表面包覆CaSn（OH）6的锌酸钙的制备及其性质

采用化学沉积法在四边形锌酸钙表面包覆一层金属锡化合物.利用X射线衍射、扫描电子显微镜、电化学阻抗谱、Tafel曲线以及充放电循环(用做锌镍电池的负极材料)等方法,对包覆前后的锌酸钙样品进行表征.结果表明:包覆物化学组成为CaSn(OH)6,该包覆物在锌酸钙的表面分布均匀,沉积较为致密:包覆后的锌酸钙材料具有更好的耐腐蚀性能,且其电化学循环性能良好,经过135次循环后,电池放电容量仍保持设计容量的65.5%.     

掺Cr改性MnO2的制备及其电化学性能

采用低温固相氧化还原反应法制备出掺Cr的纳米MnO2.通过X射线衍射仪对其结构进行表征,结果表明:所得样品为α-MnO2和γ-MnO2的混合晶相,以纳米MnO2作为超级电容器的电极材料的单电极活性物质测得其比电容为95 F/g,掺入Cr的电极材料其比电容最大可达到163 F/g.循环伏安和恒流充放电测试结果表明,化学掺杂的配比对MnO2电化学性能的影响较大.当Mn与Cr的摩尔比为100:1时,材料具有较好的放电性能,其放电容量可提高70%.表明化学掺杂Cr有利于提高MnO2电极的电化学性能.     

Cl-和Zn2 阴阳离子复合掺杂α-氢氧化镍的结构与电化学性能

采用化学共沉淀法,制备出Cl-和Zn2 阴阳离子复合掺杂α-Ni(OH)2粉体.样品材料利用XRD、EDS、SEM、IR、DSC-TG和粒度测试仪进行结构形态及物理特性表征分析.同时以其为活性物质合成镍正极材料并组装MH-Ni电池,测试其充放电、循环可逆特性和交流阻抗等电化学性能.实验结果表明,在掺杂物质摩尔比为Cl-:Zn2 =1:3时,Cl-和Zn2 复合掺杂α-Ni(OH)2为层状结构,结晶水含量较高,热分解温度低.其MH-Ni电池在以80 mA/g恒流充电5 h,40 mA/g恒流放电至终止电压为1.0 V的充放电制度下,电化学极化阻抗较小,放电比容量为354.08 mAh/g,放电平台平稳、中值电压高达1.313 V,且经过多次充放电循环后,其电极活性物质仍然保持α-Ni(OH)2状态,电极过程结构稳定,循环可逆性较好,具有较高的电化学活性.     

锂离子电池微孔Sn-Co-C负极的制备及其性能

采用模板-电沉积法制备锂离子电池Sn-Co-C微孔负极。首先,采用聚合法制备PS球乳液。然后,再以柠檬酸、EDTA为络合剂,CoCl2、SnCl4为主盐,添加甲酸和PS球乳液的电解液中,电沉积制备Sn-Co-C微孔复合电极材料。随后采用EDS、XRD和SEM分析其元素成分、晶体结构和表面形貌。最后采用恒流充放电和交流阻抗测试其电化学性能。结果表明,电极表面的微孔可以缓解锂电池充放电过程中产生的体积变化所导致的活性物质脱落,提高循环性能和寿命。Sn-Co-C负极组成的电池首次充放电比容量分别为705.4和1105 mA.h.g-1,循环126次后充放电比容量分别为393.3和403.2 mA.h.g-1。     

Y(Ⅲ)/Mg(Ⅱ)复合掺杂非晶态氢氧化镍材料的电化学性能

采用微乳液化学共沉淀法制备出稀土Y(Ⅲ)与Mg(Ⅱ)复合掺杂非晶态氢氧化镍粉体材料。应用XRD、SAED、SEM及Raman测试样品材料的表观形貌及微结构特征,同时研究样品材料电极的电化学性能。结果表明:复合掺杂Y(Ⅲ)/Mg(Ⅱ)的非晶态氢氧化镍粉体微结构缺陷较多,无序性增强,呈不规则的类球形;材料粉体作为MH-Ni电池正极活性物质,在充放电过程中电化学阻抗较小,在以0.2C充放电,终止电压为1.0V的制度下,其放电比容量高达到364.75mAh·g-1,同时放电中值电压较高并稳定于1.276V,1C下其放电比容量可达348.82mAh·g-1,充放电循环50次容量保持率为91.87%,显示出良好的较大倍率放电性能和循环可逆性能。     

