Application of Electrochemical Impedance Spectroscopy in Research of Organic Coatings

doi:10.11902/1005.4537.2025.299

Journal of Chinese Society for Corrosion and protection

2026, Vol. 46

Issue (4): 945-961 DOI: 10.11902/1005.4537.2025.299

Current Issue | Archive | Adv Search

Application of Electrochemical Impedance Spectroscopy in Research of Organic Coatings

YONG Xingyue¹(

), DONG Xiaomei¹, GAO Xinhua², LI Zuoxian¹, CHEN Yanfei³, JI Haotian¹

^1.State Key Lab of Organic-Inorganic Composite, Beijing University of Chemical Technology, Beijing 100029, China
^2.China Ship Development and Design Center, Wuhan 430064, China
^3.The Sixth Military Representative Office of Air Force Ammarnent Department in Beijing, Beijing 100000, China

Cite this article:

YONG Xingyue, DONG Xiaomei, GAO Xinhua, LI Zuoxian, CHEN Yanfei, JI Haotian. Application of Electrochemical Impedance Spectroscopy in Research of Organic Coatings. Journal of Chinese Society for Corrosion and protection, 2026, 46(4): 945-961.

Download:

HTML

PDF(7749KB)
Export: BibTeX | EndNote (RIS)

Abstract

In this paper, the electrochemical impedance spectroscopy (EIS) characteristics of organic coating systems at different failure stages and their corresponding equivalent circuit models were summarized in terms of the theory related with the electrical properties of organic coatings, and a correlation system of “impedance characteristics-failure stages-equivalent circuits” was established. Secondly, based on key parameters such as coating resistance and capacitance obtained by fitting the equivalent circuit model, a relational expression between coating capacitance and the diffusion coefficient of the medium in the organic coating was alsoestablished. A method for calculating coating porosity and a formula for calculating the corrosion area induced by the diffusion of corrosive media to the coating/metal substrate interface were also proposed, enabling the quantitative evaluation of the protective performance of coatings. Meanwhile, a method of using the graphical approach to obtain impedance spectrum characteristic parameters for efficient comparison and ranking of the corrosion resistance of different organic coating systems was introduced. Combined with impedance spectrum fitting parameters, an in-depth analysis of the synergistic mechanism between radiation effect and corrosion during the failure process of organic coating systems was conducted, and an equivalence relationship model between accelerated tests and natural atmospheric exposure was also constructed. Finally, the paper discussed the precautions, limitations, and corresponding solutions for the application of EIS in the research of organic coating systems. The relevant results can provide a reference for applying EIS technology in conducting research related to organic coatings.

Key words: organic coating electrochemical impedance spectroscopy (EIS) equivalent circuit model electrochemical parameters of organic coatings

Received: 19 September 2025 32134.14.1005.4537.2025.299

ZTFLH:

TG172

Fund: National Natural Science Foundation of China(52171062)

Corresponding Authors: YONG Xingyue, E-mail: yongxy@mail.buct.edu.cn

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	YONG Xingyue
	DONG Xiaomei
	GAO Xinhua
	LI Zuoxian
	CHEN Yanfei
	JI Haotian

URL:

https://www.jcscp.org/EN/10.11902/1005.4537.2025.299 OR https://www.jcscp.org/EN/Y2026/V46/I4/945

Fig.1 Current variation of insulating materials under DC voltage and their equivalent electric circuit: (a) experimental schematic diagram, (b) equivalent electric circuit of insulating medium, (c) schematic diagram of absorption current^[21,25]

Fig.2 Typical Bode plots of coated electrodes: (a) when the coating starts to be immersed, no electrolyte diffuses into the coating, (b) after the coating is immersed, electrolyte diffuses into the coating, (c) after the coating is immersed, electrolyte diffuses to the coating/substrate interface and causes coating delamination^[26]

Fig.3 Typical Nyquist plots of coated electrodes and their equivalent electric circuits: (a) a straight line parallel to the imaginary axis and perpendicular to the real axis, showing a pure capacitive reactance, (b) a capacitive loop, (c) two capacitive loops, (d) a capacitive loop in the high-frequency region and a Warburg impedance in the low-frequency region^[26]

