冰晶石熔盐中阳极效应时石墨阳极的电化学行为(英文)

在1000℃下采用循环伏安法研究石墨阳极在冰晶石氧化铝熔盐中的阳极电化学行为。讨论了循环伏安曲线中较高的电流峰。结果表明,在高电位条件下,一种含氧氟络合阴离子中的氟与碳阳极反应,且在阳极表面生成一层高电阻的CF膜。在含0.5%氧化铝的电解质中,石墨电极钝化电位为3.28V,并随着氧化铝含量的增加而增大。这一现象表明,在冰晶石-氧化铝熔盐体系中氧化铝含量对阳极过程起着主导作用。     

Al-Zn-Sn-Ga阳极腐蚀过程的电化学阻抗谱

通过测定Al-Zn-Sn-Ga阳极在3.5%NaCl(质量分数)溶液中浸泡不同时间的电化学阻抗谱(EIS),研究该阳极的腐蚀发展过程和腐蚀特征。结果显示:当合金刚被浸入3.5%NaCl溶液时,EIS谱为反应电阻很大的容抗弧,表明此时合金处于钝化态;随着浸泡时间的延长,EIS谱中高频段的容抗弧明显减小且低频段出现感抗弧,合金进入点蚀期;继续延长浸泡时间,EIS谱中除高频段的容抗弧和中、低频段感抗弧外,在低频段出现另一容抗弧,合金处于点蚀扩展期;随着浸泡时间的继续增加,低频段感抗弧消失,EIS谱由两个容抗弧组成,合金达到均匀腐蚀期。因此,合金的腐蚀由钝化态开始,经点蚀期和点蚀扩展期,达到均匀腐蚀期。     

Electrochemical properties of some cobalt antimonides as anode materi-als for lithium- ion batteries

Some cobalt antimonides have been prepared and studied as the candidate anode materials for lithium ion batter-ies. Reversible capacities of 424,423 and 546 mA·h·g-1 were measured at the first cycle for as-solidified CoSb2, CoSb3 and annealed CoSb3 respectively. A low lithium ions diffusion coefficient in the order of 10-16 m2·s-1 was estimated from the coulometric titration measurements in the annealed CoSb3 electrode. It was found that the electrochemical properties of fine powders are significantly better than coarse powders. However the SEM picture shows that the nano-sized CoSb3 powders gathered to larger granules, which worsens somewhat the capacity retention of the nano-sized materials, although the volume capacities of the annealed and ball milled CoSb3 remain near twice of that of graphite after 50 cycles.     

预处理对热电池阳极材料LiB合金结构和性能的影响

在LiB合金材料的制备中加入冷挤压和热处理两步预处理工艺;采用X射线衍射仪、扫描电镜测试合金的物相组成和微观组织;研究了预处理工艺对材料的密度、硬度、力学性能、热稳定性和放电性能的影响。结果表明:相对直接轧制方法制备的LiB合金材料,采用预处理工艺,提高了合金材料中Li7B6的相对含量,同时使合金结构和成分更均匀、致密,从而提高了合金的密度、硬度,合金的抗拉强度和断裂延伸率也显著提高;预处理使材料骨架孔洞缩小而且分布均匀,因此也促进了材料热稳定性的提高;材料的放电性能显著提高,放电容量由5 244提高至6 552 C/g。此外,与直接轧制工艺相比,采用冷挤压和热处理两道预处理工艺减少了多孔的合金锭与可反应气氛接触的时间,防止了氧化作用,消除了开裂、麻点等缺陷,大大提高了材料的加工成材率,使其成材率由不到50%提高至70%以上。     

Influence of Ga and Hg on microstructure and electrochemical corrosion behavior of Mg alloy anode materials

The effects of Hg and Ga on the electrochemical corrosion behavior of Mg-5%Hg （molar fraction） alloys were investigated by the measurement of polarization curves and galvanostatic test. The microstructure of the alloys and the corroded surface of the specimens were investigated by scanning electron microscopy, X-ray diffractometry and emission spectrum analysis. It can be concluded that the addition of l%Ga （molar fraction） reduces corrosion current density from 26.98 mA/cm^2 to 2.34 mA/cm^2; while the addition of l%Hg （molar fraction） increases corrosion current density. The addition of Ga and Hg both promotes the electrochemical activity of the alloys and the influence of Ga is more effective than Hg. Mg-5%Hg-l%Ga alloy has the best electrochemical activity, showing mean potential of-1.992 V. The activation mechanism of the magnesium alloy produced by Hg and Ga was put forward. Magnesium atoms are dissolved in liquid Hg and Ga to form amalgam and undergo severe oxidation at the amalgam/electrolyte interface.     

