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Electrochemical Methods

phone: 02/9714733; 02/979 2765, e-mail:

Research area

The research focus of the Department is on the development of conventional and advanced electrochemical methods such as: impedance, dielectric and coulometric spectroscopies, non-stationary and differential analysis, spectral transforms and image diagnostics. The Department’s activities include also testing and qualification of batteries and fuel cells, incl. investigation, modeling and diagnostics of high temperature solid oxide fuel cells (SOFC), as well as diagnostics of large industrial batteries. Intelligent hydrogen and hybrid systems for energy storage and transport applications are developed.


  • Gergana Raikova, Assoc. Prof., PhD (active head)
  • Daria Vladikova, Professor, DSc 
  • Blagoy Burdin, Assoc. Prof., PhD
  • Milena Krapchanska, Res. Assoc., PhD
  • Emiliya Mladenova, Res. Assoc., PhD
  • Miglena Slavova, Res. Assoc., PhD
  • Ivaylo Genov, Res. Assist., PhD
  • Elena Mihaylova, Res. Assist., PhD
  • Dimitar Boychev, Res. Assist.
Access Impedance

European internet centre for impedance spectroscopy

Access Impedance - the web site of the European Internet Centre for Impedance Spectroscopy (EICIS) - a free access to a new impedance world without geographical and time barriers.

Projects (2011 - 2021)

Publications (2011 - 2019)

  1. К. Хаджииванов, Е. Славчева, Д. Владикова, Д. Панайотов: Българската научна общност в борбата с климатичните промени. Наука, (2019) №2, 29-32,  (in Bulgarian)
  2. D. Vladikova, M. Pandev, G. Raikova, FUEL CELLS AND HYDROGEN: Identification of Deployment Legal Rules and Administrative process, as well as Barriers and approaches for their Removal. POLICY PAPERS, published by: IEES-BAS, Sofia, 2019, ISBN: 978-954-92483-5-7 (in Bulgarian).
  3. Ivanova, G., Stoyanova, A., Mladenov, M., Raicheff, R., Kovacheva, D. Effect of the concentration of MnO2 in the composite electrode and the electrolyte on the electrochemical properties of a hybrid supercapacitor. Bulgarian Chemical Communications, 50 Special Issue A, Bulgarian Academy of Sciences, 2018, ISSN:0324-1130, 146-152.
  4. Stoynov, Z., Vladikova, D., Abrashev, B., Slavova, M., Burdin, B., Mihaylova-Dimitrova, E., Colmenares, L., Mainar, A., Blazquez, J.. Screening impedance analysis of Zn-air cells. Bulgarian Chemical Communication, 50, Special Issue A, 2018, ISSN:0324-1130, 189-194.
  5. Stoynov, Z., Vladikova, D., Burdin, B., Laurencin, J., Montinaro, D., Raikova, G., Schiller, G., Szabo, P. Differential analysis of SOFC current-voltage characteristcs. Applied Energy, 288, Elsevier Ltd., 2018, ISSN:ISSN: 0306-2619,, 1584-1590.
  6. Stoynov. Z., Vladikova, D., Burdin, B.. Differential Resistance Analysis – Current Achievements and Applications. Bulgarian Chemical Communications, Volume 50, Special Issue D, 2018, 21-30., 50, Special Issue D, 2018, 21-30.
  7. Vladikova, D.. Professor Zdravko Stoynov - The Scientist Who Created New Horizons (16.05.1936 – 09.09.2017). Bulgarian Chemical Communications, 50, Special Issue D, 2018, 7-20.
  8. Z. Stoynov, D. Vladikova, B. Burdin, A. Thorel, A. Chesnaud, P. Piccardo, M. Slavova, R. Spotorno. Electrochemical Testing of an Innovative Dual Membrane Fuel Cell Design in Reversible Mode. Bulgarian Chemical Communications, 50, Special Issue A, 2018, ISSN: 0324-1130, 139-145.
  9. Gabrovska M. V., Nikolova D. A., Mladenova E. A., Vladikova D. E., Rakovsky S. K., Stoynov Z.B.. Ni incorporation in pSOFC anode ceramic matrix: Part II. Wet chemical reduction in an anhydrous medium. Bulgarian Chemical Communications, Special Issue A, Volume 50, 2018, 119-126.
