电沉积制备La-Mg-Ni贮氢合金薄膜及其性能的研究

采用恒电流沉积方法在水溶液中沉积出LaMgNi4合金薄膜。利用循环伏安、模拟电池充放电循环、扫描电镜(SEM)以及X射线衍射(XRD)等方法研究了电沉积合金薄膜的电化学性能和表面形貌及结构。结果表明,该合金薄膜作为贮氢电极具有较好的电化学性能,其电化学活性高,活化性能好,首次充放电比容量达398mAh/g。     

Ti—Ni非晶合金贮氢薄膜制备及电化学性能研究

利用离子束溅射的方法（ＩＢＳ）制备了Ｔｉ－Ｎｉ非晶合金薄膜,采用ＸＲＤ、ＳＥＭ方法研究了薄膜试样充放电前后的结构和形貌变化,采用电化学方法研究了这种材料的电化学贮氢性能,试样Ｔｉ５０Ｎｉ５０最高电化学容量可达４５８ｍＡｈ／ｇ。引用Ｈａｒｒｉｓ模型估算了Ｔｉ－Ｎｉ非晶合金薄膜的理论电化学贮氢容量,并用以分析实验结果。     

热处理对LPC（NiCOAlMn）5.0贮氢合金电化学性能的影响

研究了673，1173，1373K热处理对贮氢合金活化性能，放电容量以及高倍率放电等电化学性能的影响。结果表明：1173，1373K热处理后，合金充放电循环稳定性及高倍率放电性能得到改善；其中1173K热处理合金的在0．4C充放电时最大放电容量与铸态合金相比没有下降，而循环稳定性及高倍率放电性能有明显的改善，具有优良的综合电化学性能。     

贮氢电池的充放电过程研究

研究了贮氢电池充放电过程与活化、温度以及充放电制度等多种因素之间的关系,探索了贮氢电池性能变化的内部原因。结果表明：通过对贮氢合金进行适当的表面处理,提高氢原子在贮氢合金中的扩散系数,降低贮氢合金裂纹扩展系数等可以提高贮氢电池的活化、低温、大电流、循环等充放电特性,从而提高贮氢电池的综合性能。这些结果对储氢材料及贮氢电池设计、工艺研究等提供了基础性资料及理论依据。     

镁基贮氢合金的研究及发展

贮氢材料的发展是氢能利用的关键技术，作为新型贮氢材料-镁基贮氢合金，由于其具有超高理论电化学容量的优势而受到全世界瞩目。本文阐述了镁基贮氢合金的电化学性能特点，介绍了镁基贮氢合金成分设计及制备工艺的国内外现状，指出了未来镁基贮氢合金应用研究的重点。     

银添加剂对贮氢合金电极性能的影响及机理

用恒电流充放电和脉冲放电方法研究了含银添加剂对富镧AB5型贮氢合金电极电化学性能的影响。结果表明Ag添加剂加快了氧的电化学复合速度，延长了贮氢合金的使用寿命。含银添加剂MH／Ni电池在-20℃和55℃下的1C放电容量、循环寿命和高倍率(5C，10C，15C，20C)脉冲放电性能均高于空白电池。对不同温度下的含银添加剂MH电极进行了电化学阻抗谱和循环伏安实验，分析认为MH电极在25℃与55℃下的高倍率放电性能受氢扩散控制，而在0℃下则受电极表面的电子转移控制。     

利用表面修饰提高AB5型贮氢电极性能

贮氢合金的表面性质对于它的电化学应用十分重要.AB5病型贮氢合金虽然具有活化性能好,容量在260mA·h/g～320mA·h/g是目前生产MH-Ni电池负极的主干材料.但是AB5,型贮氢合金在反复充放电过程中抗氧化和抗粉化的能力很差,导致放电容量的迅速降低.综述和比较了近年来对AB5,型贮氢合金表面处理的研究情况,分析了表面与电极性能的关系.     