AZ31与NZ30K合金作为镁电池负极材料的电化学性能

采用恒温浸泡、交流阻抗和极化曲线法分别研究铸态(F)和固溶态(T4)的NZ30K以及挤压态AZ31镁合金在不同浓度MgCl2、MgSO4、Mg(COOCH3)2、MgBr2溶液中的腐蚀行为和电化学性能.结果表明随着电解液中电解质浓度的增加,3种镁合金的自腐蚀速率均增大.F态和T4态的NZ30K合金在MgSO4溶液中腐蚀速率最快,在MgBr2溶液中耐蚀性能最好,而AZ31合金在MgCl2溶液中耐蚀性能最差,在MgSO4和Mg(COOCH3)2中具有较好的耐蚀性能.电化学阻抗谱(EIS)结果表明在4种电解液中,镁合金的高频端容抗环半径均随着电解质浓度的增加而减小,这与恒温浸泡的实验结果相吻合.     

碱溶液中添加剂对铝阳极行为的影响

为了提高铝活化性能以及降低析氢腐蚀,用电化学方法研究了在4mol／LKOH溶液中,添加剂酒石酸钾钠（C4H4O6KNa）、邻氨基苯酚（NH2C6H4OH）以及复合添加剂对铝阳极（W（AJ）=99．999％）电化学行为的影响。结果表明：C4H4O6KNa对抑制铝的析氢腐蚀作用不大,但大幅度提高铝阳极的活性。添加NH：C6H40H,主要作用是大幅度抑制铝的析氢腐蚀,对铝活性几乎无影响。复合添加剂（C4H4O6KNa＋NH2C6H4OH＋KMnO4）能明显降低铝阳极在碱性介质中的极化,提高其活性,同时析氢腐蚀也降低,其最佳配方为：15mmol/L C4H4O6KNa＋0．4mol／LNH2C6H4OH＋0．8mmol／LK2MnO4。     

Electrochemical behavior of electroplated Zn-P alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＥｌｅｃｔｒｏｐｌａｔｅｄＺｎ Ｐｃｏａｔｉｎｇｓｅｘｈｉｂｉｔａｒａｎｇｅｏｆｆａｓｃｉｎａｔｉｎｇｐｒｏｐｅｒｔｉｅｓ ,ｓｕｃｈａｓｈｉｇｈｃｏｒｒｏｓｉｏｎｒｅｓｉｓ ｔａｎｃｅ ,ｅｘｃｅｌｌｅｎｔ ｐａｉｎｔａｂｉｌｉｔｙａｎｄ ｐｈｏｓｐｈｏｒａｔａｂｉｌｉｔｙ ,ｆｉｎｅｗｅｌｄａｂｉｌｉｔｙａｎｄｆｏｒｍａｂｉｌｉｔｙ[1] .Ｔｈｅｒｅｆｏｒｅ ,ｉｎｒｅ ｃｅｎｔｙｅａｒｓ ,ｔｈｅｒｅｈａｖｅｂｅｅｎｓｅｖｅｒａｌｉｎｖｅｓｔｉｇａｔｉｏｎｓｏｎｐｒｅｐａｒｉｎｇ…     

The attack initiation of Al-Zn-In-Sn anode by the segregation concentrating Zn,Sn and In

The microstructure of Al–5%Zn–0.025%In-0.15%Sn anode was investigated by EPMA, and EDAX. The result showed that the microstructure at the Al-Zn-In-Sn anode can be categorized into two different types, namely the catenulate segregation enriched in Zn, Fe, Si, and the elliptical or rounded segregation where Zn, Sn, In concentrated. In order to explain the initial dissolution of the aluminum anode, the electrochemical behavior in 3% NaCl solution of the Al-Zn-In-Sn anode and its simulated segregation concentrating Zn, Sn, In were tested using potentiodynamic polarization and electrochemical impedance spectroscopy. The result showed that the simulated segregation concentrating Zn, Sn, In would preferentially be dissolved into the solution as the anode of galvanic cell.     