  10. R. Tomova, S. Asenova, B. Atanasova, K. Tzoneva, M. Nikolova, M. Slavova, R. Hadjiolova. MACRO - AND MICROELEMENTS AND THEIR PHYSIOLOGICAL IMPORTANCE FOR THE BONE MINERAL DENSITY. Knowledge international journal, 26, 4, Institute for knowledge management - Skopje, 2018, 1211-1216.
  11. Abrashev, B., Spassov, T., Pandev, M., Vassilev, S., Popov, A.. Hydrogen sorption and electrochemical properties of Ti-Fe based alloys synthesized by mechanical alloying. Bulgarian Chemical Communications, 49, C, 2017.
  12. Levi, D., Stoynov, Z., Vladikova, D.. Application of permittivity spectroscopy for screening of motor oils lubricating properties. Bulgarian Chemical Communications, 49, Special Issue C, Institute of Chemical Engineering-BAS, 2017.
  13. Mladenova E., Burdin B., Milchev A.. Electrochemical nucleation and growth of three-dimensional clusters: the case of multi-step ion discharge-II. Journal of Solid State Electrochemistry, 21, 6, 2017.
  14. Mladenova E., Milchev A.. Electrochemical nucleation and growth of three-dimensional clusters: the case of multi-step ions discharge–I. Journal of The Electrochemical Society, 21, 6, 2017.
  15. Pandev, M., Lucchese, P, Mansilla, C., Le Duigou, A., Abrashev. B., Vladikova, D.. HYDROGEN ECONOMY: THE FUTURE FOR A SUSTAINABLE AND GREEN SOCIETY. Bulgarian Chemical Communications, 49, C, 2017.
  16. Raikova, G., Krezhov, K., Genov, I., Thorel, A., Chesnaud, A., Malakova, T., Vladikova, D., Stoynov, Z.. Structural and electrochemical characterization of yttrium doped barium cerate BaCe0.85Y0.15O3-α for applications in solid oxide fuel cells. Bulgarian Chemical Communications, 49, Special Issue C, Institute of Chemical Engineering-BAS, 2017.
  17. Stoynov, Z., Obretenov, V.. Academician Evgeni Budevski. Bulgarian Chemical Communications, 49, Special Issue C, Institute of Chemical Engineering-BAS, 2017.
  18. Vladikova, D.. Zdravko Stoynov- the scientist who turns the curiosity into multidisciplinariry. Bulgarian Chemical Communications, 49, Special Issue C, Institute of Chemical Engineering-BAS, 2017.
  19. M. V. Gabrovska, D. A. Nikolova, E. A. Mladenova, D. E. Vladikova, S. K. Rakovsky, Z. Stoynov. Ni incorporation in pSOFC anode ceramic matrix: Part I. Wet chemical reduction in an aqueous medium. 49, Special Issue C, Bulgarian Chemical Communications, 2017, 171-178. 
  20. Slavova, M, Georgieva-Nikolova, R, Hristov, H, Nikolova, M. Covalent immobilization of rabbit-antiaflatoxin-antibodies onto the poly-acrylamideacrylonitrile as well as hybrid material UREASIL and developing an optical immunosensor. Acta Scientifica Naturalis, 4, 1, DE GRUYTER OPEN, 2017, ISSN:2367-5144, 52-56.
  21. Slavova, M. ЕКОЛОГИЧЕН ТРАНСПОРТ – ВОДОРОДНИ ПРЕВОЗНИ СРЕДСТВА. Научно списание ”Механика, Транспорт, Комуникации”, 1 5, 3, фондация Отворено общество, 2017, ISSN:2367 - 6620, IX - 13-IX - 18 
  22. Stoynov Z., Vladikova D., Burdin B., Laurencin J., Montinaro D., Nakajo Ar., Piccardo P., Thorel Al., Hubert M., Spotorno R., Chesnaud A.. Differential Resistance Analysis – a New Tool for Evaluation of Solid Oxide Fuel Cells Degradation. MRS Advances, Cambridge University Press, 2017, DOI:10.1557/adv.2017.592.