锌电级的一种新的成型工艺及其电化学性能研究

探讨了用铸造法得的多孔锌电极的电化学性能。指出：由于采用铸造法可提高电极的孔隙率、强度、增大电极的孔径、降低电极的内阻,从而使得电极的活性物质利用率,电极的实际比容量得以极大的提高。     

镀镍石墨粉的电化学性质

利用化学镀方法在石墨粉表面镀覆了一层均匀、完整的金属镍,研究了镀镍石墨粉电极及镀镍石墨粉作为ＭＨ／Ｎｉ电池镍电极导电剂时的电化学性质。实验表明,石墨粉表面镀覆金属镍可增另其电化学活性;用镀镍石墨粉作为电极导电剂时,可以改善镍电极的导电性能,降低电池内阻,提高正极活性物质的利用率,且电池的循环稳定性好,以１Ｃ倍率充放电循环１２０就衰减。     

冷喷涂制备纯硅负极结合特性对电极性能的影响

目的 提高冷喷涂制备锂离子电池硅(Si)基负极的电化学性能,探究冷喷涂制备硅基负极结合特性对电极性能的影响。方法 通过涂覆和冷喷涂制备硅基负极,利用剥离强度试验测试活性材料与集流体的结合强度。通过扫描电镜表征充放电前后电极表面及断面形貌,分析2种电极的结构稳定性。通过观察单颗粒子沉积形貌,研究硅颗粒的沉积特性。采用恒流充放电、循环伏安法、交流阻抗法分别研究电极的循环性能和动力学特性。结果 在相同剥离条件下,Si–喷涂样品结合强度高,且剥离现象出现较晚,Si–喷涂样品的平均载荷为2.04 N,大于Si–涂覆样品的平均载荷(1.51 N)。Si–涂覆电极材料与集流体的贴合度较差,铜箔与涂层以及涂层材料内部均存在大量的孔隙结构,Si–喷涂电极活性材料均匀沉积于铜箔表面簇状的缝隙中,涂层较薄,未能覆盖簇状凸起。硅颗粒无法连续沉积形成较厚的涂层,仅以嵌入的方式沉积于铜箔表面。Si–涂覆电极循环200次后,容量仅剩51 mAh/g,而Si–喷涂电极循环200次后,容量高达240 mAh/g。Si–喷涂电极的Rct比Si–涂覆小,说明Si–喷涂电极的嵌入式结构利于电荷的转移。Si–涂覆电极的锂离子扩...     

Al含量对Al取代氢氧化镍振实密度及电化学性能的影响

采用化学共沉淀法制备了Al~(3+)/Ni~(2+)摩尔分数分别为0%,5%,10%,15%和20%的Al取代Ni(OH)2样品。振实密度测试发现当Al含量低于10%时,随着Al含量的增加样品的振实密度急剧增大;当Al含量为10%时,样品具有最大的振实密度;继续增加Al含量,样品的振实密度开始降低。X射线衍射分析发现,当Al含量低于5%时,样品的晶型为β相;当Al含量在5%~10%时,样品的晶型为α/β混合相;当Al含量高于10%时,样品的晶型为α相。循环伏安(CV)、电化学交流阻抗(EIS)和充放电测试研究表明:掺Al样品比未掺Al样品具有更高的电化学活性。其中Al含量为15%的样品具有最好的电化学性能,在100 m A/g恒电流充放电下的稳定质量比容量和体积比容量分别高达324 m Ah/g和516m Ah/cm~3,并且具有优异的循环性能。     

B掺杂对NiO/Ni(OH)_2电极材料电容性能的影响

通过化学镀再电化学氧化的方法在铜片表面制备出带有微米微坑和微米微球的均一NiO/Ni(OH)_2和B掺杂的NiO/Ni(OH)_2(B)2种电极材料,采用扫描电镜/能谱(SEM/EDS)、X射线衍射(XRD)仪、X射线光电子能谱(XPS)和电化学技术对所制备的2种电极材料进行表征和电化学性能测试。SEM、XRD和XPS的测试结果表明,所制备的2种电极材料由Ni、NiO和Ni(OH)_2组成,并且NiO/Ni(OH)_2(B)中B的掺杂量可达14.6%(质量分数)。循环伏安测量和恒电流充放电试验表明,2种电极材料均具有较高的电化学活性和可逆性;在1A/g的充放电电流密度下,NiO/Ni(OH)_2和NiO/Ni(OH)_2(B)电极材料经历10 000次充放电循环后分别给出了1380和1930 F/g的比电容,显示出较高的比电容特性和良好的电化学稳定性;电化学阻抗谱表明,NiO/Ni(OH)_2(B)电极材料较NiO/Ni(OH)_2电化学反应电阻降低了约2个数量级;Ragone曲线揭示了所制备的2种电极材料具有较高的功率密度和较低的能量密度。B的掺杂使得NiO/Ni(OH)_2(B)电极材料表面氧化物含量增大并且形成微米微球形貌,增大了电极表面积以及与电解液的接触和润湿作用,降低了电极材料表面能带带隙能,从而导致电化学反应电阻较小和电导率提高,这是其显示优异赝电容性能的主要原因。     

