An electrolysis-cell design for simultaneous electrochemical reduction of CnormalO2 and normalH2O to make syngas (CO+normalH2) at room temperature (25°C) was developed, based on a technology very close to that of proton-exchange-membrane fuel cells (PEMFC), i.e., based on the use of gas-diffusion electrodes so as to achieve high current densities. While a configuration involving a proton-exchange membrane (Nafion) as electrolyte was shown to be unfavorable for CnormalO2 reduction, a modified configuration based on the insertion of a pH-buffer layer (aqueous KHCnormalO3 ) between the silver-based cathode catalyst layer and the Nafion membrane allows for a great enhancement of the cathode selectivity for CnormalO2 reduction to CO [ca. 30mA∕cm2 at a potential of −1.7to−1.75V vs SCE (saturated-calomel reference electrode)]. A CO∕normalH2 ratio of 1∕2 , suitable for methanol synthesis, is obtained at a potential of ca. −2V vs SCE and a total current density of ca. 80mA∕cm2 . An issue that has been identified is the change in product selectivity upon long-term electrolysis. Results obtained with two other cell designs are also presented and compared.

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Electrochemical oxidation of carbonate esters at the Li(x)Ni(0.5)Mn(1.5)O(4-δ)/electrolyte interface results in Ni/Mn dissolution and surface film formation, which negatively affect the electrochemical performance of Li-ion batteries. Ex situ X-ray absorption (XRF/XANES), Raman, and fluorescence spectroscopy, along with imaging of Li(x)Ni(0.5)Mn(1.5)O(4-δ) positive and graphite negative electrodes from tested Li-ion batteries, reveal the formation of a variety of Mn(II/III) and Ni(II) complexes with β-diketonate ligands. These metal complexes, which are generated upon anodic oxidation of ethyl and diethyl carbonates at Li(x)Ni(0.5)Mn(1.5)O(4-δ), form a surface film that partially dissolves in the electrolyte. The dissolved Mn(III) complexes are reduced to their Mn(II) analogues, which are incorporated into the solid electrolyte interphase surface layer at the graphite negative electrode. This work elucidates possible reaction pathways and evaluates their implications for Li(+) transport kinetics in Li-ion batteries.

The hydride transfer mechanism of the NAD model compound 1 to its 1,4-NADH derivative 3 [Eq. (1)] is proposed to be a consequence of the critical role of the carbonyl group of the amide to coordinate to the ring-slipped η - to η -Cp*Rh metal center of the catalyst [Cp*Rh(bpy)H] , prepared in situ from 2, while a steric effect of a substituent in the 3 position, for example, C(O)NEt , was found to totally inhibit this regioselective reduction. bpy=2,2'-bipyridine, Cp*=C Me , OTf=trifluoromethanesulfanate.

A baseline cell chemistry was identified as a carbon anode, LiNi 0.8 Co 0.2 O 2 cathode, and diethyl carbonate-ethylene carbonate LiPF 6 electrolyte, and designed for high power applications. Nine 18650-size advanced technology development cells were tested under a variety of conditions. Selected diagnostic techniques such as synchrotron infrared microscopy, Raman spectroscopy, scanning electronic microscopy, atomic force microscopy, gas chromatography, etc., were used to characterize the anode, cathode, current collectors and electrolyte taken from these cells. The diagnostic results suggest that the four factors that contribute to the cell power loss are solid electrolyte interphase deterioration and nonuniformity on the anode; morphology changes, increase of impedance, and phase separation on the cathode; pitting corrosion on the cathode current collector; and decomposition of the LiPF 6 salt in the electrolyte at elevated temperature.

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Values for the lithium ion transference number (t + 0 ) are reported for the solid polymer electrolyte system poly(ethylene oxide) (PEO) complexed with Li(CF 3 SO 2 ) 2 N (LiTFSI). t + 0 ranges from 0.17 ( 0.17 to 0.60 ( 0.03 in the salt concentration (c) region of 742 to 2982 mol/m 3 at 85 °C. The concentration dependence of t + 0 and the molar ionic conductivity (Λ) are shown to be in good agreement with a free volume approach over the salt-rich composition range investigated. The present t + 0 results were obtained using an electrochemical technique based on concentrated solution theory. This experimentally straightforward method is herein demonstrated to give accurate results for a highly concentrated SPE system, without relying on any dubious simplifications regarding the state of the electrolyte.