Estimation of Diffusion-Kinetic and Thermodynamic Properties of Al‑Sm-H Alloys
Authors: Lukyanova Victoria O. , Gots Irina Yu. 
Published: December 2020

Metal hydride systems for hydrogen storage are now commercially manufactured and the demand for them is constantly growing. Metal hydrides have the following features: a unique combination of properties of metal-hydrogen systems; extremely high volumetric densities of hydrogen atoms in the metal matrix; a wide range of operating pressures and temperatures; the selectivity of the hydrogen absorption process; significant changes in the physical properties of the metal when it is saturated with hydrogen; their catalytic activity, etc. The purpose of our research was to study the effect of the temperature of cathodic polarisation on the diffusion-kinetic, thermodynamic, and physical properties of Al-Sm-H alloys.In our study we used electrodes of Al-Sm-H alloys obtained electrochemically using cathodic intercalation from a 0.5 M dimethylformamide solution of samarium salicylate at Еcp = –2.9 V (relative to the non-aqueous silver chloride electrode) and the temperature of 25 °С for 1 hour. We used the electromotive force method to determine the thermodynamic properties: Gibbs free energy (ΔG), entropy (ΔS), and enthalpy (ΔH). The potentiostatic method was used to calculate the diffusionkinetic properties: intercalation constants, adsorption, switching current density, and the diffusion coefficient. The microstructural analysis allowed us to determine the effect of the temperature on the changes in the surface morphology.The study showed that an increase in the temperature results in an increase in ΔG, ΔS, and ΔH, which means that at higher temperatures the degree of the system disorder increases. Nevertheless, the calculated characteristics comply with the existing literature.

References
1. Fateev V. N., Alexeeva O. K., Korobtsev S. V.,Seregina E. A., Fateeva T. V., Grigorev A. S., Aliyev A. Sh.Problems of accumulation and storage of hydrogen.Chemical Problems. 2018;16(4): 453–483. DOI:https://doi.org/10.32737/2221-8688-2018-4-453-483 (InRuss., abstract in Eng.)2. Kaur M., Pal K. Review on hydrogen storagematerials and methods from an electrochemical viewpoint.Journal of Energy Storage. 2019;23: 234–249.DOI: https://doi.org/10.1016/j.est.2019.03.0203. Kumar D., Muthukumar K. An overview on activationof aluminium-water reaction for enhancedhydrogen production. Journal of Alloys and Compounds.2020;835: 155189. DOI: https://doi.org/10.1016/j.jallcom.2020.1551894. Litvinov V., Okseniuk I., Shevchenko D., BobkovV. SIMS study of the surface of lanthanum-basedalloys. Ukrainian Journal of Physics. 2018;62(10): 845.DOI: https://doi.org/10.15407/ujpe62.10.08455. Schneemann A., White J. L., Kang S., Jeong S.,Wan L. F., Cho E. S., Heo T. W., Prendergast D., UrbanJ. J., Wood B. C., Allendorf M. D., Stavila V. Nanostructuredmetal hydrides for hydrogen storage. ChemicalReviews. 2018;118(22): 10775–10839. DOI: https://doi.org/10.1021/acs.chemrev.8b003136. Wang Y., Chen X., Zhang H., Xia G., Sun D., Yu X.Heterostructures built in metal hydrides for advancedhydrogen storage reversibility. Advanced Materials.2020;32(31): 2002647. DOI: https://doi.org/10.1002/adma.2020026477. von Colbe J. B., Ares J. R., Barale J., Baricco M.,Buckley C., Capurso G., Gallandate N., Grant D. M.,Guzik M. N.; Jacob I., Jensen E. H., Jensen T., Jepsen J.,Klassen T., Lototskyy M. V., Manickam K., Montone A.,Puszkiel J., Sartori S., Sheppard D. A., Stuart A., WalkerG., Webb C. J.,Yang H.,Yartys V., Züttel A., DornheimM. Application of hydrides in hydrogen storageand compression: Achievements, outlook and perspectives.International Journal of Hydrogen Energy.2019;44(15): 7780–7808. DOI: https://doi.org/10.1016/j.ijhydene.2019.01.1048. Milanese C., Jensen T. R., Hauback B. C., PistiddaC., Dornheim M., Yang H., Lombardo L., Zuettel A.,Filinchuk Y., Ngene P., de Jongh P. E., Buckley C. E.,Dematteis E. M., Baricco M. Complex hydrides forenergy storage. International Journal of Hydrogen Energy.2019;44(15): 7860–7874. DOI: https://doi.org/10.1016/j.ijhydene.2018.11.2089. Abe J. O., Popoola A. P. I., Ajenifuja E., PopoolaO. M. Hydrogen energy, economy and storage: reviewand recommendation. International Journal of HydrogenEnergy. 2019;44(29): 15072–15086. DOI: https://doi.org/10.1016/j.ijhydene.2019.04.06810. He T., Cao H., Chen P. Complex hydrides forenergy storage, conversion, and utilization. AdvancedMaterials. 2019;31(50): 1902757. DOI: https://doi.org/10.1002/adma.20190275711. Luo Y., Wang Q., Li J., Xu F., Sun L., Zou Y.,Chua H., Li B., Zhang K. Enhanced hydrogen storage/sensing of metal hydrides by nanomodification. MaterialsToday Nano. 2020;9: 100071. DOI: https://doi.org/10.1016/j.mtnano.2019.10007112. Gambini M., Stilo T., Vellini M. Hydrogen storagesystems for fuel cells: Comparison between highand low-temperature metal hydrides. InternationalJournal of Hydrogen Energy. 