  23. Vladikova D., Stoynov Z., Burdin B., Raikova, G., Krapchanska, M., Thorel, A., Chesnaut, A.. Reversibility in an Innovative Dual Membrane Fuel Cell Design. Machines, Technologies, Materials, 4, Scientific-Technical Union of Mechanical Engineering, 2017, 190-193.
  24. Piccardo, P., Spotorno, R., Ouweltjes, J.P., Stoynov, Z., Vladikova, D.. Parametrical coordinates and microsamples to investigate real SOFCs in operating stacks. ECS Meeting Abstracts, 78, 1, The Electrochemical Society, 2017, ISSN:2151-2043, 2087-2098.
  25. Akay, S., Esat, B, Vladikova, D., Genov, I., Mladenova, E.,  A Novel Proton Conducting Polymer Functionalized with 1-Hydroxy-Benzimidazole-3-oxide. International Journal of Hydrogen Energy, Volume 41, Issue 28, Elsevier Ltd., 2016, , 12101-1210.
  26. Gateva, PA, Angelova, VT, Georgieva-Nikolova, RT, Veselinov, TR, Nankova, VH, Nikolova, MM, Hadjiolova, RK, Slavova, MP., Synthetic cannabimimetics detected in smoking blends on the Bulgarian territory–toxicological significance. BULGARIAN CHEMICAL COMMUNICATIONS, 48, 3, BULGARIAN ACADEMY of SCIENCE, 2016, 461-468.
  27. Koleva, O., Kochnitcharova, D., Mladenova, E., Lefterova, E., Petkova, T., Vladikova, D., Structure-conductivity correlation in (TiO2)5(V2O5)70(P2O5)25 glass for low-temperature SOFCs. Bulgarian Chemical Communications, 48, Special Issue B, BULGARIAN ACAD SCIENCE, 2016.
  28. Krezhov, K., Vladikova, D., Raikova, G., Genov, I., Malakova, T., Dimitrov, D., Svab, E., Fabian, M., Structure Study of BaCe0.85Y0.15O3-Δ (BCY15) as Solid Oxide Fuel Cell Materal. AIP Conference Proceedings, 1722, AIP Publishing LLC, 2016.
  29. Mladenova, E., Stoynov, Z., Vladikova, D., Comparative studies of polarizable dielectric fluids in yttrium-doped barium cerate by Permittivity Spectroscopy. Bulgarian Chemical Communications, 48, Special Issue B, 2016, 39-42.
  30. Veleva, S., Stoyanov, L., Stoyanova, A., Girginov, Ch., Mladenov, M., Kovacheva, D., Raicheff R.. A hybrid supercapacitor: activated carbon/LiBF4/activated carbon-biogenic Fe2O3 composite. BULGARIAN CHEMICAL COMMUNICATIONS, 48, 4, Bulgarian Academy of Sciences, 2016,  758-762.  
  31. Raicheff, R., Mladenov, M., Stoyanov, L., Boshkov, N., Bachvarov V., Novel current collector and active mass carrier of the zinc electrode for alkaline nickel-zinc batteries. BULGARIAN CHEMICAL COMMUNICATIONS, 48, 1, Bulgarian Academy of Sciences, 2016, 61-65.
  32. Milchev A., Nucleation phenomena in electrochemical systems: thermodynamic., Journal Chem. Text., ChemTexts (2016) 2: 4.
  33. Vladikova, D.E., Stoynov, Z.B., Wuillemin, Z., Montinaro, D., Piccardo, P., Genov, I., Rolland, M., Impedance Studies of the Reduction Process in NiO-YSZ SOFC Anodes. ECS Transactions (ECST), 68(1)2015, pp.1161 - 1168
  34. Vladikova, D., Stoynov, Z., Chesnaud, A., Thorel, A., Viviani, M., Barbucci, A., Nicolella, A., Bertei, A., Raikova, G., Carpanese, P., Krapchanska, M., Reversibility in Monolithic Dual Membrane Fuel Cell. Bulgarian Chemical Communications, 47(2) 2015, pp. 519 - 525.
