Assembled hollow and core-shell SnO2 microspheres as anode materials for Li-ion batteries

SnO2 microspheres with controllable morphology were prepared via a hydrothermal-annealing method. The SnO2 morphology can be tuned by using AlOOH sol and γ-Al2O3 as additive. The hollow SnO2 microspheres with incomplete core-shell structure prepared with small amount of γ-Al2O3 presented the best cycling performance in Li-ion battery, exhibiting a specific capacity of 374.2 mAh g−1 up to 100 cycles. The superior performance can be mainly attributed to the formation of more and smaller SnO2 hollow microspheres and partial core-shell SnO2 microspheres resulting from the γ-Al2O3 condensation nucleus. The unique hollow and core-shell composite structure of SnO2 is capable of reducing the volume changes during Li insertion–extraction.

Graphical abstractA new synthesis method was developed to prepare SnO2 microspheres with controllable morphology through adding AlOOH sol and γ-Al2O3 as additives in a hydrothermal strategy for the first time. The prepared hollow and partial core-shell composite structure SnO2 microspheres exhibited the much improved cycling performance, compared to currently reported SnO2 anodes. The superior performance derived from the addition of γ-Al2O3 in systhesis was discussed in a correlation of the prepared unique hollow microspheres with incomplete core-shell structure observed in the SnO2 microspheres.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Morphology-controlled synthesis of SnO2 microspheres were successfully achieved. ► An annealing process was introduced for strengthening the crystal of samples. ► The additive-effect on morphology of SnO2 microspheres was proposed. ► The core-shell SnO2 hollow microspheres exhibited the best cycling performance