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Structure and insertion properties of disordered and ordered LiNi0.5Mn1.5O4 spinels prepared by wet chemistry

“…The choice of these wet-chemical techniques has been guided by the remarks of Zhong et al [4]. The sol-gel and combustion synthesis occurred from metal acetates via inorganic polymerization reactions in solution according to methods reported in our previous works [28,29]. Compared with the conventional solid-state reaction, it is believed that these techniques offer many advantages such as lower temperature processing and better control of material morphology.…”

“…The procedure for the sol-gel synthesis has been detailed elsewhere [28]. O acetate dissolved in distilled water and added to a continuously stirred aqueous solution, and then evaporated at 80°C until a transparent gel was obtained.…”

Preparation of an Li0.7Ni0.8Co0.2O2 Electrode Material From a New Li–Co–Ni Mixed‐Citrate Precursor

“…to produce materials with a high chemical homogeneity and small particle size. [21][22][23][24][25][26][27][28][29][30] This method involves the precipitation of citrate salts at controlled pH and concentration ratio of the involved ions, followed by their thermal decomposition. The Pechini process [26] for the synthesis of mixed oxides is one of the different reported pathways in which polyhydroxy alcohols are used to produce the esterification of complex mixtures of citrates to give a polymeric resin, which is decomposed above 400°C.…”

“…[21,[23][24][25][26] However, the formation of a dense and rigid resin intermediate of citric acid and ethylene glycol, which leads to crystallite agglomeration during pyrolysis, has been found to be a critical problem of this approach. [25] A modified Pechini method has been reported recently by Julien et al, [30] in which a gel precursor is prepared by addition of citric acid to a mixture of the metal acetates followed by heating at 800°C to obtain the micro-sized LiNi 0.6 Co 0.4 O 2 phase. Alternative routes [27][28][29][30] are based on the higher solubility of the citrate salts in ethanol vs. water, as reported by Zhecheva and coworkers [29] for the preparation of LiCoO 2 powders with small particle size.…”

“…[25] A modified Pechini method has been reported recently by Julien et al, [30] in which a gel precursor is prepared by addition of citric acid to a mixture of the metal acetates followed by heating at 800°C to obtain the micro-sized LiNi 0.6 Co 0.4 O 2 phase. Alternative routes [27][28][29][30] are based on the higher solubility of the citrate salts in ethanol vs. water, as reported by Zhecheva and coworkers [29] for the preparation of LiCoO 2 powders with small particle size. These authors showed that the chelating ability of citric acid, and therefore its ability to form complexes with metal ions, is highly dependent on the ions' concentration.…”