  35. Stoyanova-Ivanova, A., Terzieva, S., Ivanova, G., Mladenov, M., Kovacheva, D., Raicheff, R., Georgieva, S., Blagoev, V., Zaleski, A., Mikli, V., The use of high -temperature superconducting cuprate as a dopant to the negative electrode in Ni-Zn batteries. Bulgarian Chemical Communications, 47, 1, 2015, ISSN:0324-1130, 221 - 228. ISI IF:0.349
  36. Stoyanov, L., Terzieva, S., Stoyanova, A., Stoyanova-Ivanova, A., Mladenov, M., Kovacheva, D., Raicheff, R., Superconducting BSCCO ceramics as additive to the zinc electrodе mass in rechargeable nickel-zinc batteries. Journal of Progressive Research in Chemistry [JPRC], 2, 2, 2015, ISSN:ISSN 2454-3136, 83 - 91. ISI IF:0.791
  37. Slavova, M.P., Zamfirova, G.I., Boev, V.I., Gaydarov VT, Yotova, L.K., Gomes, M.J.M., Silva, C.J.R., Controlled aggregation of gold nanoparticles in a di - ureasil m atrix . Optical and micro in dentation investigation. Bulgarian Chemical Communications, 47, 2, Journal of the Chemical Institutes of the Bulgarian Academy of Sciences and of the Union of Chemists in Bulgaria, 2015, ISSN:0324-1130, 699 - 705. ISI IF:0.349
  38. Ionascu, A.M., Raikova, G., Mladenova, E., Mercioniu, I., Electrical Conductivity Studies of Scandia Doped Ceria. Digest Journal of Nanomaterials and Biostructures, 10, 4, Virtual Institute of Physics operated by Virtual Company of Physics, 2015, ISSN:1842 - 3582, 1275 - 1280. ISI IF:0.945
  39. Girginov, Ch, Stoyanov, L, Kozhukarov, S, Stoyanova, A, Mladenov, M, Raicheff, R., Study on adsorption properties of carbon electrode materials for electrochemical supercapacitors. Сб. на научни трудове на Русенския университет „Ангел Кънчев”, 54, 10.1, 2015, ISSN:1311-3321, 89 - 95
  40. Gergova, R.T., Slavova, M.P., Boev, V.I., Mourdjeva, M.S., Yotova, L.K., Georgieva-Nikolova, R.T., Comparative investigation the feasibility of bacterial biofilms formation on the surface of hybrid material UREASIL. Bulgarian Chemical Communications, 47, 2, Journal of the Chemical Institutes of the Bulgarian Academy of Sciences and of the Union of Chemists in Bulgaria, 2015, ISSN:0324-1130, 706 - 713. ISI IF:0.349
  41. Geagea, M., Genov, I., Stoynov, Z., Vladikova, D., Chesnaud, A., Thorel, A., Permeability of Gases in the Anode of an Anode Supported SOFC. ECS Transactions (ECST), 68, 1, 2015, ISSN:1938-6737, DOI:doi: 10.1149/06801.1185ecst, 1185 - 1192
  42. G. Ivanova, L. Stoyanov, S. Terzieva, A. Stoynova-Ivanova, M. Mladenov, D. Kovacheva, R. Raicheff, Stability of superconducting phase BSCCO ceramics in strong alkaline Solution, Nanoscience and Nanotechnology 14, Eds. Е. Balabanova, E. Mileva, Publ. BPC ltd., Sofia (2014) p. 33-35
  43. Sv. Veleva, R. Angelova, L. Stoaynov, V. Grudeva, D. Kovacheva, M. Mladenov, R. Raicheff, Biogenic iron oxide-based nanocopmposite electrodes for hybrid battery supercapacitor systems, Nanoscience and Nanotechnology 14, Eds. Е. Balabanova, E. Milev, Publ. BPC ltd., Sofia (2014) pp. 50-52.
  44. D. Vladikova, Z. Stoynov, A. Chesnaud, A. Thorel, M. Vivianu, A. Barbucci, G. Raikova, P. Carpanese, M. Krapchanska, E. Mladenova, Application of Yttrium doped Barium Cerate for Improvement of the Dual Membrane SOFC Design, International Journal of Hydrogen Energy (2014), 39(36) 21561-21568.