Fig.4 Bode plot of the coated electrode with Warburg diffusion impedance in the intermediate frequency region (a) and its corresponding equivalent electric circuit (b)^[13]

Fig.5 Schematic diagram of corrosion under organic coating (a), equivalent capacitance diagram dur-ing corrosion under organic coating (b)^[31]

Fig.6 Effect of the percentage of micro-defect areas on the impedance magnitude of the equivalent electric circuit for coated steel (assuming a total cell area of 10 cm²): (a) magnitude plot (b) phase angle plot^[37]

Fig.7 Bode plots of epoxy-coated steel in artificial seawater, where the solid lines are fitted by the equivalent electric circuit: (a) magnitude plot, (b) phase angle plot^[37]

Fig.8 Bode plots of aluminum alloy with chromate pretreatment and chromate primer coating during 162 d of exposure in a 5%NaCl solution (sample area: 5.5 cm²): (a) magnitude plot; (b) phase angle plot^[38]

Fig.9 Effect of exposure time on (a) breakpoint frequency f_l or f_h, and (b) OCP and |Z|_0.01 values^[38]

Fig.10 Variation of (a) coating resistance and (b) coating capacitance with Theta (phase angle at 10 KHz) for zinc phosphate and zinc chromate pigmented epoxy coatings during 28 d of immersion in a 3.5%NaCl solution^[39]

Fig.11 Typical Bode plots: used as training for high, intermediate, and poor coating quality^[39]

Fig.12 EIS of coated ion-plated Al-Ti alloy samples after accelerated tests in a simulated plateau atmospheric environment: (a) after UVA irradiation; (b) after immersion/drying tests; (c) after the interactive effect of UVA irradiation and immersion/drying cycle tests^[43]

Table 1 values of CI_uv, CI_c, CI_{uv, c} and ΔCI for the coated ion-plated Al-Ti alloy samples in a simulated plateau atmospheric environment^[43]

Fig.13 EIS of coated Al-alloys after (a) natural exposure in Hainan, China, and (b) accelerated tests in a simulated marine atmospheric environment^[22]

Fig.14 Variation of ln (R_c + R_ct) with natural exposure years or accelerated test cycles: (a) natural exposure in Hainan, (b) accelerated tests in a simulated marine atmospheric environment^[22]

Fig.15 Equivalent electric circuit of the coated electrode with two time constants

Fig.16 Region of the coating is separated into components that model the diffusion-affected zone and the pristine coating^[32]

Fig.17 Electrical resistivity and relative dielectric constants for the diffusion-affected zone are modeled in three ways: (a) first as percolation paths which act as channels to deliver water to the interface and advance the diffusion-affected zone, (b) second model assumes a Maxwell-type two-phase system where water fills the voids inside the coating, and coating stresses valve the polymer between inclusions to result in water movement, (c) third model combines inclusions, holding most of the water, with a few channels that connect the water inclusions^[32]

Fig.18 EIS Bode modulus spectra as predicted by model calculations when the interface resistance is set to 0. (a) shows results predicted by “Maxwell” type averaging of both relative dielectric constant and resistivity. Spectra (b-d) show the calculated resistivity of inclusions combined with a few percolation paths, which reduce the resistance to various levels, listed in figure as R; the small impact on dielectric constant due to a small number of percolation paths is neglected^[32]

Fig.19 EIS Bode phase angle spectra for the same conditions as given in Fig.18. Spectrum (a) gives results predicted by “Maxwell” type averaging of both relative dielectric constant and resistivity. Spectra (b-d) show the combined effect of inclusions with a few percolation paths, which reduce the resistance to various levels, listed in figure as R; the small impact on dielectric constant due to a small number of percolation paths is neglected^[32]

