电沉积二氧化锰成核机理及其充放电性能

doi:10.11944/j.issn.1000-0518.2015.09.140446

摘要/Abstract

摘要：

采用计时电流法沉积纳米MnO₂电极材料,利用Scharifker-Hills成核理论模型分析时间-电流(i-t)曲线判断了MnO₂成核机理。对3种不同的成核方式制得的MnO₂材料进行电化学超级电容性能测试、用SEM观察了其微观形貌。比较了不同沉积方法对沉积材料结构、电容性能的影响。计时电流测试发现,在0.1 mol/L Mn²⁺溶液中,电势阶跃至0.365 V,初始成核符合瞬时成核机理,在0.01 mol/L Mn²⁺溶液中,电势阶跃至0.418 V,初始成核存在瞬时成核和连续成核两种不同机理,在0.5 mmol/L Mn²⁺溶液中,电势阶跃至0.515 V,初始成核则符合连续成核机理。超级电容性能测试发现,瞬时成核下制得的MnO₂电极材料相对于另外两种成核方式得到的电极材料具有更好的电容性能,这是因为瞬时成核更易于形成多孔、纳米片(棒)状等高比表面积的沉积物,表明制备方法影响MnO₂电极材料电容性能。

关键词: 二氧化锰, 电化学沉积, 成核机理, 超级电容

Abstract:

An ITO supported nanostructure manganese dioxide thin film electrode, fabricated by chronoamperometry was evaluated as a potential electrode for electrochemical capacitors. The nucleation mechanism was examined by fitting the experimental data(chronoamperometry) into the Scharifker/Hills nucleation models. SEM images of the electrodeposits show that the microstructure of manganese dioxide is affected by the deposition period. The capacity of the three kinds of manganese dioxide electrode materials formed by different nucleation mechanisms was investigated by cycle voltammetry, constant current charge-discharge method and AC impedance. The results show that the nucleation follows an instantaneous nucleation mechanism in the solution of 0.1 mol/L Mn²⁺ under a 0.365 V step potential, and mixed instantaneous and progressive nucleation mechanism in the solution of 0.01 mol/L Mn²⁺ under a 0.418 V step potential. The nucleation follows a progressive nucleation mechanism in the solution of 0.5 mmol/L Mn²⁺ under a 0.515 V step potential. It is obvious that the instantaneous nucleation is beneficial to preparing deposit sediment which has high specific surface area. Compare with other electrolytic deposit materials, this kind of material displays a better capacitance performance, implying that the capacitance performance can be influenced via different deposit approaches.

Key words: manganese dioxide, electrodeposition, nucleation mechanism, supercapacitor

冯谙,范利军,蔡陶,李文坡. 电沉积二氧化锰成核机理及其充放电性能[J]. 应用化学, 2015, 32(9): 1081-1087.

FENG An,FAN Lijun,CAI Tao,LI Wenpo. Electrodeposition of Manganese Dioxide: The Nucleation Mechanism and Capacitance Performance[J]. Chinese Journal of Applied Chemistry, 2015, 32(9): 1081-1087.

