纳米SnOx的水热合成及其储锂电化学性能

采用水热法在不同碱性条件下制备了不同形貌结构的SnO₂和SnO纳米材料，研究了两类锡基氧化物作为锂离子电池负极材料的储锂性能. 结果表明: SnCl₂·2H₂O直接水热水解或在碱性较弱时生成SnO₂，当碱性较强(pH>13)时则生成纳米SnO; 与SnO₂相比，SnO因其特殊的交叉网状花簇结构，表现出较高的首次充电、放电容量(1 059、1 590 mAh/g，库伦效率66.6%)、循环稳定性(循环500次，可逆容量达315 mAh/g)和倍率稳定性(在2.0 A/g下的可逆容量达到548 mAh/g). 碱性越强，SnO₂的循环稳定性和倍率稳定性越好，这归因于碱性越强生成的SnO₂颗粒越小，增大了电解液与电极材料的接触面积，缩短了Li+的传输距离，提高了循环稳定性和倍率稳定性. 研究结果为寻找长寿命、高容量负极材料的应用提供了参考.

Hydrothermal Synthesis of Nano-SnOx 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.