氧化铝模板的制备工艺研究

Study on Preparation of Aluminum Oxide Template

锡的氧化物作为锂离子电池负极材料是近来人们研究的热点之一，因为它的理论容量是石墨的2倍以上。然而，较大的首次容量损失是该材料的致命弱点。研究表明，纳米纤维结构的电极材料对解决该问题起到很大的作用。多孔氧化铝膜具有制备简单，控制纳米孔洞尺寸方便等优点，利用多孔氧化铝膜作为载体采用溶胶-凝股-模板法制备SnO2纳米纤维，对解决锂离子电池首次可逆损失以及今后研究以锡基纳米纤维作为锂离子电池负电池材料的电化学性能有很大的意义。为了找寻在草酸电解液中制备氧化铝模板的最佳工艺，针对各种工艺参数（如电流密度、氧化时间、电解液浓度等）对氧化铝膜形成的影响进行了研究，确定最佳工艺为：电流密度1．25A／dm^2，氧化时间1～2h，草酸电解液浓度为0．3～0．5mol／L，并对氧化锡纳米纤维结构进行了表征。

Li-ion battery anodes derived from oxides of tin that they can store over twice as much as graphite. However, large volume changes occur when Li is inserted and removed from these Sn-based materials, and this causes intemal damage to the electrode, resulting in loss of capacity and recharge ability. Prior work has shown that electrodes composed of smaller particles and crystallites show better cyclical ability. Aluminum anodic oxidation is a typical self-organization technique used to fabricate highly ordered array structures at a nanometer scale. SnO2 nanofiber is prepared using porous aluminum oxide template. The effects of the parameters of electrolyte density, anodic current and electrolytic solution concentration on preparation of template are studied in order to obtain the optimum process for preparing aluminum oxide template in oxalic acid electrolytic solution. The Al plate is electrochemically polished with 1 ： 4 mixture of perchloric acid and ethanol, the polished Al is anodized at 1.25 A/dm^2 in 0.3 ～ 0.5mol/L oxalic acid at 10℃ for 1 ～2h. The characterization of SnO2 nanofiber is shown.