Electrochemical properties of AB5 type hydrogen storage alloy as anode electrocatalyst of PEMFC

1　INTRODUCTIONIn recent years, the application of the roomtemperature type ( < 100 ℃) polymer electrolytemembrane fuel cells(PEMFCs) as a primary powersource in electric vehicles and portable equipmentsetc has received increasing attention[1 4]. Usuallyin a PEMFC system, platinum is chosen as the e lectrode electrocatalyst, however, it results in ahigh cost PEMFC system for commercialization be cause Pt is a high cost, source limit metal. So,looking fo…     

Bi含量对Al-Zn-Ga-Si-Bi合金电化学性能和腐蚀形貌影响

通过在Al-Zn-Ga-Si低电位牺牲阳极材料中添加Bi来改善阳极的性能，以不同Bi含量制备了5种牺牲阳极材料。通过电化学性能测试、极化曲线以及电化学阻抗谱测试来分析Bi对阳极电化学性能的影响；采用三维视频和宏观表征来分析Bi对阳极腐蚀形貌的影响。结果表明，添加适量Bi可以有效破坏铝合金阳极表面的氧化膜，提高阳极活化性能，并减少晶界腐蚀的作用，改善阳极的溶解形貌，但Bi含量过高时反而降低阳极的均匀活化性能，当Bi含量为0.05%(质量分数) 时阳极综合性能良好，可用作高强钢的阴极保护。     

Lithium-ion-storage behaviours of CoSb_3 intermetallic compound and effects of some carbonaceous additives

1　ＩＮＴＲＯＤＵＣＴＩＯＮＬｉｔｈｉｕｍｉｏｎｃｅｌｌｓｃｕｒｒｅｎｔｌｙｒｅｐｒｅｓｅｎｔｔｈｅｓｔａｔｅ ｏｆ ｔｈｅ ａｒｔｉｎｓｍａｌｌｒｅｃｈａｒｇｅａｂｌｅｂａｔｔｅｒｉｅｓｄｕｅｔｏｔｈｅｉｒｈｉｇｈｖｏｌｔａｇｅ ,ｈｉｇｈｅｎｅｒｇｙｄｅｎｓｉｔｙ ,ａｎｄｌｏｎｇｌｉｆｅ ,ｃｏｍｐａｒｅｄｗｉｔｈｃｏｎｖｅｎｔｉｏｎａｌｒｅｃｈａｒｇｅａｂｌｅｂａｔｔｅｒｉｅｓ .Ｔｈｅｔｅｃｈｎｏｌｏｇｙｉｓｂａｓｅｄｏｎｔｈｅｕｓｅｏｆｓｕｉｔａｂｌｙｃｈｏｓｅｎｌｉｔｈｉｕｍｉｎｔｅｒｃａｌａ…     

Al-Zn-Sn-Ga合金点蚀行为及扩展机理

通过分析Al-7Zn-0.1Sn-0.015Ga(质量分数,％)合金在3.5％ NaCl溶液中的点蚀形貌及电化学阻抗谱(EIS)研究该合金的点蚀行为及扩展机理.结果表明:该合金析出相界面处由于Cl-吸附和微电池的共同作用优先溶解引发点蚀.蚀孔内金属离子浓度增加,Cl-向孔内迁移导致孔内Cl-浓度升高,同时孔内金属离子水解使孔内H+浓度升高,蚀孔迅速纵深发展.随着析出相溶解及孔深增加,腐蚀产物在蚀孔处堆积造成金属离子传质阻力增大,产生浓差极化导致蚀孔底部电位正移,纵向腐蚀速率减慢;回沉积在蚀孔处的Ga和Al形成Ga-Al汞齐,分离氧化膜使铝基体不断溶解,也使腐蚀产物不断脱落,使点蚀坑横向扩展.     

Electrochemical behavior of Ti-Ni shape memory alloy in fibrinogen solution

Electrochemical behaviors of Ti-Ni shape memory alloy in fibrinogen solution were studied by electrochemical techniques. The results indicate that the addition of the fibrinogen has no obvious effect on the corrosion potential, but decreases the pitting potential markedly and increases the passive current densities. The analysis of energy-dispersive X-ray for samples adsorbing fibrinogen exhibits that the elements of O, C and N exist on the surface of Ti-Ni alloy. Furthermore, the scanning electron microscope micrographs confirm that the configuration of the adsorbing fibrinogen concentrating on surface defects is like cluster and the fibrinogen adsorption concentration is 96.67 mg/m^2 through ultroviolet ray absorption method. Fibrinogen combined with Ti-Ni alloy surface by complex band and its electrochemical transfer accelerated the corrosion of alloy.     

