Charge nickel hydroxides

The applicability of positron lifetime spectroscopy for the characterization of the partly charged nickel hydroxide was investigated [90]. The positron lifetime spectra of 8-Ni(OH)2/j8-NiOOH systems were presented. Three different parts of the annihilation curves were observed and identified. 

BAR/RAN] Barnard, R., Randell, C. F., Tye, F. L., Studies concerning charged nickel hydroxide electrodes. I. Measurement of reversible potentials, J. Appl. Electrochem., 10, (1980), 109-125. Cited on pages 118, 389. 

During charge, nickel hydroxide, Ni(OH)2, is converted to a higher-valence oxide,... 

Studies concerning charged nickel hydroxide electrodes part III. Reversible potentials at low states of charge. /. Elec-troanal. Chem., 119, 17-24. 

Electrodes. A number of different types of nickel oxide electrodes have been used. The term nickel oxide is common usage for the active materials that are actually hydrated hydroxides at nickel oxidation state 2+, in the discharged condition, and nickel oxide hydroxide [12026-04-9] NiO OH, nickel oxidation state 3+, in the charged condition. Nickelous hydroxide [12034-48-7J, Ni(OH)2, can be precipitated from acidic solutions of bivalent nickel... 

However, it can undergo self-reductive dissolution (loss of active material) accompanied by oxygen evolution [349]. The active material of the positive electrode (in pocket plate cells) consists of nickel hydroxide mixed with small additions of cobalt and barium hydroxides to improve the capacity and charging/discharging performance and graphite to improve conductivity [348]. 

Ni(lll), corresponds to about 4.0 electrons per nickel surface atom. This value is substantially smaller chan that reported by Beden et al. who estimated that four to five monolayers of (presumably divalent) nickel hydroxide were formed just prior to che onset of the redox-peak based on voltammetric measurements conducted at 0.05 V.s According to Ariva and coworkers plots of log(ig p versus log(v), where i, represents the current obtained in the plateau region during che first scan in the anodic direction and i/ is the potential scan rate, are linear over the range 10 < u < 200 mV.s Therefore the much larger charge observed by Beden et al. cannot be attributed to differences... 

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