[1]	Weldon D G, translated by Yang Z, Yong X Y. Failure analysis of paints and coatings [M]. Beijing: Chemical Industry Press, 2011: 1
	德怀特 ⋅ G ⋅ 韦尔登著, 杨智, 雍兴跃译. 涂层失效分析 [M]. 北京: 化学工业出版社, 2011: 1
[2]	Yu F, Wang X, Zhang Z. Research progress of nanofillers for epoxy anti-corrosion coatings [J]. J. Chin. Soc. Corros. Prot., 2023, 43: 220
	于芳, 王翔, 张昭. 纳米填料在环氧防腐涂层中的应用研究进展 [J]. 中国腐蚀与防护学报, 2023, 43: 220
[3]	Gerhardus H K, Michiel P H B, Neil G T, et al. Corrosion costs and preventive strategies in the United States, NO. FHWA-RD-01-156, Materials Performance, 2002
[4]	Souto R M, Liorente M L, Fernández-Mérida L. Accelerated tests for the evaluation of the corrosion performance of coil-coated steel sheet: EIS under cathodic polarisation [J]. Prog. Org. Coat., 2005, 53: 71 doi: 10.1016/j.porgcoat.2005.01.009
[5]	Zhang W, Wang J, Zhao Z Y, et al. EIS study on the deterioration process of organic coatings under immersion and cyclic wet-dry conditions [J]. J. Chin. Soc. Corros. Prot., 2011, 31: 329
	张伟, 王佳, 赵增元等. 电化学阻抗谱对比研究连续浸泡和干湿循环条件下有机涂层的劣化过程 [J]. 中国腐蚀与防护学报, 2011, 31: 329
[6]	Bedoya F E, Bermúdez Á, Castaño J G, et al. Electrochemical impedance study for modeling the anticorrosive performance of coatings based on accelerated tests and outdoor exposures [J]. J. Coat. Technol. Res., 2016, 13: 895 doi: 10.1007/s11998-016-9803-7
[7]	Philip M, Al-Azzawi F. Effects of natural and artificial weathering on the physical properties of recycled poly (ethylene terephthalate) [J]. J. Polym. Environ., 2018, 26: 3139 doi: 10.1007/s10924-018-1191-x
[8]	Pérez C, Collazo A, Izquierdo M, et al. Characterisation of the barrier properties of different paint systems: Part II. Non-ideal diffusion and water uptake kinetics [J]. Prog. Org. Coat., 1999, 37: 169 doi: 10.1016/S0300-9440(99)00073-9
[9]	Bedoya-Lora F E, Echeverría F, Calderón J A. Effectiveness of non-fickian diffusion model on the water uptake determination of different organic coatings [J]. Prog. Org. Coat., 2019, 136: 105206
[10]	Chen X, Wen S F, Feng T, et al. Investigating an effective model to estimate the water diffusion coefficient of a hybrid polymer-oxide coating [J]. Prog. Org. Coat., 2020, 141: 105548
[11]	Hu J M, Zhang J Q, Xie D M, et al. Water transport in organic coatings (Ⅱ) A complicated actual trend [J]. J. Chin. Soc. Corros. Prot., 2002, 22: 371
	胡吉明, 张鉴清, 谢德明等. 水在有机涂层中的传输II复杂的实际传输过程 [J]. 中国腐蚀与防护学报, 2002, 22: 371
[12]	Brasher D M, Kingsbury A H. Electrical measurements in the study of immersed paint coatings on metal. I. Comparison between capacitance and gravimetric methods of estimating water-uptake [J]. J. Appl. Chem., 1954, 4: 62 doi: 10.1002/jctb.v4:2.n
[13]	Cao C N, Zhang J Q. An Introduction to Electrochemical Impedance Spectroscopy [M]. Beijing: Science Press, 2002: 75
	曹楚南, 张鉴清. 电化学阻抗谱导论 [M]. 北京: 科学出版社, 2002: 75
[14]	Lvovich V F. Impedance Spectroscopy: Applications to Electrochemical and Dielectric Phenomena [M]. Hoboken: John Wiley & Sons, Inc., 2012: 281
