For use in room-temperature electrodeposition of magnesium（Mg）metal, aging variation was studied to assess the electrochemical properties of a mixed system: an ionic liquid（IL）and a Grignard reagent. Cyclic voltammograms of a mixture of an IL, i.e. trimethylhexylammonium bis（trifluoromethylsulfonyl）amide（TMHA-Tf₂N; Tf＝CF₃SO₂）, and a Grignard reagent, i.e., ethylmagnesium bromide（EtMgBr）in tetrahydrofuran（THF）, showed redox currents for Mg metal deposition and dissolution. Similarly to other IL-Grignard mixed electrolyte solutions, the mixture examined in this study was found to have larger redox current than neat Grignard electrolyte solutions. Voltammograms for one-day-aged TMHA-Tf₂N-EtMgBr-in-THF mixtures showed smaller or almost no redox current. Furthermore, adding a Grignard reagent to the one-day-aged IL-Grignard mixture did not improve the electrochemical properties. Therefore, redox property deterioration was not attributable to a sizable decrease in the electrochemically active species or a shift of the Schlenk equilibrium in 2EtMgBr ↔ Et₂Mg＋MgBr₂. From our results, we speculate that Lewis acidic IL cations and Lewis basic Grignard species reacted gradually to form redox-inactive species or inhibitor（s）for the electrochemical deposition of Mg.

An impedance-response-based copper wiring corrosion sensor（CCS）was fabricated using screen printing technique. Filter paper（FP）containing 1 M NaCl solution was set on the zigzag conducting parts of the CCS to control the wet area during impedance measurements using a two-electrode system. Arbitrary values of width w or length L of the FP were chosen to investigate the short circuit current in the direction along or crossing the conducting parts. Impedance spectra with different w values of the FP showed a loop on the Nyquist plane. Loop diameter d increased concomitantly with increasing w values of the FP. Part of the loop was observed in the impedance spectra with different L values of the FP. Values of d estimated from respective parts of the loop increased concomitantly with increasing L values of the FP. Results indicate that these loops are related to the copper-wiring / electrolyte solution interface and that d values increase concomitantly with increasing wet area on the conducting parts. Results of the electrochemical impedance simulation demonstrated the following: solution resistance R_sol is inversely related to the L values; the electric double layer capacitance C_dl increased linearly, concomitantly with increasing L values of the FP; and R_sol and the C_dl increased linearly, concomitantly with increasing w values of the FP. Results demonstrate that the impedance response is related closely to the short circuit current in the direction crossing the conducting parts of the CCS.