Infrared characterization of turbostratic α- and well crystallized α*-cobalted nickel hydroxides

The Outcome of Cobalt in the Nickel–Cobalt Oxyhydroxide Electrodes of Alkaline Batteries

“…Thus, the bending over of the capacity trace as a function of the cycle number most likely results in the sum of two opposite e!ects: One due to the in situ formation of the mixed Ni/Co -type phase leading to an increase in capacity and the other due to the lesser conductivity of the residual nickel hydroxide grains from the conductive cobalted phase leading to a decrease in capacity. Let's now discuss these results in light of previous "ndings made by Delmas et al (11,12) and Gautier (13). Using mixed nickel/cobalt DLH-type phases as electrodes, these authors demonstrated that extended cycling ( '70 cycles) down to a cuto!…”

“…Thus we deduced that the 1.2-V additional anomaly that developed upon cycling is the electrochemical signature of the */ phase transformation. The */ redox couple was intensely studied by Delmas et al (11,12) and Gautier (13) because of its high initial capacity (up to 350 mAh/g) that, unfortunately, could not be sustained over numerous cycles because of the progressive irreversible transformation of -Ni(OH) into -Ni(OH) upon cycling, which is the opposite of what we initially experimentally observed. These results raise several questions regarding the mechanism by which this */ phase transformation occurs and the role played by Co(OH) in this transformation.…”

“…Thus, both electrochemical and X-ray data support that the cycledriven growth of the phase is directly correlated to the amount of cobalt within the NOE electrode. Knowing from the work of Delmas et al (5,11,12) that cobalt ions are prone to stabilize the *-Ni \V Co V (OH) phase, we hypothesized in the present case the growth upon cycling of a coprecipitate Ni/Co hydroxide.…”

Comparative structural and electrochemical study of high density spherical and non-spherical Ni(OH)2 as cathode materials for Ni–metal hydride batteries

“…The couple bands at about 1470 cm −1 and 1380 cm −1 in both IR spectra can be assigned to c o vibration of the adsorbed CO 2 molecules due to the open system used for synthesis [38]. The band at about 1125 cm −1 corresponds to the vibration of SO 4 2− [39].…”

Fabrication of Novel Titanium‐supported Ni‐Sn Catalysts for Methanol Electro‐oxidation

“…Some Ni-based bimetallic alloys including Ni-Cd, Ni-Fe, Ni-Zn, and Ni-Cu were investigated, which present higher electrocatalytic activity for methanol oxidation. [11][12][13][14] Skowronski 15 reported the preparation of nickel foam and nickel foam-based composite electrodes and investigated their electroactivity for methanol oxidation. Nickel impregnated zeolite-modified electrodes by mixing Ni-silicalite-1 with conducting carbon black were fabricated by Khalil and their electrocatalytic activity was found to depend on the nickel content.…”