Sol-gel synthesis and leaching of potassium hollandites

The results of a physicochemical study of hollandite-type minerals synthesized by the citrate-nitrate sol-gel method in the K2O-M2O3-TiO2 systems (M = Ga, Fe, Cr) and subjected to leaching in a mixture of hydrogen peroxide and sulfuric acid are reported. The materials thus prepared are stable up to 400°C and decompose above this temperature. The experiments performed confirm a decrease in the potassium content of these triple oxides upon such chemical treatment by 26–36% of the initial level, which makes these oxides promising for use as electrode materials for lithium-ion batteries.