【作者】 蒋巍；

【导师】 梁广川；

【作者基本信息】 河北工业大学 ， 材料物理与化学， 2005， 硕士

【摘要】 本文针对锌电极的枝晶、形变、自腐蚀、钝化等问题,从电极材料的物理性能,以及电极和电解液的添加剂入手,采用不同的方法制备了锌电极并且对其进行了优化。探讨了锌粉的物理性能对锌电极的影响。通过电沉积实验发现,电流密度由小到大的情况下电沉积锌粉的颗粒逐渐变小;随着碱液浓度的增加锌粉的沉积形态由一维尺寸向三维尺寸发展。选取了电流密度为160mA/cm2;电解液为6M的KOH溶入饱和氧化锌溶液的电沉积工艺参数,制备出树枝状高比表面积(0. 168m2·g^-1 )的活性锌粉。采用辊压法制备的薄膜锌电极放电比容量达到了588. 8mAh·g^-1 ,锌粉的利用率达到71. 3%。分别用化学共沉淀法和球磨法合成了不同形态的锌酸钙,由这两种方法合成的锌酸钙同属单斜晶系,但在合成过程中它们的晶体生长取向不同。循环伏安曲线表明,由这两种方法合成的锌酸钙均具有较好的循环性能。在锌电极中加入适量的氢氧化钙,能有效的缓解锌电极放电产物在碱液中的溶解,提高锌电极的可充性,而又不对锌电极的阳极行为产生过大的阻化作用。添加CMC后,提高了锌电极的润湿性,形成了大量的离子传导通道,利于OH-离子的迁移,在一定程度上缓解了电极内部的“干涸”。在锌电极中添加Bi2O3、 PbO后,电极的放电性能得到了明显的改善,原因是Bi²⁺、Pb²⁺在锌离子还原之前被还原,作为锌沉积的基底使电极的导电性得到改善。在电解液中添加SDBS,其隔离了溶剂分子在电极表面的汇集,从而降低腐蚀速度。对于延长电极放电时间的作用,可以认为是有机表面活性分子在电极表面形成的膜占据了腐蚀反应进行的活性中心,提高了阳极反应的活化能。更多还原

【Abstract】 This paper aimed at problems such as dendrite, shape change, self-corrosion and passivation of zinc electrode, researched its physical performances, electrode additives and electrolytic additives, prepared zinc electrode by different methods and optimized its ingredient and content.First, it is discussed the influence of physical performance of zinc powders on zinc electrode. The method of electro deposition was used to prepare anode materials of battery. It can be found in electro deposit experimentation that along with the current density changing from low to high, grain size of zinc powders becomes smaller; along with concentration of KOH changing from low to high, the form of zinc powders grows into three-dimension from one-dimension. The active zinc powders with dendrite and high specific surface area (0.168m~2 g~-1) were prepared by controlling the technical parameters of electro deposition, namely the current density was 160mA/cm2, the alkaline electrolytic concentration was 6M that saturated with ZnO. Thin film zinc electrode was made by the method of rolling and pressing. When the battery composed of thin film zinc electrode discharged in constant current, the utilization ratio of the active zinc powders is 71.3%, and its specific capacity is as high as 588.8mAh g~-1.Calcium zincates were prepared by two methods, namely chemical co-precipitation method and ball-milling method. Although they all belong to monocline structure, but these calcium zincates form are different. This is due to different prior growth direction of crystal in the preparation process of calcium zincates. It can be concluded from CV curves that those calcium zincates had a good cyclic behavior and high discharge capacity. When adding suitable content of Ca(OH)2 into zinc electrode, it can be obtained from experiment that zincates solubility is reduced, recharging ability of zinc electrode has improved, and the adding of Ca(OH)2 won’t cause significant negative effect on anodic process.CMC serves as additive that can improve wet ability of zinc electrode and form a great dealchannels for ion conduction. The channels are good for OH" transfer and can decrease the "dry" inside electrode. Bi2+, Pb2+ were prior deoxidised before zinc ion. They serve as floor that can improve conductivity. As electrolytic additive, SDBS can stop solvent from congregating on the surface of zinc electrode to decrease anode corrosion. Discharge time of battery can be prolonging by SDBS. The mechanism can be explained in this way that organic surface-active molecules film on the surface of zinc electrode. The film takes up active center of corrosion reaction and improves activation energy of anode reaction.更多还原