Binary 9:1 composite hydroxides of nickel with 13 other metals were prepared by cathodic electrocoprecipitation from metal nitrate solutions and characterized by cyclic voltammetry in 1M KOH. Under these conditions, coprecipitated Ce, Fe, and La strongly catalyzed the oxygen evolution reaction. Converse]y, Cd, Pb, and Zn poisoned this reaction. The hydrogen evolution reaction was less affected by the coprecipitated metals; Ag and Pb had a catalytic effect on this reaction. Co and Mn shifted the nickel hydroxide redox potentials to more cathodic values. In contrast, Cd, Ce, Cr, Fe, La, Y, and Zn each shifted these redox potentials anodically. The coulombic efficiency of the oxidation-reduction process was substantially lowered by Ce, Fe, and La.

Electrochromic films of a series of binary composite hydroxides of nickel and other metals (in a ratio of about 1:10) were deposited cathodically from mixed nitrate solutions onto transparent, conducting substrates. Visible spectra of the composite hydroxides were generally similar to those for nickel hydroxide, itself; the reduced forms were essentially transparent and the oxidized forms exhibited a strong, broad absorption band throughout the visible region. The coprecipitated metal ions did have significant effects on the switching of the electrochromic nickel couple. The composite hydroxide with silver displayed complex electrochromic switching behavior due to the presence of an additional electrochromic silver couple which could be colored cathodically. Significantly for electrochromic window applications, coprecipitation of cerium or lanthanum improved the durability of switching of the electrochromic nickel couple.Previous investigations of the electrochromic properties of nickel hydroxide have revealed promising characteristics for smart window applications including a high coloration efficiency throughout the visible region (1-5). Electrochromic nickel hydroxide films have been prepared by anodic electrodeposition (1, 4), cathodic electrodeposition (3), and reactive rf sputtering (2, 5). There have been reports that the electrochromic response of electrodeposited nickel hydroxide films undergoes significant deterioration during coloration/bleaching cycles (3, 4). Improvements in the electrochromic switching performance may be possible by coprecipitating other metal ions into nickel hydroxide films. The performance of nickel battery electrodes has been altered by a variety of metal additives (6, 7). We have recently surveyed the electrochemistry of binary composite hydroxides formed by coprecipitating each of thirteen other metals into nickel hydroxide films (8). In the present work, we study the effect of these coprecipitated metals on the electrochromic switching of nickel hydroxide films. ExperimentalSubstrates.--Substrates were made from glass with a conductive coating of about 440 nm of fluorine-doped tin oxide (FTO) which had resistance of about 14 l~/square (Watkins-Johnson Company, Scotts Valley, California). The 0.3 cm thick glass was cut into 0.9 cm x 5.0 cm pieces with electrical contact to the FTO made through a spring clip of 0.1 mm nickel foil. Prior to use, the substrates were decreased by cleaning with detergent soap and acetone and rinsed with water. Additionally, they were anodically polarized in 10 volume percent (v/o) H2SO4 with a current of 20 mA (8.8 mA/cm 2) for 15s and then rinsed. The cleaned FTO glass substrates were immersed in distilled water until use.Film deposition.--Nickel hydroxide films were applied to the FTO-coated glass substrates by cathodic deposition from 0.01M nickel nitrate. Similarly, composite hydroxides were prepared by cathodic deposition from mixed metal nitrate solutions. First, 0.10M solutions were prepared of each of 13 other metal nitrates: Cd(NOa)2, Ce(N...

Binary 9:1 composite hydroxides of Ni with Cd, Ce, Cr, Co, Cu, Fe, La, Pb, Mg, Mn, Ag, Y, or Zn, prepared by cathodic deposition from mixed metal nitrate solutions, are characterized by cyclic voltammetry in 1 M KOH.

Zinc electrodes were cycled against segmented counterelectrodes, with the current to the individual segments of the counterelectrodes being controlled throughout cycling. The experimental results gave direct evidence that concentration cells were being established across the faces of the electrodes. Despite the existence of these concentration cells, the distribution of zinc and the rate of shape change in the cycled zinc electrodes were found to be independent of the current patterns imposed on the counterelectrode segments. However, when the separations between the counterelectrode segments were electrolyte-filled channels, the zinc electrode shape change was directly related to the size of that separation. This behavior can be explained by electrolyte flowing in the cell stack acting as the driving force for shape chang e . ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-30 to IP Vol. 134, No. 4 ZINC ELECTRODE SHAPE CHANGE 783 ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-30 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-30 to IP ABSTRACTThe electrochemical characteristics of polyvinylferrocene (PVF) was investigated for use as an electrode-active material in rechargeable batteries. Charge-discharge curves of the PVF electrodes showed excellent potential flatness and very high coulombic efficiencies in both nonaqueous and aqueous solutions. The dispersion of graphite powder in PVF was very useful for increasing the discharge rate and PVF utilization. The self-discharge rates were found to be as low as 1% in the first day. It is concluded that PVF is a promising material as an electrode-active material in rechargeable batteries.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14.35 Downloaded on 2015-03-30 to IP

Electrochromic films of binary composite hydroxides of Ni and a second metal (Cd, Ce, Cr, Co, Cu, Fe, La, Pb, Mg, Mn, Ag, Y, Zn; ratio 1:10) are cathodically deposited from mixed nitrate solutions onto fluorine‐doped tin oxide (FTO) glass substrates.