参考文献

[1]	Wang G,Zhang L,Zhang J. A Review of Electrode Materials for Electrochemical Supercapacitors[J]. Chem Soc Rev,2012,41(2):797-828.
[2]	Wei W F,Cui X W,Chen W X,et al.Manganese Oxide-based Materials as Electrochemical Supercapacitor Electrodes[J]. Chem Soc Rev,2011,40(3):1697-1721.
[3]	Subramanian V,Zhu H W,Vajtai R,et al.Hydrothermal Synthesis and Pseudocapacitance Properties of MnO2 Nanostructures[J]. J Phys Chem B,2005,109(43):20207-20214.
[4]	Xu M,Kong L,Zhou W,et al.Hydrothermal Synthesis and Pseudocapacitance Properties of Alpha-MnO2 Hollow Spheres and Hollow Urchins[J]. J Phys Chem C,2007,111(51):19141-19147.
[5]	Hu C C,Tsou T W. Ideal Capacitive Behavior of Hydrous Manganese Oxide Prepared by Anodic Deposition[J]. Electrochem Commun,2002,4(2):105-109.
[6]	Wei W,Cui X,Mao X,et al.Morphology Evolution in Anodically Electrodeposited Manganese Oxide Nanostructures for Electrochemical Supercapacitor Applications-Effect of Supersaturation Ratio[J]. Electrochim Acta,2011,56(3):1619-1628.
[7]	Hyde M E,Compton R G. A Review of the Analysis of Multiple Nucleation with Diffusion Controlled Growth[J]. J Electroanal Chem,2003,549:1-12.
[8]	Scharifker B,Hills G. Theoretical and Experimental Studies of Multiple Nucleation[J]. Electrochim Acta,1983,28(7):879-889.
[9]	Shamoto M,Mori K,Tomono K,et al.A Mechanistic Investigation on the Anodic Deposition of Layered Manganese Oxide[J]. J Electrochem Soc,2013,160(4):D132-D136.
[10]	Cross A D,Morel A,Hollenkamp T F,et al.Chronoamperometric Versus Galvanostatic Preparation of Manganese Oxides for Electrochemical Capacitors[J]. J Electrochem Soc,2011,158(10):A1160-A1165.
[11]	Rodrigues S,Munichandraiah N,Shukla A K. A Cyclic Voltammetric Study of the Kinetics and Mechanism of Electrodeposition of Manganese Dioxide[J]. J Appl Electrochem,1998,28(11):1235-1241.
[12]	Babakhani B,Ivey D G. Effect of Electrodeposition Conditions on the Electrochemical Capacitive Behavior of Synthesized Manganese Oxide Electrodes[J]. J Power Sources,2011,196(24):10762-10774.
[13]	Klejin S E F,Lai S C S,Koper M T M,et al. Electrochemistry of Nanoparticles[J]. Angew Chem Int Edit,2014,53(14):3558-3586.
[14]	Huynh M,Bediako D K,Liu Y,et al.Nucleation and Growth Mechanisms of an Electrodeposited Manganese Oxide Oxygen Evolution Catalyst[J]. J Phys Chem C,2014,118(30):17142-17152.
[15]	Mostany J,Mozota J,Scharifker B R. Three-Dimensional Nucleation with Diffusion Controled Growth.Part I.Number Density of Active Sites and Nucleation Rates per Site CARBON[J]. J Electroanal Chem,1984,177(1/2):25-37.
[16]	Bard A J,Faulkner L R. Electrochemical Methods Fundamentals and Applications[M]. Wiley New York,1980:216-218.
[17]	Conway B E. Electrochemical Supercapacitors[M]. New York:Kluwer Academic,1999:525-556.
[18]	Dupont M,Hollenkamp A F,Donne S W. Electrochemically Active Surface Area Effects on the Performance of Manganese Dioxide for Electrochemical Capacitor Applications[J]. Electrochim Acta,2013,104:140-147.
[19]	Babakhani B,Ivey D G. Anodic Deposition of Manganese Oxide Electrodes with Rod-like Structures for Application as Electrochemical Capacitors[J]. J Power Sources,2010,195(7):2110-2117.
[20]	Chou S,Cheng F,Chen J. Electrodeposition Synthesis and Electrochemical Properties of Nanostructured Gamma-MnO2 Films[J]. J Power Sources,2006,162(1):727-734.
[21]	Hu C C,Wang C C. Nanostructures and Capacitive Characteristics of Hydrous Manganese Oxide Prepared by Electrochemical Deposition[J]. J Electrochem Soc,2003,150(8):A1079-A1084.
[22]	Dupont M F,Hollenkamp A F,Donne S W. Large Amplitude Electrochemical Impedance Spectroscopy for Characterizing the Performance of Electrochemical Capacitors[J]. J Electrochem Soc,2014,161(4):A648-A656.
[23]	Chen Y,Wang J W,Shi X C,et al.Pseudocapacitive Characteristics of Manganese Oxide Anodized from Manganese Coating Electrodeposited from Aqueous Solution[J]. Electrochim Acta,2013,109:678-683.