[15]	Akbarinezhad E, Rezaei F, Neshati J. Evaluation of a high resistance paint coating with EIS measurements: Effect of high AC perturbations [J]. Prog. Org. Coat., 2008, 61: 45 doi: 10.1016/j.porgcoat.2007.09.004
[16]	SSekine I, Yuasa M, Hirose N, et al. Degradation evaluation of corrosion protective coatings by electrochemical, physicochemical and physical measurements [J]. Prog. Org. Coat., 2002, 45: 1 doi: 10.1016/S0300-9440(02)00113-3
[17]	Mills D, Jamali S, Tobiszewski M T. Developing electrochemical measurements in order to assess anti-corrosive coatings more effectively [J]. Prog. Org. Coat., 2012, 74: 385 doi: 10.1016/j.porgcoat.2011.11.002
[18]	Darowicki K, Szociński M, Zieliński A. Assessment of organic coating degradation via local impedance imaging [J]. Electrochim. Acta, 2010, 55: 3741 doi: 10.1016/j.electacta.2010.01.081
[19]	Margarit-Mattos I C P. EIS and Organic Coatings Performance: Revisiting Some Key Points. Electrochimica Acta, 2020, 354: 136725 doi: 10.1016/j.electacta.2020.136725
[20]	Taylor R, Contu F. A Short Course on Electrochemical Impedance Spectroscopy Theory, Applications and Laboratory Instruction [M]. Houston: The Materials Research Company, 2013: 77277
[21]	Stone G C, Culbert I, Boulter E A, et al. Electrical Insulation for Rotating Machines: Design, Evaluation, Aging, Testing, and Repair [M]. 2nd ed. Hoboken: Wiley, 2014
[22]	Yong X Y, Ji H T, Chen Z N, et al. Comparison between accelerated tests and natural exposures for organic coating protective systems based on EIS parameters [J]. J. Electrochem. Soc., 2021, 168: 121506 doi: 10.1149/1945-7111/ac3ff3
[23]	Yong X Y, Hu X Y, Jiang L, et al. Damage assessment of the corrosion-resistant performances for organic coating systems after accelerated tests using analytic hierarchy process [J]. Eng. Failure Anal., 2018, 93: 1 doi: 10.1016/j.engfailanal.2018.06.015
[24]	Cao C N. The Principle of Corrosion Electrochemistry (2nd ed) [M]. Beijing: Chemical Industry Press, 2004
	曹楚南. 腐蚀电化学原理 (2版) [M]. 北京: 化学工业出版社, 2004
[25]	Virtual Simulation Experiment System for Transformer High-Voltage Discharge and Insulation Testing https://www.ilab-x.com/details/page?id=5103&isView=true%20#1001
	李明伟. 变压器高压放电与绝缘测试虚拟仿真实验系统，实验介绍/实验原理 https://www.ilab-x.com/details/page?id=5103&isView=true%20#1001
[26]	Caldona E B, Smith Jr D W, Wipf D O. Surface electroanalytical approaches to organic polymeric coatings [J]. Polym. Int., 2021, 70: 927 doi: 10.1002/pi.6126
[27]	Armstrong R D, Wright D. Polymer protective coatings—the distinction between coating porosity and the wetted metal area [J]. Electrochim. Acta, 1993, 38: 1799 doi: 10.1016/0013-4686(93)80301-F
[28]	Krzak M, Tabor Z, Nowak P, et al. Water diffusion in polymer coatings containing water-trapping particles. Part 2. Experimental verification of the mathematical model [J]. Prog. Org. Coat., 2012, 75: 207 doi: 10.1016/j.porgcoat.2012.05.008
[29]	Van Westing E P M, Ferrari G M, De Wit J H W. The determination of coating performance with impedance measurements—II. Water uptake of coatings [J]. Corros. Sci., 1994, 36: 957 doi: 10.1016/0010-938X(94)90197-X
