本文简要介绍了实验室内有关利用共焦显微拉曼光谱于某些实用电极材料 (表面 )性能研究的结果 .具体的研究实例包括 :尖晶石锂锰氧化物中Li+ 的嵌入 脱出过程 ,AB5 型金属氢化物电极表面氧化物的性能和钢筋电极表面钝化膜及其孔蚀过程 .Some recent research work about applications of confocal Raman micro spectroscopy for study of practical electrode materials carried out in our lab has been briefly introduced. The examples include study of electrochemical Li + intercalation process, characterization of surface oxide film on AB 5 type electrodes and passive film and pitting corrosion of Rebar electrodes.作者联系地址：厦门大学固体表面物理化学国家重点实验室!化学系,物理化学研究所,福建厦门361005,厦门大学固体表面物理化学国家重点实验室!化学系,物理化学研究所,福建厦门361005,厦门大学固体表面物理化学国家重点实验室!化学系,物理化学研究所,福建厦门361005,厦门大学固体表面物理化学国Author's Address: State Key Lab for Phys. Chem. of Solid Surface, Xiamen Univ., Xiamen, 361005,Chin

CHEN X G

LIN Z G

NAN J M

YANG Y CHU W

储炜

南俊民

杨勇

林祖赓

陈旭光

Xiamen University Institutional Repository

第 7 卷 　第 1 期2001 年 2 月电化学EL ECTROCHEMISTR YVol. 7 　No. 1Feb. 2001Article ID :100623471 (2001) 0120030207The Applications of Confocal Raman Micro2Spectroscopyfor study of practical electrode materialsYAN G Y3 CHU W , NAN J M , CHEN X G , L IN Z G( S tate Key L ab f or Phys . Chem . of Solid S urf ace , Xiamen U niv . , Xiamen , 361005 , China)Abstract : Some recent research work about applications of confocal Raman micro2spectroscopy for study of practical electrode materials carried out in our lab has beenbriefly introduced. The examples include study of electrochemical Li +2intercalation pro2cess , characterization of surface oxide film on AB52type electrodes and passive film andpitting corrosion of Rebar electrodes.Key words : Li +2intercalation electrodes , spinel LiMn2O4 electrodes , AB52typemetal2hydride electrodes , surface oxide film , pitting corrosion , Rebar elet rodes , confo2cal Raman spectroscopy1CLC Number : O 646 , O 433 　　　　　　　Document Code : A1 　IntroductionTo understand relationship between structure and properties of electrode material or surfacefilms on the electrodes is a very important subject in electrochemical field. Raman spectroscopictechnique is a very useful tool to investigate the vibrational properties of electrode materials suchas metal2oxide system especially at low frequency region where strong absorption of water occursin far2inf rared region. In the last few years , we have explored to use confocal Raman micro2spec2t roscopy for study of some important practical electrode materials or surface oxide films on theelectrodes[1～5 ] which they are widely used as batteries’electrodes or construction materials i. e.Rebar in cement . Some useful information has been obtained for understanding of composition ofthe surface species formed during the electrode reactions in these electrochemical systems. In thispaper , some results about our studies will be briefly reviewed mainly based on our lab’s researchReceived date : 18 Oct . 20003 　Corresponding authorFoundation item : Projects were supported by National Natural Science Foundation of China ( No. 29925310 ,29833090 , 29673003)© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.network . The detailed results and discussed can be found in the published or the following to be pub2lished papers12 　ExperimentalDetailed description of electrode materials , chemical reagent , pret reatment conditions can befound in the literature[1～5 ] . Most of electrochemical measurements were performed by PARC263/ 273 A potentiostat/ gavalnostat ( PARC , USA) or IM6 impedance spectrum analyzer ( ZAH2N ER2elektrik , Germany) . Raman experiments were carried out with a Confocal Microprobe Ra2man system (Labrum I from Dilor , France) . The excitation light was from an air2cooled He2Nelaser (623. 8 nm) . According to different experiments , the laser power is different . e. g. inLixMn2O4 experiments , the laser power is better less than 1mW , however , in metal2hydride elec2t rode system , the laser power can be higher at about 13 mW. The diameter of the laser spot wascontrolled at 1～10μm.3 　Results and Discussion3. 