# Fileset

[advs71206-sup-0001-supmat.pdf](https://mdr.nims.go.jp/filesets/b62c08e2-ec6c-4525-97c7-b272005169a3/download)

## Creator

[Dedy Setiawan](https://orcid.org/0000-0003-3560-0869), [Omar Falyouna](https://orcid.org/0000-0003-4236-6433), [Toshihiko Mandai](https://orcid.org/0000-0002-2403-7794)

## Rights

[Creative Commons BY Attribution 4.0 International](https://creativecommons.org/licenses/by/4.0/)

## Other metadata

[Beyond Half‐Cell Success: Cathode‐Electrolyte Reactivity Driving Magnesium Battery Full‐Cell Degradation at Elevated Temperature](https://mdr.nims.go.jp/datasets/e8fbc8d9-fc5b-4f96-b04a-26610f13685e)

## Fulltext

Template for Electronic Submission to ACS JournalsS1  Supporting Information    Beyond Half-Cell Success: Cathode-Electrolyte Reactivity Driving Magnesium Battery Full-Cell Degradation at Elevated Temperature Dedy Setiawan*, A Omar Falyouna A and Toshihiko Mandai*, A    A. Research Center for Energy and Environmental Materials (GREEN), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044 Japan  E-mail: SETIAWAN.Dedy@nims.go.jp, MANDAI.Toshihiko@nims.go.jp           mailto:SETIAWAN.Dedy@nims.go.jpmailto:MANDAI.Toshihiko@nims.go.jpS2   Figure S1. (a) X-ray Rietveld refinement of VO2 powder. Space group : C 2/m, a = 12.065 (1) Å, b = 3.690 (1) Å, c = 6.419 (5) Å, β = 106.99 (1)°. (b) SEM image of VO2 powder.      Figure S2. Asymmetric cell test comparison employing Cu as a working electrode and Mg metal as counter and reference electrode at 30 °C and 60 °C with a current density of 1.0 mA cm−2. (b) The corresponding Coulombic efficiency at 30 °C.   S3   Figure S3. (a) Asymmetric cell test employing Cu as a working electrode and Mg metal as counter and reference electrode at 60 °C with a current density of 0.1 mA cm−2. (b) The corresponding Coulombic efficiency of the asymmetric cell test.     Figure S4. LSV profile of 0.3 M Mg[Al(hfip)4]2 in diglyme with carbon-coated Al foil as working electrode.   S4   Figure S5. Galvanostatic discharge-charge profile of the full cell comprising VO2 cathode and 0.3 M Mg[B(hfip)4]2 in diglyme as the electrolyte with a current density of 10 mA g−1 cycled at different temperatures; (a) 30 °C and (b) 60 °C.    Figure S6. SEM image of Mg metal anode surface cycled in three-electrode cell with VO2 as the cathode (a) after 1st cycle and (b) after 10th cycle.    S5   Figure S7. (a) SEM-EDX mapping of Mg metal surface after 1st cycle in three-electrode cell with VO2 as the cathode. (b) ToF-SIMS analysis of V+ spectra of Mg metal surface taken at two different spots, indicates the presence of vanadium.     Table S1. Elemental ratios estimated from the ICP-OES analysis on VO2 cathode  Sample Mass Ratio (%) Relative Atomic Ratio Mg V Mg V Pristine <0.005 1.3 0.00 1.00 1st Discharge 0.019 1.3 0.03 1.00 1st Charge <0.005 1.4 0.00 1.00 10th Discharge (0.3 V vs. Ag/Ag+) 0.079 1.2 0.14 1.00 10th Discharge (0.5 V vs. Ag/Ag+) 0.074 1.8 0.09 1.00      S6   Figure S8. ToF-SIMS analysis area on Mg metal surface cycled with 0.3 M Mg[Al(hfip)4]2 in diglyme electrolyte in (a) symmetric cell and (b) in full cell with VO2 as a cathode, respectively.  Figure S9. ToF-SIMS surface spectra of Mg metal cycled with 0.3 M Mg[Al(hfip)4]2 in diglyme electrolyte in (a), (b) symmetric cell and (c), (d) in full cell with VO2 as a cathode, respectively.