Hydrothermal Synthesis of Nano-SnO_x and Its Electrochemical Performance for Lithium-ions Storage

SnO₂ and SnO nanomaterials with different morphologies and structures were prepared with the hydrothermal method under different alkalinity conditions, and the lithium-ions storage performance of the two kinds of tin-based oxides as anode materials for lithium-ion batteries was studied. The results showed that SnO₂ was formed through direct hydrolyzing of SnCl₂·2H₂O or when the alkalinity of the solvent was low. Nano-SnO was formed when the alkalinity was high enough (pH>13). Compared with SnO₂, SnO had a special cross-network flower-cluster structure, which resulted in higher initial charge and discharge capacity (1 059 and 1 590 mAh/g, with an initial coulombic efficiency of 66.6%), cycle stability (the reversible capacity up to 315 mAh/g after 500 cycles) and rate stability (the reversible capacity up to 548 mAh/g at 2.0 A/g). The higher the alkalinity, the better the cycle stability and rate stability of the synthesized SnO₂, which is due to the smaller SnO₂ particles generated by the stronger alkaline, which increases the contact area between the electrolyte and electrode materials, shortening the transmission distance of Li⁺, improving cycle stability and rate stability. The results provide a reference for the application of anode materials with long life and high capacity.