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A composite based on sodium germanate and reduced graphene oxide was obtained for the first time by precipitating the initial peroxogermanate on a graphene oxide followed by heat treatment in vacuum. According to powder X-ray diffraction, sodium germanate crystallizes during the heat treatment in vacuum at 500°C. Scanning transmission electron microscopy examination showed that sodium peroxogermanate nanoparticles form a thin film on the surface of graphene oxide flakes. The electrochemical characteristics of composites obtained with different heat treatment conditions were studied as the anodes of lithium ion batteries.

We report the first attempt to study the behavior of the [AlO4Al12(OH)25(H2O)11]6+ (Al13) Keggin cation (KC) in water–peroxide solutions. Addition of hydrogen peroxide into an aqueous solution containing the Al13 KC reduces pH due to the acidity of hydrogen peroxide. According to the 27Al NMR studies of water–peroxide solutions prepared just before the NMR experiment, with their pH adjusted to the initial value of 5.5 with aqueous NaOH, the Al13 KC concentration decreases immediately once hydrogen peroxide is added to the initial system. Addition of 18.2 wt % hydrogen peroxide to the initial 0.88 mM Al13 solution gives rise to a fourfold decline in Al13 polyoxo cation concentration to 0.22 mM. Then, the KC concentration in the test system remains unchanged for 1 week. Large hydrogen peroxide amounts (27.9 wt % or higher) added to the initial system almost completely degrade the KC. Sodium sulfate added to the initial water–peroxide solution of Al13 chloride where the hydrogen peroxide concentration is 5.5 wt % precipitates the earlier described Al13 sulfate [AlO4Al12(OH)25(H2O)11](SO4)3 · 16H2O, where the aluminum polyoxo cation does not contain coordinated hydrogen peroxide molecules, peroxo or hydroperoxo groups as shown by X-ray diffraction.

Using peroxostannate as a precursor, a composite material based on tin dioxide and carbon black was obtained, in which tin dioxide forms a coating on the surface of carbon black nanoparticles. The synthesized material was characterized by electron microscopy and X-ray powder diffraction analysis, and also the electrochemical characteristics of this material as an anode material for lithium-ion batteries were studied. The material demonstrates good stability and rate performance, which is indicative of the efficiency of the peroxide method for producing promising inexpensive anode materials based on tin dioxide and carbon black.

A tin dioxide–sodium stannate composite has been obtained by the thermal treatment of sodium peroxostannate nanoparticles at 500°C in air. X-ray powder diffraction study has revealed that the composite includes crystalline phases of cassiterite SnO2, sodium stannate Na2Sn2O5, and sodium hexahydroxostannate Na2Sn(OH)6. Scanning electron microscopy has shown that material morphology does not change considerably as compared with the initial tin peroxo compound. Electrochemical characteristics have been compared for the anodes of lithium-ion batteries based on tin dioxide–sodium stannate composite and anodes based on a material manufactured by the thermal treatment of graphene oxide–tin dioxide–sodium stannate composite at 500°C in air.