高能球磨法制备新型电解电容器阳极材料低价铌氧化物工艺研究

Study of High Energy Ball Milling for Preparation of Niobium Suboxide Anode Material for New Electrolytic Capacitor

对在高能球磨中用Nb还原Nb2O5制备新型电解电容器阳极材料低价铌氧化物工艺进行了研究。研究对比了两种不同工艺方案:A,高能球磨混料-酸洗除杂-真空焙烧;B,高能球磨混料-真空焙烧-酸洗除杂。采用ICP、SEM分析检测方法对产物的杂质含量、微观形貌进行了分析研究。按与钽电解电容器相似的工艺将低价铌氧化物粉末制成了阳极,并采用电解电容器阳极测试方法对其电性能进行了研究。结果表明:A方案制备的产物比B方案的杂质含量低、漏电流小、比容低、损耗小,B方案产物比容可达107 000μF.V.g-1,两种方案制备的产物均有明显片式化现象、粒度细,但球磨过程中引入的杂质均难以在后续的洗涤过程中彻底除去,导致阳极漏电流较大。

Study is made of the preparation of niobium suboxide by Nb reduction of Nb2O5 through high energy ball milling. The following two different processes were studied and compared： A. high energy ball mill mixing - acid pickling for impurity removal - vacuum masting; B. high energy ball mill mixing- vacuum, roasting- acid pickling for impurity removal. Analysis is made by ICP and SEM of the impurity content and microscopic morpholcgy of the product. Anode is prepared from niobium suboxide and its electrical property is tested with processes similar to those for tantalum electrolytic capacitor. The resuls show that product prepared by Alternative A is characterized by lower impurity content, less leakage current, lower specific capacity and loss than that by Alternative B, which has specific capacity up to 107 000μF·V·g^-1; the particle size of product by high energy ball milling is fine, and inclined to slice. The entrapped impurity during ball milling is hard to be thoroughly removed in the subsequent washing step, resulting in large leakage current of the anode.