2019;44(29): 15118–15134.DOI: https://doi.org/10.1016/j.ijhydene.2019.04.08313. Kim, K. C. A review on design strategies formetal hydrides with enhanced reaction thermodynamicsfor hydrogen storage applications. InternationalJournal of Energy Research. 2018;42(4): 1455–1468.DOI: https://doi.org/10.1002/er.391914. Oliveira A. C., Pavão A. C. Theoretical study ofhydrogen storage in metal hydrides. Journal of MolecularModelling. 2018;24(6): 127. DOI: https://doi.org/10.1007/s00894-018-3661-415. Møller K. T., Sheppard D., Ravnsbæk D. B.,Buckley C. E., Akiba E., Li H. W., Jensen T. R. Complexmetal hydrides for hydrogen, thermal and electrochemicalenergy storage. Energies. 2017;10(10): 1645.DOI: https://doi.org/10.3390/en1010164516. Huot J., Cuevas F., Deledda S., Edalati K., FilinchukY., Grosdidier T., Hauback B.C., Heere M., JensenT. R., Latroch M., Sartori S. Mechanochemistry ofmetal hydrides: Recent advances. Materials.2019;12(17): 2778. DOI: https://doi.org/10.3390/ma1217277817. Tarasov B. P., Fursikov P. V., Volodin A. A., BocharnikovM. S., Shimkus Y. Y., Kashin A. M., YartyscV. A., Chidzivad S., Pasupathid S., Lotot skyy M. V. Metal hydride hydrogen storage and compressionsystems for energy storage technologies. InternationalJournal of Hydrogen Energy. 2020. DOI:https://doi.org/10.1016/j.ijhydene.2020.07.08518. Zhao H., Xia J., Yin D., Luo M., Yan C., Du Y.Rare earth incorporated electrode materials for advancedenergy storage. Coordination Chemistry Reviews.2019;390: 32–49. DOI: https://doi.org/10.1016/j.ccr.2019.03.01119. Guzik M. N., Mohtadi R., Sartori S. Lightweightcomplex metal hydrides for Li-, Na-, and Mg-basedbatteries. Journal of Materials Research. 2019;34(6):877–904. DOI: https://doi.org/10.1557/jmr.2019.8220. Edward P. P., Kuznetsov V. L., David W. I. F.(2007). Hydrogen energy. Philosophical Transactions ofthe Royal Society A: Mathematical, Physical and EngineeringSciences. 2007;365(1853): 1043–1056. DOI:https://doi.org/10.1098/rsta.2006.196521. Weidenthaler C. Crystal structure evolution ofcomplex metal aluminum hydrides upon hydrogenrelease. Journal of Energy Chemistry. 2020;42: 133–143.DOI: https://doi.org/10.1016/j.jechem.2019.05.02622. Kunkel N., Wylezich T. Recent advances in rareearth-doped hydrides. Zeitschrift für Anorganische undAllgemeine Chemie. 2019;645(3): 137–145. DOI:https://doi.org/10.1002/zaac.20180040823. Milanese C., Garroni S., Gennari F., Marini A.,Klassen T., Dornheim M., Pistidda, C. Solid state hydrogenstorage in alanates and alanate-based compounds:A review. Metals. 2018;8(8): 567. DOI: https://doi.org/10.3390/met808056724. Gots I. Y., Lukyanova V. O. Influence of theintroducing rare-earth metal on the strength of thealuminum electrodes. Perspektivnye Materialy. 2020;2:39–47. DOI: https://doi.org/10.30791/1028-978x-2020-2-39-4725. Krapivnyj N. G. Opredelenie kineticheskihparametrov stadii proniknovenija vodoroda v metallynestacionarnym jelektrohimicheskim metodom[Determination of the kinetic parameters of the stageof hydrogen penetration into metals by a nonstationaryelectrochemical method] Electrochemistry. 1981;17(5):672–677. (In Russ.)26. Krapivnyj N. G. Primenenie jelektrohimicheskojjekstrakcii dlja izuchenija navodorozhivanie metallov[Application of electrochemical extraction to the studyof the hydrogenation of metals]. Electrochemistry,1982;18 (9): 1174–1178. (In Russ.)27. Pridatko K. I., Churikov A. V., Volgin M. A.Determination of lithium diffusion rate by pulsepotentiostatic method. Electrochemical Energetics.2003;3(4): 184–191. (In Russ., abstract in Eng.)Available at: https://energetica.sgu.ru/ru/articles/opredelenie-skorosti-diffuzii-litiya-impulsnympotenciostaticheskim-metodom28. Ol’shanskaja L. N., Terina E. M., Nichvolodin A. G.Thermodynamic characteristics of lithium intercalationin С8СrO3 electrode modified by addition ofgraphitizated soot. Electrochemical Energetics.2001;1(4): 49–53. (In Russ., abstract in Eng.) Availablea t : https://energetica.sgu.ru/ru/articles/termodinamicheskie-harakteristiki-interkalatovlitiya-v-s8cro3-elektrode-modificirovannom29. Patrikeev Yu.B., Filand Yu.M. Splavy-nakopitelivodoroda na osnove RZJe dlja jenergopreobrazujushhihustrojstv [Hydrogen-storage alloys for energyconversion devices]. Alternativnaya Energetika iEkologiya = Alternative Energy and Ecology. 2006;7: 32.(in Russ.) Available at: https://elibrary.ru/item.asp?id=942837230. Golovin P. V., Medvedeva N. A., Skrjabina N. E.Katodnoe povedenie splavov na osnove titana v reakciivydelenija vodoroda [Cathodic behavior of titaniumbasedalloys in the hydrogen evolution reaction].Bulletin of the Technological University. 2012;15(17):58–61. (In Russ.) Available at: https://elibrary.ru/item.asp?id=18125773