Effects of pH value of reaction solution on structure and electrochemical performance of calcium-containing active material of secondary zinc electrodes

The calcium-containing active material of secondary alkaline zinc electrodes was prepared by a chemical coprecipitation method and characterized by scanning electron microscopy(SEM) and X-ray diffractometry(XRD).Their electrochemical performance was tested by the Galvanstatic charge-discharge method. The experimental results show that the sample synthesized at pH: 11. 15 has a typical calcium zincate crystal. The zinc electrode using this sample as active material shows higher discharge capacity, more negative discharge plateau potential and longer cycle lifetime.     

添加剂对锌电极性能的影响(英文)

为了改善镍锌电池的性能,同时研究电极中添加剂对锌电极性能的影响,选用正交设计对影响锌电极的4个因素(乙炔黑、Bi2O3、PbO、包覆La(OH)3的Ca[Zn(OH)3]2·2H2O)选择3个水平进行测试。对没有任何添加剂的氧化锌在20%KOH电解液中进行充放电循环实验,研究添加剂的作用。为了更好地解释锌电极放电容量衰减的原因,对正交实验的最差样品和最优样品放电产物所含的Zn和Ca的比例进行分析。通过表征,得出了在该实验条件下的电极添加剂的最优配比方案为:在5g样品中,乙炔黑0.02g,Bi2O3 0.5g,PbO 0.3 g,包覆La(OH)3的Ca[Zn(OH)3]2·2H2O)0.2g。     

全光亮碱性锌酸盐镀锌工艺研究

在碱性锌酸盐镀锌基础液中加入自制光亮剂XY-03A,研究成功了一种全光亮碱性锌酸盐镀锌工艺,确定了电镀工艺规范,采用霍尔槽试验探讨了主要成分对镀层质量的影响,检测了镀液和镀层性能,结果表明：所形成的锌镀层光亮度高,镀层结晶细致,与基体结合力好;镀液的分散能力、复盖能力、电流效率和镀层耐蚀性优于DE型镀锌工艺,具有较高的应用价值.     

The effects of polyethylene glycol (PEG) as an electrolyte additive on the corrosion behavior and electrochemical performances of pure aluminum in an alkaline zincate solution

The effects of zinc oxide and/or polyethylene glycol (PEG) as electrolyte additives on the corrosion and electrochemical performances of pure aluminum in 4.0 M KOH solutions were investigated by means of hydrogen collection, polarization curve, galvanostatic discharge, scanning electron microscopy (SEM), and energy dispersive analysis of X‐ray (EDAX). The addition of ZnO markedly inhibited the corrosion of aluminum in 4.0 M KOH solutions, resulting from the deposition of zinc with high hydrogen evolution overpotential in aluminum surfaces. The introduction of PEG in the alkaline zincate solution obviously improved the deposition of zinc by increase in the overpotential of zinc deposition, thus the corrosion rate of aluminum in the alkaline zincate solutions with PEG was further decreased. The enhancement effect of PEG on the inhibition of zinc oxide first increased and then decreased with increasing the content of PEG in the electrolyte. The electrolyte system with 0.2 M ZnO and 2.0 mM PEG presented the highest inhibition efficiency (98.8%) for the corrosion of aluminum. The results of galvanostatic discharge indicated that the aluminum anode shows excellent discharge performances in the 4.0 M KOH solution with 0.2 M ZnO and 2.0 mM PEG.     

