【作者】 王雪；

【导师】 谷臣清；

【作者基本信息】 西安理工大学 ， 材料学， 2007， 硕士

【摘要】 本文结合复合镍电极材料的制备与改性,研究了复合镍电极活性物质纳米Ni（OH）₂粉体的制备及氧化物类Ni电极活性材料ZnO粉体与纳米Ni（OH）₂粉体的化学镀镍工艺技术,以及化学镀镍对电极制备工艺性能及电极电学特性的影响。在采用正交试验筛选出ZnO化学镀镍处理基本工艺基础上,结合刚性开孔孔隙复合Ni电极材料的制备,对开孔孔隙的形成及高密度ZnO/Ni复合基体的获取工艺技术进行了研究,实验结果表明,通过对ZnO粉末进行预先化学镀镍处理,可显著提高其与制备复合镍电极用的金属镍粉末之间的烧结工艺性能,有利于通过采用粉末冶金技术,烧结制备出具备高致密性基体的刚性开孔孔隙复合镍电极材料。再借助向原材料混合粉末中添加部分纳米镍粉末,还可进一步提高ZnO的均匀弥散分布特性,有利于电极性能的改善;另外,发现ZnO粉末颗粒的表面状态对其乃至经化学镀镍处理后再与金属镍的烧结行为具有强烈的影响作用,对ZnO粉末进行400℃/ 2h预煅烧处理,可以提高ZnO粉末的表面活性,促进其烧结致密化进程。同时,实验结果还表明,以石蜡作造孔剂,所制备的开孔孔隙复合镍电极材料的孔隙较小,孔隙率较低;以食盐作造孔剂,其孔径与孔隙率较以石蜡作造孔剂均有显著增大与提高。但两种造孔剂的使用,均需合理控制在粉末冶金烧结过程中的脱出工艺环节,方能获取均匀分布的开孔孔隙。采用化学沉淀法制备的另一类复合镍电极用的活性物质-纳米Ni（OH）₂粉体材料,经XRD分析,结果表明氢氧化镍处于非晶状态;经TEM分析,其颗粒大部分为类球形,分散性良好,粉体平均粒径大约为20nm。化学沉淀法制备的初始态氢氧化镍粉末经270℃处理发生晶化,得到大小不等的多边形单晶体,单晶体尺寸介于1～3μm。差热分析的晶化峰值温度约为240℃。对非晶态纳米氢氧化镍粉体进行化学镀镍处理,获得了细小球状的镍包非晶态的氢氧化镍颗粒,颗粒粒径亦大约介于1～3μm。经对分别采用化学镀镍包覆纳米非晶态氢氧化镍粉末与未施镀的非晶态、晶态氢氧化镍粉末所制备的柔性复合镍电极进行放电特性实验,结果表明,采用镍包覆纳米非晶态氢氧化镍粉末所制备的复合镍电极的放电容量明显高于后两者。更多还原

【Abstract】 This paper unifing the preparation and modification of compound nickel electrode material, studied the preparation of compound nickel electrode active material nanometer Ni （OH）₂ powder and the technology of electroless nickel plating on oxides nickel the electrode active material ZnO and nanometer Ni （OH）₂ powder, as well as the electroless nickel plating influences on electrode preparation characteristics and electrode electricity characteristic.Through the orthogonal test screening the electroless nickel plating on ZnO processing craft foundation, unifing the preparation of inflexibility open pore compound Ni electrode material ,researched the technology of the high density ZnO/Ni compound and the open pore’s formating , the result indicated, through carring electroless nickel plating on ZnO powder which can remarkably enhance sinter characteristic between nickel powder and ZnO. It was also advantageous to preparing inflexibility open pore compound Ni electrode material with high compactability. Supporting to mix powder the partial nanometer nickel powder to the raw material ,may further enhance disseminate distribution characteristic of ZnO , but also was advantageous to improve the electrode performance; Moreover, discovered the ZnO powder’s surface condition can influence its behavior in sintering even after electroless nickel plating . Pre-scorifing on 400℃/2h to the ZnO powder , may enhance both its surface activity and its compact advancement .At the same time, the result also indicated that, taking paraffin wax as agent to make pore, can get nickel electrode material smaller pore and lower porosity .Taking salt as agent to make pore, can get remarkably increasing pore and enhancemental porosity. But when two kinds of agent being use, we need to control leaving of sinter process in the powder metallurgy , so as to gain the even distribute open pore .Using another kind of compound nickes electrode active material nanometer Ni（OH）₂ which through chemistry precipitation method got, after the XRD analysis, finally indicated the Ni（OH）₂ to be amorphous, the TEM analysis indicated, its pellet was sphere, and with high dispersivity and average grain diameter of the powder probably is 20nm. Chemistry precipitation method preparation initial condition nickelous hydroxide powder was be crystallization after 270℃processing ,obtains the size different polygon crystals whose size tobe situated between 1 3μm. The DTA crystallization peak value temperature was 240℃. Electroless nickel plating on it , obtained the tiny spherical Ni/Ni（OH）2 ,the particle size probably also was between 1 3μm .Testing the discharge of flexible compound nickel electrode ,indicated that compound nickel electrode discharge capacity using the Ni（OH）₂ which took electroless nickel plating before was higher than which using ordinary Ni（OH）₂ .更多还原