Mg对Al-Zn-Sn阳极合金组织与电化学性能的影响

为提高Al-7Zn-0.1Sn(质量分数,%)牺牲阳极的电化学性能,采用扫描电镜(SEM)、透射电镜(TEM)、动电位极化、电化学阻抗等方法,研究了不同含量的Mg对Al-7Zn-0.1Sn合金微观组织和电化学性能的影响。结果表明:Mg可使Al-7Zn-0.1Sn合金从粗大枝状晶向等轴晶转变;适量Mg可改善Al-7Zn-0.1Sn合金的电化学性能;随着Mg含量增加,合金电位负移、电流效率逐步提高;当Mg含量为2%时,合金具有最好的综合电化学性能。     

Al-Zn-In-Si牺牲阳极在模拟海水及海泥环境中的电化学性能

目的 分析A13型Al-Zn-In-Si牺牲阳极在海水、海泥中的电化学性能.方法 采用恒电流极化进行4 d的加速实验,使用电化学阻抗谱(EIS)分析电化学腐蚀过程,通过扫描电子显微镜(SEM)、能谱分析(EDS)及三维超景深显微镜观察分析腐蚀形貌及表面化学成分,对比研究了Al-Zn-In-Si牺牲阳极在模拟海水和海泥环境下的腐蚀形貌、电化学性能.结果 在模拟海水和海泥环境中,尽管Al-Zn-In-Si牺牲阳极都满足DNVGL-RP-B401的要求,但在海泥环境中,其电化学效率仅为65.97％,远低于海水环境中的89.43％.牺牲阳极在海水环境中发生均匀腐蚀,而在海泥环境中却呈现严重的不均匀腐蚀现象,表面腐蚀坑为疏松多孔蜂窝状.结论 在海泥环境下,Al-Zn-In-Si牺牲阳极的腐蚀产物扩散困难,局部呈现腐蚀坑,自腐蚀速率高,导致电化学效率降低.溶解过程中,由于组织脱落,自身消耗增加,电化学容量降低,从而导致阳极在模拟海泥环境中的电化学性能低于海水环境,并揭示了阳极在模拟海水、海泥环境中的腐蚀机理.     

Electrochemical behavior of YAG laser-welded NiTi shape memory alloy

Electrochemical behaviors of laser-welded Ti-50.6%Ni（mole fraction） shape memory alloy and the base metal in 0.9% NaCl solution were investigated by electrochemical techniques as corrosion potential measurement, linear and potentiodynamic polarization. The results indicate that the laser-welded NiTi alloy is less susceptible to pitting and crevice corrosion than the base metal, which is demonstrated by the increase in polarization resistance（Rp） and pitting potential（φpit） and decrease in corrosion current density（Jcorr） and mean difference between φpit and φprot values. It is confirmed by scanning electron microscope micrographs that pits could be observed on the surface of base metal but not on the surface of laser-welded alloy after potentiodynamic tests. An improvement of corrosion resistance of laser-welded NiTi alloy could be attributed to almost complete dissolution of inclusions upon laser welding.     

Electrochemical behavior of SUS316L stainless steelafter surface modification

1　INTRODUCTIONAsametallicimplantdevice ,coronarystentsneedgoodmechanicalperformance ,wonderfulanti corrosionbehavioraswellasbloodcompatiblecapabil ityforinvivoenvironments.Nowadaysthestentsaremadebyausteniticstainlesssteel,cobalt basedalloy ,titaniumanditsalloy[1] .Amongthesematerials ,SUS316Lstainlesssteelisthemostcommonusedonebecauseofitscheapcost ,goodmechanicalbehaviorandlowcorrosionrate .Itdoeshowever ,frequentlycorrodeinthebody ,andreleasesomenoxiousionssuchasCr,Ni,Moions .Theio…     

Hg和Ga元素对Mg阳极材料组织和电化学腐蚀性能的影响(英文)

采用动电位极化、恒电流和交流阻抗测试方法研究了Hg和Ga元素对Mg2%Hg,Mg2%Ga和Mg2%Hg2%Ga合金电化学腐蚀性能的影响,并用扫描电镜、X射线衍射和能谱分析了上述合金的显微组织和腐蚀表面形貌。结果表明:Mg2%Ga合金是固溶体,Mg-2%Hg和Mg-2%Hg2%Ga合金的晶界有白色第二相。Mg-2%Ga合金的平均电位为1.48V,腐蚀电流密度为0.15mA/cm2,电化学活性差,耐腐蚀性能好。Mg-2%Hg-2%Ga合金的平均电位1.848V,腐蚀电流密度为2.136mA/cm2,电化学活性好,耐腐蚀性能差。MgHgGa合金的活化机制是Hg和Ga原子的溶解沉积。     

三种铝合金阳极的电化学性能对比

通过测试三种铝阳极的电化学效率、电位以及交流阻抗与极化曲线,对三种铝阳极进行了优选.