[30]	Van Westing E P M, Ferrari G M, De Wit J H W. The determination of coating performance with impedance measurements—III. In situ determination of loss of adhesion [J]. Corros. Sci., 1994, 36: 979 doi: 10.1016/0010-938X(94)90198-8
[31]	Scully J R. Electrochemical impedance of organic-coated steel: Correlation of impedance parameters with long-term coating deterioration [J]. J. Electrochem. Soc., 1989, 136: 979 doi: 10.1149/1.2096897
[32]	Hinderliter B R, Croll S G, Tallman D E, et al. Interpretation of EIS data from accelerated exposure of coated metals based on modeling of coating physical properties [J]. Electrochim. Acta, 2006, 51: 4505 doi: 10.1016/j.electacta.2005.12.047
[33]	Bierwagen G, Tallman D, Li J P, et al. EIS studies of coated metals in accelerated exposure [J]. Prog. Org. Coat., 2003, 46: 149 doi: 10.1016/S0300-9440(02)00222-9
[34]	Cristoforetti A, Rossi S, Deflorian F, et al. On the limits of the EIS low-frequency impedance modulus as a tool to describe the protection properties of organic coatings exposed to accelerated aging tests [J]. Coatings, 2023, 13: 598 doi: 10.3390/coatings13030598
[35]	Hirayama R, Haruyama S. Electrochemical impedance for degraded coated steel having pores [J]. Corrosion, 1991, 47: 952 doi: 10.5006/1.3585208
[36]	Scully J R, Hensley S T. Lifetime prediction for organic coatings on steel and a magnesium alloy using electrochemical impedance methods [J]. Corrosion, 1994, 50: 705 doi: 10.5006/1.3293547
[37]	Hack H P, Scully J R. Defect area determination of organic coated steels in seawater using the breakpoint frequency method [J]. J. Electrochem. Soc., 1991, 138: 33 doi: 10.1149/1.2085574
[38]	Feng Z C, Frankel G S. Evaluation of coated al alloy using the breakpoint frequency method [J]. Electrochim. Acta, 2016, 187: 605 doi: 10.1016/j.electacta.2015.11.114
[39]	Mahdavian M, Attar M M. Another approach in analysis of paint coatings with EIS measurement: Phase angle at high frequencies [J]. Corros. Sci., 2006, 48: 4152 doi: 10.1016/j.corsci.2006.03.012
[40]	Akbarinezhad E, Bahremandi M, Faridi H R, et al. Another approach for ranking and evaluating organic paint coatings via electrochemical impedance spectroscopy [J]. Corros. Sci., 2009, 51: 356 doi: 10.1016/j.corsci.2008.10.029
[41]	Touzain S. Some comments on the use of the EIS phase angle to evaluate organic coating degradation [J]. Electrochim. Acta, 2010, 55: 6190 doi: 10.1016/j.electacta.2009.09.045
[42]	Nguyen A S, Musiani M, Orazem M E, et al. Impedance analysis of the distributed resistivity of coatings in dry and wet conditions [J]. Electrochim Acta, 2015, 179: 452 doi: 10.1016/j.electacta.2015.02.109
[43]	Yong X Y, Chen Z N, Ruan X, et al. Quantitative determination of the synergistic effects between UV irradiation and corrosion using the coating impedance index [J]. Prog. Org. Coat., 2019, 136: 105230
[44]	Guseva O, Brunner S, Richner P. Service life prediction for aircraft coatings [J]. Polym. Degrad. Stab., 2003, 82: 1 doi: 10.1016/S0141-3910(03)00124-1

