The compatibility of Ti, Cr, Ni, Fe, Al, steel type 304, Inconel 625, Hastelloy B and carbon coated current collectors with bisamide based electrolyte for Mg-batteries was investigated. Pitting corrosion of current collectors made from 3d-transition metals and steel type 304 was observed at potentials between 2.2-3.1 V vs. Mg/Mg 2+ . Anodic stability up to 3.8 V and resistance against corrosion for 48 h at a potential of 2.5 V vs. Mg/Mg 2+ and above was found for Inconel 625, Hastelloy B, graphite and carbon coated Al foil. © The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. [DOI: 10.1149/2.0111501eel] All rights reserved.Manuscript submitted October 9, 2014; revised manuscript received November 10, 2014. Published November 18, 2014 Recently Mg batteries have gained large interest due to the high theoretical energy density of Mg (2233 mAh g −1 and 3832 mAh cm −3 , respectively) but also because of the comparable low price, high abundance and the non-toxic properties of Mg.1,2 In contrast to metallic Li, no dendrite formation has been observed during electrochemical cycling of Mg.3,4 Thus, the technical application of metallic Mg anodes for secondary batteries with liquid electrolyte is not hampered by safety concerns as they exist for metallic Li. As the energy density of a battery is determined by the capacity of the electrode materials and by the potential difference between the anode and the cathode, both should be as high as possible. However, high operation potentials increase the driving force for oxidative decomposition of the electrolyte as well as for corrosion of the current collector at the cathode. Anodic stabilities of electrolytes exceeding 3 V vs. Mg/Mg 2+ have been demonstrated recently. [5][6][7] However, until now all electrolytes for Mg batteries with good electrochemical performance (i.e. large voltage window, compatibility with metallic Mg and high ionic conductivity) contain chlorine, which was found to cause severe corrosion of current collectors made from Cu, Al, Ti and stainless steel.
2,8,9Recently we developed a synthesis for bisamide based electrolytes with unprecedented anodic stability by reaction of magnesiumbis(hexamethyldisilazide) [(HMDS) 2 Mg] with AlCl 3 in different aprotic solvents, which are compatible with sulfur cathodes. 5,10 In order to utilize such electrolytes for magnesium batteries, we have now studied the corrosion behavior of various metals and steels and investigated if corrosion can be mitigated by a carbon coating.
ExperimentalChronoamperometry and linear sweep voltammetry of current collectors was conducted vs. Mg foil, (Goodfellow, 99.99 %) in two...
