Low temperature route to nanocrystalline LiMn2O4 spinel

Novel graphene oxide/manganese oxide nanocomposites

“…In this case, Mn 2+ ions should oxidize and transform into four-valent manganese oxides. 35 We were able to demonstrate this experimentally by annealing the precursor in a two-step process consisting of: (1) vacuum annealing at 350 C, followed by (2) air annealing at 700 C. As shown in Fig. 6a, such two-step annealing preserves the spherical morphology of the nanocomposite.…”

“…for the metal ions to form citrate complexes. 34,35 Mn 2+ ions dissolved in distillate water are hydrolyzed and form MnOH + . Along with evaporation of water solvent at 150 C, the colloidal suspension of manganese citrate and subsequently a gel is formed.…”

Formation of hierarchical LiMn 2 O 4 dual-porous nanostructures by pyrolysis of gel precursor

“…During the thermal decomposition, there was a large quantity of heat releasing. The released heat firstly promoted the formation of Mn 3 O 4 [14], accompanying with the exothermic peak at 260°C. The pyrolysis of the remaining organic parts released heat to promote the formation of the LiMn 2 O 4 phase corresponding to the exothermic peak centred at 302°C.…”

“…All reagents were commercial compounds and of analytical purity grade. A typical procedure for preparation was similar to those described previously [14]: a 1:2 (mol) stoichiometric proportion of lithium acetate (Li(CH 3 COO) 2 ·2H 2 O) and manganese acetate (Mn(CH 3 COO) 2 ·4H 2 O) were dissolved in a minimum volume of ethanol. Then, an aqueous solution of citric acid (1.5 g) was dropwise added as a chelating and combusting agent into the above ethanol solution.…”