[1]	LIU Suyun, LI Wanting, ZHOU Runqi, LIU Rui, DONG Zhijun, LIU Li, WANG Fuhui. Thermal Conductivity and Corrosion Resistance of Epoxy Composite Coatings with Polydopamine Modified Mult-scale Boron Nitrides[J]. 中国腐蚀与防护学报, 2026, 46(3): 767-776.
[2]	GUO Yujie, LI Yanhui, XIA Da-Hai, HU Wenbin. Data Analysis and Physical Model of Electrochemical Impedance Spectroscopy for Corrosion Systems: Progresses and Challenges[J]. 中国腐蚀与防护学报, 2025, 45(5): 1143-1160.
[3]	LI Jie, MENG Fandi, SUN Xuesi, LI Jiani, CHEN Sihan, LI Zelan, CHI Jianning, QI Haixia, WANG Fuhui, LIU Li. Lifetime Prediction for Organic Coatings via Feature Integration of Multi-Scale Images[J]. 中国腐蚀与防护学报, 2025, 45(5): 1205-1218.
[4]	CHEN Lijuan, CHAO Liuwei, ZHAO Jingmao. Preparation of CeO₂@Zr-MOF Composites and Their Effect on Corrosion Protectiveness of Epoxy Coatings on Galvanized Steel Plate[J]. 中国腐蚀与防护学报, 2025, 45(3): 664-674.
[5]	FU Jiangyue, GUO Jianxi, YANG Yange, LENG Zhe, WANG Wen. Erosion-corrosion Behavior of a High Strength Low Alloy Steel in Flowing 3.5%NaCl Solution[J]. 中国腐蚀与防护学报, 2024, 44(3): 585-600.
[6]	LI Zhuoxuan, CAO Yanhui, LI Chongjie, LI Hui, ZHANG Xiaoming, YONG Xingyue. Relationship Between Corrosion Failure Degree of Organic Coatings and Mechanical Properties for Dissimilar Metal Assamblies[J]. 中国腐蚀与防护学报, 2024, 44(3): 679-690.
[7]	MENG Fandi, GAO Haodong, LIU Li, CUI Yu, LIU Rui, WANG Fuhui. Preparation and Anticorrosive Performance of a Basalt Organic Coating for Deep Sea Coupled Pressure-fluid Environment[J]. 中国腐蚀与防护学报, 2023, 43(4): 704-712.
[8]	WANG Tong, WANG Wei. Distribution of Relaxation Time of Polydimethylsiloxane Coatings During Self-healing Process[J]. 中国腐蚀与防护学报, 2023, 43(2): 337-344.
[9]	CHEN Yifan, MENG Fandi, QU Youyi, FANG Zhiqing, LIU Li, WANG Fuhui. One-step Synthesis of Superhydrophobic Polyaniline Capsules and Its Effect on Corrosion Resistance of Organic Coatings[J]. 中国腐蚀与防护学报, 2023, 43(2): 345-351.
[10]	LUAN Hao, MENG Fandi, LIU Li, CUI Yu, LIU Rui, ZHENG Hongpeng, WANG Fuhui. Preparation and Anticorrosion Performance of M-phenylenediamine-graphene Oxide/Organic Coating[J]. 中国腐蚀与防护学报, 2021, 41(2): 161-168.
[11]	CAO Jingyi, WANG Zhiqiao, LI Liang, MENG Fandi, LIU Li, WANG Fuhui. Failure Mechanism of Organic Coating with Modified Graphene Under Simulated Deep-sea Alternating Hydrostatic Pressure[J]. 中国腐蚀与防护学报, 2020, 40(2): 139-145.
[12]	Qi GUI, Dajiang ZHENG, Guangling SONG. Electrochemically Accelerated Evaluation of Protectiveness for an Alkyd Varnish Coating[J]. 中国腐蚀与防护学报, 2018, 38(3): 274-282.
[13]	Fandi MENG, Li LIU, Ying LI, Fuhui WANG. *Embedded Microelectrode for In situ* Electrochemical Impedance Spectroscopy Measurement of Organic Coating Under Marine Alternating Hydrostatic Pressure**[J]. 中国腐蚀与防护学报, 2017, 37(6): 561-566.
[14]	Jia WANG, Mengyang JIA, Zhaohui YANG, Bing HAN. On Completeness of EIS Equivalent Circuit Analysis for Electrochemical Corrosion Process[J]. 中国腐蚀与防护学报, 2017, 37(6): 479-486.
[15]	LIU Shuyun, WANG Shuaixing, DU Nan, WANG Liqiang, XIAO Jinhua. Electrochemical Behavior of X80 Pipeline Steel in Simulated Red Soil Solutions with Different pH[J]. 中国腐蚀与防护学报, 2015, 35(1): 21-26.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed