetized patients. In this study, we evaluated the effect on the lung of anesthesia, muscle paralysis, and a brief course of mechanical ventilation.METHODS:: Lung diffusion for carbon monoxide (DLCO), including pulmonary capillary blood volume (Vc) and conductance of the alveolar-capillary membrane (DM), and pulmonary surfactant protein type B (a marker of alveolar damage) were measured in 45 patients without pulmonary disease undergoing extrathoracic surgery.RESULTS:: Anesthesia, muscle paralysis, and mechanical ventilation led to impairment of gas exchange, with a reduction of DLCO values immediately after anesthetic induction due to a concomitant reduction of both DM and Vc. While changes in DM were due to the reduction of lung volume, changes in Vc were not limited to volume loss, since the Vc/alveolar volume ratio decreased significantly. Although DLCO and its components decreased immediately after induction, none of the values decreased further at 1 and 3 hours. Surfactant protein type B, however, was unchanged immediately after anesthesia but increased at 1 hour after induction and further increased after 3 hours of anesthesia. The level of alveolar damage correlated with the reduction of lung perfusion and lung dynamic strain (i.e., ratio between tidal volume and end-expiratory lung volume).CONCLUSIONS:: A brief course of anesthesia and controlled ventilation leads to: (1) alveolar damage, which is correlated with lung strain and perfusion, and (2) impaired gas exchange mainly due to volume loss but also to reduced aerated lung perfusion

Ink-jet printing and electrodeposition for the production of free standing and polymer supported micronet electrodes

A study on optimization of Ink-Jet printing parameters, in terms of drop spacing, operative voltage and waveform, metallic line width and spacing is presented, with the aim of producing flexible Transparent Conducting Electrodes (TCEs). Silver micronets were produced by Ink-Jet printing on PET films, to obtain polymer supported transparent electrodes; preliminary studies were also performed on the production of freestanding electrodes, by electrodeposition on the printed micronets. The study reveals that PET supported transparent conductive electrodes can be obtained by ink-jet printing, having improved performances with respect to Indium Tin Oxide (ITO) in terms of resistivity and resistance to bending: no cracking or delamination was observed during bending of the micronets and resistance, measured between two points at 3 cm distance, is one order of magnitude lower for the micronets. Preliminary studies on production of freestanding meshes reveal that this process is promising and allows further reduction in electrode resistance, measured between two points at 3 cm distance, of one order of magnitude. Line width, which is the main limitation of this process, can be conformally reduced by electropolishing without causing collapse of the freestanding micronet

Assessment of cardiac resynchronization therapy response

The present study was performed to evaluate how to assess cardiac resynchronization therapy (CRT) efficacy in chronic heart failure (CHF) through clinical, echocardiographic and exercise analysis. We analyzed 41 stable CHF (NYHA III) patients with: left bundle-branch-block, ejection fraction <35%, left-ventricular dissynchrony (by tissue-Doppler), peak oxygen consumption (VO2) <16 ml/kg/min, suitable cardiac vein (by multislice computed tomography) and no anemia or kidney failure. Patients were evaluated before and after (7 +/- 3 months) CRT. Two patients died. CRT responders to none of the evaluated criteria were 19.5%. The best agreement (90%) with clinical response was obtained using the presence/absence of either left-ventricular systolic volume (LVSV) or peakVO2 response. In less severe CHF (peakVO2 12-16 ml/kg/min), peakVO2 and work-load didn't change after CRT, despite echocardiographic, ventilation/carbon dioxide relationship and clinical improvement. Echocardiography and CPET are complementary for the evaluation of CRT, but not in less severe CHF patients, where the role of CPET remain uncertain. (C) 2008 Elsevier Ireland Ltd. All rights reserved