氟化处理对La0.67Mg0.33Ni2.25Co0.75贮氢合金电化学性能的影响

采用扫描电镜、充放电测试、线性极化和电位阶跃等方法研究了氟化处理对La0.67Mg0.33Ni2.25Co0.75贮氢合金电化学性能的影响。结果表明,氟化处理提高了合金电极的循环稳定性,合金电极50次充放电循环后的容量保持率显著提高。同时,氟化处理也提高合金电极的交换电流密度,降低极化电阻,并且有利于氢在合金中的扩散,从而显著改善合金的高倍率放电性能 (HRD)     

电解液中添加Cu(OH)2对La2MgNi7.5Co1.5 贮氢合金电极电化学性能的影响

采用电子探针(EPMA)、X射线衍射(XRD)和电化学测试研究了在6 mol/L KOH电解液中添加Cu(OH)2对La2MgNi7.5Co1.5贮氢合金电极电化学性能的影响.结果表明,合金电极外表面上被镀上Cu膜,Cu膜的厚度和致密性随充放电循环次数的增加而增加,合金电极表面形成致密性Cu膜,可以有效地抑制电极内部贮氢合金的氧化,但对贮氢合金颗粒粉化的抑制作用不明显.在电解液中添加Cu(OH)2,增加了La2MgNi7.5Co1.5合金电极的活化次数,降低了该合金电极的高倍率放电性能,但对合金电极的最大电化学放电容量没有负面影响.此外,利用电沉积方法在电极表面镀Cu膜能够明显改善该合金电极的电化学循环稳定性.     

元素替代在制备La-Mg-Ni系贮氢电极合金中的应用

元素替代法是贮氢合金研究者常采用的一种提高贮氢合金电化学综合性能的重要研究方法。本文通过对近几年内La-Mg-Ni系贮氢合金的研究现状分析,综述了元素替代法在制备La-Mg-Ni系贮氢电极合金中的应用,并对La-Mg-Ni系贮氢合金将来的发展方向做出了预测。     

单层氧化锌有序孔膜的制备与性质

采用电化学沉积方法,结合胶体晶体模板,通过循环伏安方法对体系的电化学特性进行研究,获得一种良好的低沉积速度的制备工艺,即通过合适的电位恒电势法,最终获得了单层二维的氧化锌有序孔膜结构.对应于不同的沉积厚度,所得有序孔的形貌也会有所不同.通过扫描电子显微镜对该氧化锌有序多孔膜结构进行了表征,并研究了相应的光致激发特性,二维氧化锌有序多孔膜在384 nm表现出明显光致激发峰,激发峰的位置没有因单层有序孔阵列结构存在而有明显改变.     

Photocurrent generation properties of electrochemically polymerized terthiophene-linked fullerene film

Terthiophene derivative of C₆₀ fullerene was synthesized. The polymerized film of this fullerene analog was prepared on an indium–tin-oxide electrode by electrochemical polymerization at +1.4 V versus a Ag wire. The absorbance of the polymerized film was increased by increasing the electrochemical polymerization time. The polymerized film generated stable photocurrents in the presence of triethanolamine. Optimization of the amount of adsorbed polymerized film for improving the photoelectric conversion performance was achieved by controlling the polymerization time.     

温度对X80管线钢钝化膜电化学性能的影响

应用电化学阻抗谱（EIS）技术研究了温度对X80管线钢在模拟土壤环境中所成钝化 膜电化学性能的影响,同时应用点缺陷(PDM) 模型分析了温度对钝化膜电化学性能的影响。结果表明：随着成膜温度的升高,钝化膜的稳态电流增大,膜内施主密度增加,膜电阻、传递电阻及离子在膜内的扩散系数$D$减小,其原因在于温度升高,钝化膜内的氧空位数量增加。     

Polymer plating on AZ31 magnesium alloy surface and film evaluation of corrosion property

The polymeric thin film was prepared on the surface of AZ31 magnesium alloy by polymer plating of 6-dihexylamino-1,3,5-triazine-2,4-dithiol monosodium (DHN) in order to modify its surface feature and to improve its anti-corrosive property. Cyclic voltammetry was used to study the electrochemical reaction and film growth process of poly(6-dihexylamino-1,3,5-triazine-2,4-dithiol) (PDH) film, and the reaction peaks for film formation and growth were affirmed. The polymeric film weight was determined by electronic balance and its insoluble fraction in tetrahydrofuran was also measured. Contact angle meter was applied to test the surface wettability with distilled water drops at ambient temperature. It was found that the polymer-plated AZ31 alloy showed hydrophobic property with its distilled water contact angle up to 117.2°. The performance property of polymeric thin film formed on AZ31 surface was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in the corrosion solution of 3.5% NaCl. The electrochemical experiment results showed that polymer-plated thin film with hydrophobic and insulative characteristics could provide surface modification and an effective anti-corrosive protection to magnesium alloy substrate compared to the blank one.     