1 　Raman spectroscopic study of Li2deintercalation process　　 in spinel LixMn2O4 materials[ 1～2]　　In the first system , st ructural changes of the spinel electrode materials LixMn2O4 doping　Fig. 1 　In situ Raman spectra of LixMn2O4 at dif2ferent potentials in 1 mol/ L LiClO4/ PC +DME. The electrode potential and possibleorigin of Raman peaks for PC solvent arealso labelled in the figurewith different amount of Li + ions and during theelectrochemical intercalation/ de2intercalation cy2cles have been investigated. It has been shownthat ex2situ confocal Raman spectroscopy can sen2sitively distinguish the different phases between 0< x < 0. 5 and 0. 5 < x < 1 in spinel LixMn2O4 atpeak around 620 cm - 1 . In electrochemically mod2ulated Raman spectroscopy ( see Fig. 1 ) , thechanges of the peak around 590 cm - 1 shows thatthere are two steps in Li + intercalation/ de2inter2calation reactions of LixMn2O4 ( see Fig. 2 ) .Based on the theoretical analysis[6 ] and literatureresults[7 ] , The peaks at 620 cm - 1 and 590 cm - 1are att ributed to the T2g and A1g vibration mode ofMn 3 . O bond inλ2MnO2 . In addition , as de2creasing of the electrode potential , i . e. as interca2lation of Li + intoλ2MnO2 lattice , the Raman peakshifts to lower frequency , this result indicate that the intercalation of Li + into LixMn2O4 not onlyweakens the Mn2O bond but also causes the expansion of the crystal lattice. Thus it can be ob2served that the Raman shift moves to lower frequency and increase of lattice parameters which cal2·13·第 1 期 　　　　　　　杨 　勇等 :实用电极材料体系的共焦显微拉曼光谱研究© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.netculated from XRD data respectively.3. 2 　Raman spectroscopic study of surface oxide f ilm on　　AB52type metal hydride electrodes[ 3～4]　　In the second system , the structural changes of surface oxide film on metal2hydride electrodes　Fig. 2 　Potential2dependence of the Raman peak for Mn2Obond at around 590 cm - 1have been characterized by using in2situand ex2situ Raman micro2spectroscopy.On the basis of Raman and electrochemi2cal experimental results , it is concludedthat nickel played a primary role in thecomposite surface oxide layer formed onthe surface layer of MH electrode. Onthe other hand , based on in2situ and mi2croscopic Raman results , it is alsodemonstrated that La , Co , Mn and otheralloy components segregated and enrichedprogressively to alloy surface layer due totheir affinity with water , and subse2　Fig. 3 　In2situ Raman spectra for activated MH electrode at dif2ferent sampling spots , A : sampling spot with crack , B :sampling spot without visible crack , 1) : - 0. 2 V , 2) :0. 2 V , 3) : 0. 35 Vquently produced oxides during charge2discharge processes. Fig. 3 showstwo Raman spectra of “activated”electrodes , one is the spectra of sur2face oxide film on crack site , anotheris the spectra of surface oxide film onsmooth site on the electrode surface ,based on the literature results[8～12 ]and our own results besides some ofRaman peaks at 474. 6 and 555. 6cm - 1 are assigned to the formation ofhigher valence nickel oxides from itsdivalent oxide , four weaker and lesswell2defined Raman peaks ( i. e.430. 2 , 494. 1 , 597. 8 and 635. 8·23· 电 　化 　学 2001 年© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.net　Fig. 4 　A : Raman spectra for the powder MH electrode after 500charge2discharge cycles at open2circuit potential at differentsampling spots ; B : Raman spectra for mixture bindercm - 1) are also primarily ascribed.i. e. the peaks at 430 cm - 1 and597. 8 cm - 1 to Co (OH) 2 and CoO ,and the peaks at 494. 1 cm - 1 and635. 