Three-component layer double hydroxides by urea precipitation: structural stability and electrochemistry

Preparation and performance of LiNi0.8Co0.2O2 cathode material based on Co-substituted α-Ni(OH)2 precursor

“…It can be seen that the diffraction pattern of the precursor has good correspondence with the patterns reported for Į-phase Ni(OH) 2 [17,19] . The (003) peak around 2ș=12° and the broad asymmetric peak at about 2ș = 32 36° are characteristic peaks for turbostratic Į-Ni(OH) 2 [15] .…”

Homogeneous precipitation of layered Ni(II)–Cr(III) double hydroxides

“…The subsequent evolution of the coprecipitated hydroxides to form the final solid depends strongly on the reactivity of the involved metal ions; e.g., for labile ions, such as Cu 2+ and Zn 2+ , double basic carbonates form readily [38]. Thus, owing to the higher lability of Al 3+ than of Cr 3+ (Table 2), less stringent aging conditions are required for the preparation of Al(III)-containing LDHs via the urea method [9][10][11][12]. It should be recognized here that homogeneous nucleation of Zn(II)-Cr(III) LDHs takes place under the conditions provided by slow pH-titration experiments [40].…”

“…Typically, LDHs are synthesized following with slight modifications the recipe advanced by Miyata and Okada [4], i.e., coprecipitation followed by aging at moderate temperatures; the length of the aging stage depends on the degree of crystallinity that is pursued [5] and can be shortened by microwave dielectric heating [6][7][8]. Recently, LDH particles have also been prepared via the urea method [9][10][11][12], in which the rate of homogeneous alkalization is determined by the rate of urea hydrolysis [13], 3 . Contrasting with the abundant literature referring to the synthesis and properties of many different M(II)-M(III) LDHs, the information on Ni(II)-Cr(III) LDHs, which have been envisaged as potential electrode materials for alkaline secondary cells [14], is indeed scarce.…”

Enhanced electrochemical performance of high-density Al-substituted α-nickel hydroxide by a novel anion exchange method using NaCl solution

“…In order to overcome its intrinsic drawbacks, numerous efforts have been carried out by doping additional metal ions (e.g. Al [7e10], Co [11,12], Fe [13], Mn [14,15], or Zn [16,17]) in the lattice of nickel hydroxide. Among these metals, aluminum is considered the most effective element due to its high stability of the trivalent state and cheapness.…”