铜镍合金表面膜对其电化学行为的影响

<正> 一、引言 铜及铜基合金在含氯离子介质中,表面可形成一层氧化膜,许多研究工作者对此进行了大量的研究。Kruger考察了蒸馏水中铜表面膜的生长动力学。Blundy指出Cu-Ni合金表面膜的主要组份为Cu_2O,合金元素Ni、Fe不影响Cu_2O膜的结构。膜中也发现有少量的Cu_2(OH)_3Cl,有时发生偏聚,形成岛状沉积。关于膜的厚度,文献中报导不一,一般为几千埃。 目前多数人认为,铜及铜合金在含氯离子介质中的耐蚀性是由于表面生成的这一层氧化膜,但对这层膜影响金属腐蚀的具体机制研究得较少,多数文献只讨论了极化组抗Rp的变化。本文作者用电化学方法,结合表面分析结果,对铜镍合金B-30(以下简称B-30)生成表面膜过程中及生成表面膜后的电化学反应机制进行了讨论;对电化学极化过程,和浸泡过程中所形成的表面膜的性能进行了比较,对其差异进行了初步探讨。     

Exploring corrosion protection of Mg via ionic liquid pretreatment

We present the development of a 10-100 nanometer thick surface film upon pure Mg on exposure to an ionic liquid (IL) based on the bis(trifluoromethanesulfonyl)amide (TFSA) anion. This film formation is the result of the oxidative reactivity of the metal in the IL, with the subsequent effect of ultimately protecting the underlying metal from corrosion in aqueous chloride containing solution. Film formation was studied in the IL using an electrochemical droplet cell. It was seen that this film is adherent and subsequently facilitates appreciable protection against corrosion as judged by subsequent electrochemical testing in the form of potentiodynamic polarization and impedance spectroscopy, along with direct observation. The physical film morphology was studied by electron microscopy and focused ion beam.     

Electrochemical behavior of Cu-Zn-Al shape memory alloy after surface modification by electroless plated Ni-P

The electrochemical behavior of Cu-Zn-Al shape memory alloy (SMA) with and without electroless plated Ni-P was investigated by electrochemical methods in artificial Tyrode‘s solution. The results showed that Cu-Zn-Al SMA engendered dezincification corrosion in Tyrode‘s solution. The anodic active current densities as well as electrochemical dissolution sensitivity of the electroless plated Ni-P Cu-Zn-Al SMA increased with NaC1 concentration rising, pH of solution decreasing and environmental temperature uprising. X-ray diffraction analysis indicated that after surface modification by electroless plated Ni-P, an amorphous plated film formed on the surface of Cu-Zn-Al SMA. This film can effectively isolate matrix metal from corrosion media and significantly improve the electrochemical property of Cu-Zn-Al SMA in artificial Tyrode‘s solution.     

石墨烯掺杂对镁锂合金微弧氧化膜Cl?腐蚀敏感性的研究

为了研究添加石墨烯后镁锂合金微弧氧化膜在不同NaCl浓度下的腐蚀行为,通过向硅酸盐体系电解液中添加石墨烯,在镁锂合金表面制备出改性的MAO(Micro-arc oxidation)膜层,采用电化学极化曲线和阻抗谱方法研究改性膜层对NaCl溶液的腐蚀敏感性。结果表明:石墨烯的添加可有效改善由于微弧放电形成的孔洞及微裂纹等缺陷,提高膜层致密性和耐蚀性;改性的MAO膜层耐腐蚀性能随着NaCl溶液浓度的升高而降低,主要因为在较高的浓度梯度作用下,侵蚀性离子向膜层中扩散速率加快,进而加速了对MAO膜层的腐蚀破坏。     

Electropolymerization of indole and study of electrochemical behavior of the polymer in aqueous solutions

Polyindole was obtained by electrochemical polymerization of the monomer on glassy carbon electrode in aqueous solutions. The electrochemical behavior and the electroactivity of film were studied by cyclic voltammetry under various conditions. Here, an attempt was made to find more suitable electrochemical polymerization conditions such as number of potential cycles, potential scan rate, switching potential, acid and monomer concentration. The influence of the temperature of synthesis on the oxidation peak current was studied. As the temperature of synthesis is raised the rate of polymer formation increases linearly with the temperature from 0 to 50°C. The effect of the pH (buffer solutions) on the film response was also investigated. At pH>7, there is practically no response. However, the film is not destroyed and its response is recovered in acidic solution. Mechanisms of the redox process and the inactivation of polyindole are also discussed.