8 cm - 1 to Mn ( OH ) 2 andMnO. It also indicates that the dif2ference in composition betweencrack and smooth sites on the elec2t rode surface.In addition , confocal Ramanmicroscopy has also been exploredfor study of powder MH electrodes.It is shown that non2uniform dist ri2bution of oxides on different alloyparticles. Fig. 4 shows some Ra2man spectra of practical powder electrodes after 500 charge2discharge cycles. It shows that differ2ent composition of surface oxide on each alloy particles and can even look at mixture binders by us2ing confocal Raman microscopy.3. 3 　Raman spectroscopic study of passive f ilms on carbon steel ( Rebar) electrodes　　 in simulated cement solutions[ 5]　　In the third system , microprobe Raman spectroscopy and photoelectrochemical microscopy (PEM ) were combined and applied in studying the composition and local electronic properties ofthe passive film on the REBAR electrode surface formed in simulated cement pore solution. Al2though some normal Raman spectroscopy have been used[13～15 ] in the study of passive films oniron electrodes in acid or alkaline solutions , however , confocal Raman microscopy have not beenused in the study of passive films on Rebar electrodes before this work. Two growth2modes ofpassive films such as potential2scanning2 and single2potential2step growth modes have been investi2gated and compared. Fig. 5 shows a set of Raman spectra of surface oxides which formed in twogrowth modes and at pristine state. It indicates that two2type of passive films with differentst ructure and compositions are formed by these two growth modes. For example , it has beendemonstrated that a amorphous film mainly containing ferrous2oxides which was formed by single2potential step polarization , however , a multi2layer st ructure oxide film which was formed by po2tential2scanning (or oxidation2reduction cycles , ORC) method. The formation and transformationof the films under different electrochemical conditions are discussed based on our results. In addi2tion , we have also explored the advantages of the confocal Raman microscopy in the study of spa2·33·第 1 期 　　　　　　　杨 　勇等 :实用电极材料体系的共焦显微拉曼光谱研究© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.nettial dist ribution of passive film formed during localized corrosion such as pitting corrosion process2es. Fig. 6 shows a CCD image of pitting corrosion of Rebar electrode in simulated cement pore so2lution (p H = 12. 5) containing 10 % NaCl. The black region represents corrosive pit . Fig. 7a shows·43· 电 　化 　学 2001 年© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.neta comparison of Raman spectra of oxide film between pit site and without pit site. In addition ,the profiles of“line scanning”by collecting of spectral line at 407. 5 and 718. 8 cm - 1 along thepoint 1 to point 2 in Fig. 6 are also shown in Fig. 7b and 7c. It is clearly seen that different dist ri2bution of surface oxide species in the passive films on corrosive electrodes.Acknowledgements :The authors are grateful for the financial support f rom National Science Foundation ( No.29673003 29833090) and New Material Division of National High2Technology Research and De2velopment committee. We would like to thank Prof . Z. Q. Tian , Dr. B. Ren , Mr. Q. J .Huang , Ms. X. Q. Li , Mr. J . L . Yao for assistance with Raman experiments. Y. Yang wouldalso like to thank additional financial support f rom NSFC(No. . 29925310) for an excellent youngscholar research award and additional support f rom department of education , PRC.Reference s :[ 1 ] 　Chu W. Structure , performance and characterization of manganese nodule , LiMn2O4 and other cathode mate2rials for lithium ion batteries[D ] . . Xiamen University , 1999.[ 2 ] 　Chu W , Zhang Z R , Liu Z T , Yang Y , Lin Z G. In- situ and ex- situ Raman spectroscopic characterization ofLi + -intercalation processes and structural changes of spinel or modified spinel materials[ C] , in“Micro PowerSources”edited Zaghib K and Surampudi S , PV2000-3 , The Electrochemical Society Inc , 125.