The effect of cobalt on the chemical and electrochemical behaviour of the nickel hydroxide electrode

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

“…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.…”

Nickel hydroxides and related materials: a review of their structures, synthesis and properties

“…Such materials have been described as 'interstratified phases consisting of α-and β-type structural motifs' and not simple mixtures of α-and β-Ni(OH) 2 crystals [33,41,96,97]. Rather, the presence of interstratification allows α-and β-Ni(OH) 2 domains to coexist within a single crystal.…”

“…It should be noted that vibrational spectra collected from interstratified materials contain the characteristic O−H internal stretching modes of both the α-and β-phase materials (see §4b) [33,41,96]. Moreover, it is possible to have interstratification and other types of structural disorder, such as the mixed metal, carbonate-intercalated α/β IS -Ni 0.9 Mn 0.1 (OH) 2 materials reported in Guerlou-Demourgues et al [96] or the carbonate-intercalated α/β IS -Ni 1−x Co x (OH) 2 2 , and β-Ni(OH) 2 using a Cu Kα X-ray.…”

“…X-ray diffraction parameters of α-Ni(OH) 2 calculated using the unit cell shown in figure 4 and the lattice parameters reported by Pandya et al [32]. Fewer significant digits are provided for peaks involving the crystallographic c-axis [(001), (111 [33,34]). In these sources, the Miller indices also vary by a factor of three (e.g.…”

Bi2O3 modified cobalt hydroxide as an electrode for alkaline batteries

“…To balance the positive charge on the layers, anions and water molecules get intercalated in the interlayer region resulting in an increase in the inter lamellar spacing from 4.6 to 7.6Å [22]. Layered double hydroxides (Ni-Al, Ni-Co, Ni-Mn, Ni-Zn) are extensively used as electrode materials and are known to perform better than nickel hydroxide electrodes [7,[23][24][25]. Table 1).…”