  45. Z. Stoynov, E. Mladenova, D. Levi, D. Vladikova, Permittivity Spectroscopy - an insight into materials properties, Acta Chimica Slovenica, 61 (2) (2014) 255-262
  46. M. Krapchanska, D. Vladikova, Z. Stoynov, A. Chesnuad, A. Thorel, G. Raikova, E. Mladenova, I. Genov, Impedance Studies of Porous Electrolyte with Mixed Ion Conductivity, Bulg. Chem. Communic, 45/Special Issue A (2013) 135-139
  47. M. Markova-Velichkova, V. Tumbalev, L. Stoyanov, S. Veleva, D. Nihtiyanova, M.Mladenov, R. Raicheff, D. Kovacheva, “XRD and TEM characterisation of the morphology of ZnO powders prepared by different methods” (2013) Bulg. Chem. Communic., 45(4), 427-433.
  48. Mladenov. M., Alexandrova. K., Petrov. N.V., Tsyntsarski. B., Kovacheva. D., Saliyski. N., Raicheff. R., “Synthesis and electrochemical properties of activated carbons and Li4Ti5O12 as electrode materials for supercapacitors” (2013) J. Solid State Electrochem. 17(8), 2101-2108.
  49. E. Mladenova, D. Vladikova, Z. Stoynov, A. Chesnaud, A. Thorel, M. Krapchanska, “Gases Permeability Study in Dual Membrane Fuel Cell”, (2013) Bulgarian Chemical Communications 45(3), 366-370.
  50. Massimo Viviani, Alain Sylvain Thorel, Antonio Barbucci, Daria Vladikova, Anthony Chesnaud, Ivaylo Genov, Gergana Raikova, Elisa Mercadelli, Paolo Piccardo, Maria Paola Carpanese, Zdravko Stoynov, Sabrina Presto, and Alessandra Sanson, “Innovative Dual Membrane Architecture for Reversible Fuel Cells” (2013) ECS Trans., 57(1), 3143-3149.
  51. A.S. Thorel, J. Abreu, S.A. Ansar, A. Barbucci, T. Brylewski, A. Chesnaud, Z. Ilhan, P. Piccardo, J. Prazuch, S. Presto, K. Przybylski, D. Soysal, Z. Stoynov, M. Viviani, D. Vladikova, Proof of Concept for the Dual Membrane Cell, I. Fabrication and Electrochemical Testing of First Prototypes, (2013) J. Electrochem. Soc. 160(4) pp. F360-F366; doi:10.1149/2.051304jes
  52. Stanislav S. Slavov, Milena Z. Krapchanska, Elena P. Kashchieva, Svetlin B. Parvanov, Yanko B. Dimitriev, ”Dielectric properties of bismuth titanate ceramics containing SiO2 and Nd2O3 as additives” (2012) Processing and Application of Ceramics 6(3) pp.117-122.
  53. D. Vladikova, Z. Stoynov, G. Raikova, M. Krapchanska, A. Thorel, A. Chesnaud, “Dual membrane fuel cell – impedance approach for proof of concept”, (2012) Bulgarian Chemical Communications, 44(4), pp.364-370.
  54. G. Raikova, M. Krapchanska, I. Genov, G. Caboche, L. Combemale, A. Thorel, A. Chesnaud, D. Vladikova, Z. Stoynov, “Impedance Investigation of BaCe0.85Y0.15O3-δ Properties for Hydrogen Conductor in Fuel Cells”, (2012) Bulgarian Chemical Communications, 44(4), pp.389-394.
  55. A.M. Ionascu, G. Raikova, E. Mladenova, I. Mercioniu, “Electrochemical analysis of solid oxide electrolytes for intermediate temperature fuel cell”, (2012) Bulgarian Chemical Communications, 44(4), pp.395-398.
  56. Massimo Viviani, Giovanna Canu, Maria Paola Carpanese, Antonio Barbucci, Alessandra Sanson, Elisa Mercadelli, Cristiano Nicolella, Daria Vladikova, Zdravko Stoynov, Anthony Chesnaud, Alain Thorel, Zeynep Ilhan, Sayed-Asif Ansar, “Dual Cells with Mixed Protonic-Anionic Conductivity for Reversible SOFC/SOEC Operation” Fuel Cells 2012 Science & Technology – A Grove Fuel Cell Event, Energy Procedia, Vol. 28, 2012, pp. 182-189.