[3 ] 　Nan J M1 Effects of surface pppretreatment on surface properties and performances of AB5- type hydrogenstorage alloy electrode for MH/ Ni Battery[D ] . Xiamen University , 1998.[4 ] 　Nan J M , Yang Y , You J K , Li X Q , Lin Z G. In- situ and ex- situ characterization of surface oxide films onAB52type metal- hydride electrodes[J ] . J . Alloys and Compounds , 1999 , 293 - 295 :747.[5 ] 　Chen X G. The Composition , structure and in- situ spectroscopic characterization of passive films on iron- basedelectrodes[D ] . Xiamen University , 1997 : b) Chen X G , Yang Y , Lin Z G. In- situ spectroscopic and scan2ning probe microscopic characterization of passive films on iron- based electrodes , in proceeding of symposiumon“passivity and breakdown”, The Electrochemical Society Inc[ C] . 1997 :180～1841[ 6 ] 　Ammundsen B A , Burns G R , Roziere J , et al. Lattice dynamics and vibrational spectra of lithium manganeseoxide : A computer simulation and spectroscopicstudy[J ] . J . Phys. Chem. B. 1999 ,103 :5 1751[7 ] 　Huang W , Frech R. In- situ Raman spectroscopic studiess of electrochemical intercalation in LixMn2O4- basedcathodes[J ] . J . Power Sources , 1999 :81～82.[8 ] 　J . F. Jackovitz. Proceedings of the Symposium on the Nickel Electrode [ C ] . edited by R. G. Gunther , S.Gross. The Electrochem. Soc. Inc. , Pennington , N J , PV82～4 , 48～68.[9 ] 　Cornilsen C , Karjala P J , Loyselle P L . Structural comparison of nickel electrodes and precursor phases[J ] .J . Power Sources , 1990 ,22 :351 and reference therein.[ 10 ] 　Melendres C A , Paden W , Tani B , Walczak W. On the structure of the higher oxide forms of nickel[J ] . J .Electrochem. Soc. , 1987 ,134 :762.·53·第 1 期 　　　　　　　杨 　勇等 :实用电极材料体系的共焦显微拉曼光谱研究© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.net[11 ] 　Melendres C A , Pankuch M. On the composition of the passive film on Nickel : a surface-enhanced Ramanspectroelectrochemical study[J ] . J . Electroanal. . Chem. , 1992 ,333 :103.[ 12 ] 　Maslar J E , Hurst W S , Bowers W J , et al. In- situ Raman spectroscopic investigation of aqueous iron corro2sion at elevated temperatures and pressures[J ] . J . Electrochem. Soc. , 2000 , 147 :2 532.[ 13 ] 　Odziemkowski M , Flis J , Irish D E. Raman spectral and electrochemical studies of surface film formation oniron and its alloys with carbon in Na2CO3/ NaHCO3 solution with reference to stress corrosion cracking[J ] .Electrochim. Acta , 1994 , 39 : 2 225.[14 ] 　Hugot2Le Goff A , Flis J , Boucherit N , Joiret S , Wilinski J . Use of Raman spectroscopy and rotating splitring disk electrode for identification of surface layers on Iron in 1M KOH[J ] . J . Electrochem. Soc. , 1990 ,137 :2 684.[ 15 ] 　Thierry D , Persson O , Leygraf C , Boucherit N , Hugot-Le Goff A. Raman spectroscopy and XPS investiga2tion of anodic corrosion films formed on Fe- Mo alloys in alkaline solutions[J ] . Corros. Sci. , 1991 , 32 :273.实用电极材料体系的共焦显微拉曼光谱研究杨　勇 3 , 储　炜 , 南俊民 , 陈旭光 , 林祖赓(厦门大学固体表面物理化学国家重点实验室 , 化学系 ,物理化学研究所 , 福建 厦门 　361005)摘要 : 　本文简要介绍了实验室内有关利用共焦显微拉曼光谱于某些实用电极材料 (表面) 性能研究的结果. 具体的研究实例包括 : 尖晶石锂锰氧化物中 Li + 的嵌入2脱出过程 , AB52型金属氢化物电极表面氧化物的性能和钢筋电极表面钝化膜及其孔蚀过程.关键词 : 　Li + 的嵌入2脱出过程 ;尖晶石锂锰氧化物 ; AB52型金属氢化物 ;表面氧化物 ; 钢筋电极 ;孔蚀过程 ;共焦显微拉曼光谱·63· 电 　化 　学 2001 年© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.    http://www.cnki.net

The Applications of Confocal Raman Micro-Spectroscopy for study of practical electrode materials

http://dspace.xmu.edu.cn/bitstream/handle/2288/57623/%e5%ae%9e%e7%94%a8%e7%94%b5%e6%9e%81%e6%9d%90%e6%96%99%e4%bd%93%e7%b3%bb%e7%9a%84%e5%85%b1%e7%84%a6%e6%98%be%e5%be%ae%e6%8b%89%e6%9b%bc%e5%85%89%e8%b0%b1%e7%a0%94%e7%a9%b6%28%e8%8b%b1%e6%96%87%29.pdf?sequence=1&isAllowed=y

The Applications of Confocal Raman Micro-Spectroscopy for study of practical electrode materials

Abstract

Similar works

Full text

Available Versions

Xiamen University Institutional Repository