应用熔炼法制备含Li量为8.5%和14%的两种Mg-Li合金,分别由电势线性扫描、计时电流、交流阻抗和失重法等检测Mg-Li电极在NaCl溶液中的电化学特性,SEM观察其放电表面形貌.结果表明:Mg-14Li电极比Mg-8.5Li电极有较负的开路电位、更大的放电电流和较高的放电效率,但附着电极表面的疏松产物易于脱落.Mg-8.5Li电极的放电效率高于Mg-14Li电极的放电效率.两种电极在低恒电位放电电流效率均高于较高恒电位的放电电流效率.
The Mg-Li electrodes containing 8.5% and 14% Li were prepared using an induction melting method.Their electrochemical behavior in NaCl solution was investigated by means of potentiodynamic polarization,potentiostatic oxidation,electrochemical impedance technique and mass-loss measurements.The morphology of the electrodes after discharge was examined using scanning electron microscopy.The Mg-14Li electrode showed more negative open circuit potential and higher discharge current density than Mg-8.5Li electrode.The oxidation products of Mg-14Li loosely attached on the electrode surface and peeled off easily.The Mg-8.5Li exhibited higher utilization efficiency.Both electrodes gave higher utilization efficiencies when discharged at lower anodic potential.
[1]Medeiros M G,Bessette R R,Deschenes C M,et al.Magnesium-solution phase catholyte semi-fuel cell forundersea vehicles[J].J Power Sources,2004,136:226-231.
[2]Yang W,Yang S,Sun W,et al.Nanostructured palla-dium-silver coated nickel foam cathode for magnesium-hydrogen peroxide fuel cells[J].Electrochim Acta,2006,52:9-14.
[3]Hasvold O,Lian T,Haakaas E,et al.CLIPPER:Along-range,autonomous underwater vehicle using mag-nesium fuel and oxygen from the sea[J].J PowerSources,2004,136:232-239.
[4]Hasvold O.A magnesium-seawater power source for au-tonomous underwater vehicles[J].Power Sources,1993,14:243-255.
[5]Udhayan R,Muniyandi N,Mathur P B.Studies onmagneslum and its alloys in battery electrolytes[J].British Corrosion Journal,1992,27:68-71.
[6]Sivashanmugam A,Kumar T P,Renganathan N G,etal.Performance of a magnesium?lithium alloy as ananode for magnesium batteries[J].J Appl Electro-chem,2004,34:1135-1139.
[7]Cao D,Wu L,Sun Y,et al.Electrochemical behaviorof Mg-Li,Mg-Li-Al and Mg-Li-Al-Ce in sodium chlo-ride solution[J].J Power Sources,2008,177:624-630.
[8]Anik M,Celikten G.Analysis of the electrochemical re-action behavior of alloy AZ91 by EIS technique inH3PO4/KOHbuffered K2SO4solutions[J].Corros Sci,2007,49:1878-1894.
[9]Song G,Atrens A,Wu X,et al.Corrosion behaviour ofAZ21,AZ501 and AZ91 in sodium chloride[J].CorrosSci,1998,40:1769-1791.
[10]Baril G,Blanc C,Pebere N.AC impedance spectros-copy in characterizing time-dependent corrosion ofAZ91 and AM50 magnesium alloys characterizationwith respect to their microstructures[J].J ElectrochemSoc,2001,148:B489-B496.