纳米氧化锌对镍氢电池电化学性能的影响

采用均匀沉淀法制备纳米氧化锌,将其作为添加剂掺杂制备MH/Ni电池正极,研究正极中添加不同质量分数的纳米ZnO对电极电化学性能的影响,初步探讨纳米氧化锌在电极内部的反应机制。结果表明,掺杂后氢氧化镍电极的导电性提高,电化学活性增强,有效地提高了活性物质的利用率,改善了电极反应的传质和传荷条件,使电极中电活性粒子具有合理的分布,因而显示出良好的电化学性能。经过比较,添加质量分数为4%的纳米ZnO电化学性能最佳,在60周和80周时放电容量仍有282和272mAh·g-1,而且放电平台较高。     

重稀土元素对氢氧化镍电极高温性能的影响

研究了在覆钴球镍中低量添加重稀土元素对镍电极性能的影响。结果表明,60℃时添加1%(原子分数)重稀土的镍电极的1C充放电效率比无添加剂的镍电极有所提高;重稀土氧化物的添加对镍电极的常温高倍率放电性能有一定的负面影响;在常温时,重稀土氧化物的加入增大镍电极氧化-还原反应的电位差,从而增大电极反应的不可逆性,其中添加氧化铥与氧化镥的电极最为明显;在60℃时,添加重稀土氧化物的镍电极的氧化峰与析氧峰区别明显,且镍电极的氧化峰电位与析氧电位普遍负移,还原峰电位普遍正移,显著提高镍电极在高温下的析氧过电位以及可逆性。     

柿竹园铅锌尾矿湿化学法合成硅酸钙粉末

将柿竹园铅锌矿破碎球磨,进行煅烧、除硫,经浓盐酸酸洗、过滤,实现了有价元素与其他元素的分离,通过控制不同的pH值,分别得到铁和铅锌的氢氧化物,再往滤液中加入NH4HCO3,钙以CaCO3的形式沉淀出来,将所得的碳酸钙经硝酸溶解后,加入适量的硅酸钠,并用聚乙二醇作为分散剂,制得硅酸钙粉体.并对制各的溶液和滤渣进行了表征,研究了焙烧物料的数量和金属的离子价态对产物纯度和回收率的影响.本试验通过控制适宜的工艺条件,使铁和钙的浸出率分别达到83.2%和67.7%,工艺简便,成本较低,实现了矿产资源的综合利用.     

Effects of additives on zinc electrodeposition from alkaline zincate solution

The effects of additives on the surface and cross-sectional morphologies of zinc deposits on iron substrate from alkaline zincate solution were characterized by scanning electron microscope (SEM). The cathodic reaction mechanisms under various concentrations of additives were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. It is found that with increasing the additive A content in the bath solution, the nucleation overpotential (NOP) value is obviously increased and the inhibition effect is strengthened. This may be mainly due to the adsorption of additive A on the cathodic electrode surface, which can cover the active sites and block the discharge reduction. The results of EIS analysis indicate that the rate-determining step of zinc electrodeposition process is changed from mixed control step into electrochemical reduction step in the presence of additive A. However, any quantity of additive B has little effect on the NOP value and the inhibition effect is not obvious. Furthermore, addition of additive A and additive B at the same time displays the strongest inhibition effect and shows a strong synergism because of their co-adsorption on the cathodic electrode surface.     

锌酸盐对Zn在KOH溶液中腐蚀及电化学行为的影响

用电化学方法研究了锌酸盐对Zn在KOH溶液中腐蚀及电化学行为的影响,提出了K2Zn(OH)4在高浓度时对析氢反应的促进机制,并对观察到的实验现象进行了讨论     

Characterization of alkaline-earth oxide additions to the MnO2 cathode in an aqueous secondary battery

The effect of alkaline-earth oxide additions on aqueous rechargeable battery is investigated using microscopic and spectroscopic techniques. The alkaline-earth oxide additions such as magnesium oxide (MgO) and barium oxide (BaO) were physically mixed to the manganese dioxide (MnO₂) cathode of a cell comprising zinc as an anode and aqueous lithium hydroxide as the electrolyte. The results showed that such additions greatly improved the discharge capacity of the battery (from 145 to 195 for MgO and 265 mAh/g for BaO). Capacity fade with subsequent cycling is reduced only for MgO but not for BaO. With an aim to understand the role of these additives and its improvement in cell performance, we have used microscopy, spectroscopy, ion beam analysis and diffraction based techniques to study the process. Transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy analysis (EDS) results showed evidence of crystalline MnO₂ particles for MgO as additive, whereas, MnO₂ particles with diffused structure leading to mixture of phases is observed for BaO additives which is in agreement with X-ray diffraction (XRD) data. This work relates to improvement in the electrochemical behaviour of the Zn-MnO₂ battery while the MgO additive helps to reduce the formation of manganese and zinc such as hetaerolite that hinders the lithium intercalation.