  57. Stoynov, Z.B., Vladikova, D.E., Mladenova, E.A., “Gigantic enhancement of the dielectric permittivity in wet yttrium-doped barium cerate”, (2012) Journal of Solid State Electrochemistry, DOI:10.1007/s10008-012-1916-z
  58. D. Vladikova, Z. Stoynov, G. Raikova, A. Thorel, A. Chesnaud, J. Abreu, M. Viviani, A. Barbucci, Z. Ilhan, P. Carpanese, S. Presto, Proc. 15th European Fuel Cell Forum 2011, 28 June – 1 July 2011, Lucerne Switzerland, Ch. 18/B1205, pp. 29-41.
  59. Daria Vladikova, Zdravko Stoynov, Gergana Raikova, Milena Krapchanska, Alain Thorel, Anthony Chesnaud, „Dual membrane fuel cell – impedance approach for proof of concept”, Proc. 9th International Symposium on Electrochemical Impedance Analysis, 02-05 June 2011, Sv. Andrija, Rovinj, Croatia (, Imp. Contrib. Online 9 (2011) pp.P6-1–P6-10), NSSN 03224-1130.
  60. J. Marcheva, R. Raicheff “Effect of heat treatment on stress-corrosion cracking of low-carbon steel in phosphate solutions” Proc. 8-th International congress “Machines, Technologies, Materials 2011”, Tech. Union Publ., Sofia, 2011, vol.1, pp.145-148. N.Saliyski, D. Kovacheva, M. Mladenov, K. Aleksandrova, R.Raicheff, “Nanosized spinel-spinel lithium ion battery”, Nanoscience & Nanotechnology, E. Balabanova, I. Dragieva (Eds.), Marin Drinov Publ. House, Sofia, 2011, pp. 170-173.
  61. R. Nikolov, D. Kovacheva, M. Mladenov, N. Velichkova, R. Raicheff, P. Tzvetkova, “On the relation between texture parameters and double layer capacitance of activated carbon”, J. Univ. Chem. Technology and Metallurgy 46, 2011, pp. 275-282.
  62. G. Raikova, D. Vladikova, Z. Stoinov, ”Differential impedance analysis of the cathode compartment in dual membrane fuel cell’ Bulg. Chem. Commun., 43, 2011, pp.133-137.
  63. M. Mladenov, N. Petrov, T. Budinova, V. Tsynsarski, N. Saliyski, D. Kovacheva, R. Raicheff, “Synthesis and electrochemical properties of electrode materials for supercapacitors”, Bulg. Chem. Commun., 43, 2011, pp.125-132, ISSN 0324-1130
  64. M. Krapchanska, D. Vladikova, G. Raikova, M. Slavova, Z. Stoinov, “Differential impedance analysis of BaCe0.85Y0.15O2.925 “, Bulg. Chem. Commun. 43, 2011, pp.120-124.
  65. M. Mladenov, N. Petrov, D. Kovacheva, R. Raicheff “Synthesis and electrochemical electrochemical properties of activated carbons and Li4Ti5O12 as electrode materials for supercapacitors”, J. Solid State Electrochem., Springer-Verlag, 2011.
  66.  Z. Ilhan, A. Ansar, N. Wagner, S. Presto, M.Viviani, A. Barbucci, D. Vladikova, Z. Stoynov, A. Thorel, “Towards understanding the dual membrane fuel cell (IDEAL Cell) using a metallic central membrane”, Solid Oxide Fuel Cells 12 (SOFC-XII) 35/1 (2011) 769-775.
  67. Massimo Viviani, Sabrina Presto, Antonio Barbucci, Maria P. Carpanese, Roberta Amendola, Alain S. Thorel, Anthony Chesnaud, Joao Abreu, Remi Costa, Zeynep Ilhan, Sayed-Asif Ansar, Daria E. Vladikova and Zdravko B. Stoynov, MRS Proceedings, 2011, Vol. 1330, mrss11-1330-j05-04 doi:10.1557/opl.2011.1338.
  68. D. Vladikova, Z. Stoynov, G. Raikova, A. Thorel, A. Chesnaud, J. Abreu, M. Viviani, A. Barbucci, S. Presto, P. Carpanese, “Impedance spectroscopy studies of dual membrane fuel cell”, Electrochim. Acta 56, 2011, pp.7955-7962.