锌镍电池及其正极材料研究

【作者】 侯立松；

【导师】 徐徽；

【作者基本信息】 中南大学 ， 冶金物理化学， 2005， 硕士

【摘要】 本论文综述了国内外锌镍电池的研究和发展现状,指出了锌镍电池研究中目前存在的问题,采用化学分析、X-射线衍射分析（XRD）、扫描电镜（SEM）、充放电性能测试等多种化学与电化学研究手段,对锌镍电池及其正极材料氢氧化镍的制备、结构及性能进行了探讨。首次采用半连续的化学沉淀-晶种长大法制备锌镍电池正极材料Ni（OH）₂,重点考察了沉淀反应次数对Ni（OH）₂物理及化学性能的影响,通过组装Zn/Ni模拟电池,对其电化学性能进行测试。最后,试制了锌镍一次电池,并对电池的性能进行了检测。 采用半连续的化学沉淀-晶种长大法制备出了堆积密度和结晶度较高、流动性较好的球形氢氧化镍,得到制备Ni（OH）₂的最佳工艺参数为:pH=11.0～12.0,反应温度为50～60℃,氨镍比=1.1,固液比在140～160g/L,反应时间为7～9h;此外,还分析了搅拌强度、加料方式、反应物浓度、陈化时间等因素对Ni（OH）₂性能的影响。通过XRD和SEM检测结果表明,所得Ni（OH）₂的晶型为β—Ni（OH）₂,颗粒呈球形和椭圆形状,晶胞结构完整,晶体结构有序,颗粒粒径粗大,粒径分布在5～15μm之间。 通过组装锌镍模拟电池,研究了不同充放电倍率下镍电极的充放电性能,以及掺杂Co、Ni、Zn、MnO₂等物质对Ni（OH）₂电极电化学性能的影响。结果表明:充放电倍率对活性物质的利用率、放电倍率有较大的影响:镍电极中添加Co、Ni、Zn等可以较大程度上提高活性物质的利用率、提高放电半电位、缩短活化次数,而添加MnO₂反而会降低活性物质的利用率和放电半电位。Ni（OH）₂粉末微电极循环伏安研究结果表明:随着扫描速度的增加,电流的峰值不断的增加,峰电位差基本上不变;经测试,Ni（OH）₂样品的循环寿命可达600次。 选用K₂S₂O₈为氧化剂,将Ni（OH）₂氧化成充电态电池正极材料NiOOH,采用碱锰电池的负极及生产工艺,制作成AAA型锌镍一次电池。电池开路电压1.75V左右,3.9Ω恒阻连续放电至1.2V,其放电时间是碱锰电池的3倍左右。更多还原

【Abstract】 The current conditions and existing problems in the research and development of zinc-nickel batteries were analyzed in this thesis. The crystal and chemical structure characteristics and electrochemical properties of Ni（OH）₂ were investigated in the use of chemical analysis methods, SEM, XRD and so on. The preparation and application of positive electrode material Ni（OH）₂ was extensively studied. The hemicontinuous chemical deposition-crystal seed growth method was adopted for the first time to prepare the positive electrode material Ni（OH）₂. The influence of deposition reaction times was studied. The Zn/ Ni emulation batteries were assembled and their electrochemical capabilities were tested as well. The Zn/Ni primary batteries were produced at last, and their dischargeable performances were detected.In this thesis, the spherical Ni（OH）₂ with high tap density, crystallinity degree and good flowability was prepared with hemicontinuous chemical deposition - crystal seed growth method. The optimal technological parameters are: pH=11.0, reaction temperature is 50℃, NH₃/Ni= 1.1, the solid material content was controlled in the range of 140¹60g/L, and the reaction time is 7 hours . In addition, the agitation strength, the concentration of the raw material, the aging time, the charging method of raw material and some other factors were also studied. The basic crystal structure of Ni（OH）₂ was found to be β-Ni（OH）₂ by using of advanced physical analysis of SEM and XRD. The particle crystal is in order, crystallinity degree is high, and the crystallite size is big. The size of particles distributes from 5 to 15 μm.The charge-discharge capabilities of the Electrodes doped with Co、 Ni、 Zn、 MnO₂ were studied by testing a Zn/Ni simulation battery. The results show that the effects of charge-discharge rate on the utilization of active material and average potential of electrode. Doping Co、 Ni、 Zn can increase the utilization of active material, enhance average potential and reduce the cycle times. But the utilization of active material and averagepotential are reduced after doping MJ1O2. Cycle Voltammetry （CV） of power microelectrodes of Ni（0H）2 showed that the higher the scanning rate in the range of 10⁵0mv/s, a higher current peak value, and cycle life of Ni（0H）2 power microelectrodes is 600 times.The Ni（OH）2 was oxidized to NiOOH when K2S2O8 was used as oxidizing agent. AAA type Zn/Ni primary batteries were made by using the alkaline manganese battery production line. The open circuit voltages of the batteries are about 1.75V. The permanent resistant （3.9Q） continuous discharge time of the Zn/Ni primary batteries is about 3 times of alkaline manganese batteries.更多还原