Study of calcium zincate synthesized by solid-phase synthesis method without strong alkali

Increasing the Electrolyte Capacity of Alkaline Zn–Air Fuel Cells by Scavenging Zincate with Ca(OH)2

“…This suggests that calcium zincate is barely formed through the hydrolysis of ZnO and Ca(OH) 2 in the presence of ample water, as the solubility of both ZnO and Ca(OH) 2 in water is low (1.6 and 1.73 g L À1 at 20 8C, respectively), [29] and at least an energy of 6.917 kJ mol À1 is needed to complete the conversion at room temperature. [19,20] It should be mentioned that calcium zincate can be produced by continuous stirring and aging of the mixture of Ca(OH) 2 , water, and ZnO at a high temperature [30] or by ball milling. [31,32] In the second experiment, both Ca(OH) 2 and ZnO were found to dissolve sparingly into the KOH solution upon stirring for 6 h, suggesting possible calcium zincate formation.…”

Preparation and electrochemical performance of nanosized Bi compounds-modified ZnO for Zn/Ni secondary cell

“…The oxidation reaction of the physically mixed ZnO occurs in terms of equation (2). Surface modification decreases the contact area between active material and the electrolyte, which leads to an inadequate contact between the active material and OH − ion at the reaction layer.…”

“…However, widespread commercialization of the Zn/Ni cell has been limited due to the serious problems such as Zn dendritic growth and shape change of the ZnO electrode. Up to now, most researches on this field have focused on additives to the ZnO electrode or the electrolyte, selection of stable separators and other techniques, for example, Bi 2 O 3 [1], calcium zincate [2,3], conductive-ceramic nanocomposite [4], tetra-alkyl ammonium hydroxides [5] and alkaline polymer hydrogel electrolyte [6] were once investigated in recent years. On the whole, electrode additive is the most important method to improve the electrochemical performance of ZnO [7][8][9].…”

Immobilization of Zn(II) in Portland cement pastes

“…For this purpose, the method of Wang et al [26] was used although it had some slight modifications. Solid reagents ZnO (from Guinama, USP reagent) and Ca(OH) 2 (from Panreac, quality reagent), in a 2/1 molar ratio, were added to a well-sealed reaction vessel containing distilled water and connected to a thermostatic bath (P-Selecta, Ultraterm model) at a controlled temperature of 75 ºC.…”

“…8 In order to detect the presence of CaZn 2 (OH) 6 ·2H 2 O, a previous thermogravimetric analysis was performed to the sample synthesized as reference [26] for Zn (II) containing pastes. Figure 3 shows their TG and DTG curves.…”