Characterization of Ag/Ag2SO4 system as reference electrode for in-situ electrochemical studies of advanced aqueous supercapacitors

Abstract

Silver metal covered by Ag 2 SO 4 was investigated as a reference electrode for flat three-electrode cells. The potential stability of the Ag/Ag 2 SO 4 electrode in neutral aqueous solutions utilized as electrolytes for asymmetric high-voltage supercapacitors is reported. It was found that the potential drift and temperature coefficient of this reference electrode are insignificant. Its use as an alternative to the Ag/AgCl electrode enables one to avoid the contamination of the supporting electrolyte solution by Cl − anions, which are oxidized earlier than water molecules and other oxygen-containing anions (SO 2− 4 or NO − 3). Using the data obtained from threeelectrode electrochemical measurements with the electrode in question, a graphene-carbon nanotube/MnO 2 supercapacitor cell accumulating 9.8 Wh kg −1 of specific energy at 1.75 V was built.

Fast and Scalable Hydrodynamic Synthesis of MnO2/Defect-Free Graphene Nanocomposites with High Rate Capability and Long Cycle Life

“…60,61 To demonstrate the effects of high electron and ion conductive IL-G on the electrochemical performance of 5-MnO 2 /IL-G, MnO S11). Notably, the specific capacitance of 507 F/g obtained at a high rate of 1000 mV/s for 5-MnO 2 /IL-G was still much higher than those of other previously reported metal oxide/carbon electrodes obtained even at lower rates, including MnO 2 /carbon aerogel (124 F/g at 5 mV/s), 62 3D-MnO 2 /CNT (182 F/g at 2 mV/s), 63 MnO 2 /RGO-activated carbon (123 F/g at 10 mV/s), 64 MnO 2 /RGO (23 F/g at 5 mV/s), 65 TiO 2 /graphene (250 F/g at 2 A/g), 66 VO X /carbon (191 F/g at 0.5 mV/s), 67 ZrO 2 /GO (299 F/g at 1 mV/s), 68 Co 3 O 4 /activated carbon (491 F/g at 0.5 A/g), 69 and Fe 3 O 4 / activated carbon (150 F/g at 3 A/g) 70 electrodes. The longterm stability of the electrode was further tested by applying sequential current densities of 1 and 10 A/g over 20 000 cycles.…”

Cyclic voltammetric study of tin hexacyanoferrate for aqueous battery applications

“…These electrodes were separated by two layers of a porous paper membrane (TF4030, Nippon Kodoshi), and a silver sulfate reference electrode fabricated as described in Ref. [22] was located between them. Its potential was +0.137 V vs. Ag/AgCl at 25 °C.…”

Electrochemical and physicochemical degradability evaluation of printed flexible carbon electrodes in seawater

“…Besides, silver is known to react with halides to form new components, and this has been thoroughly studied in literature in the form of chloride, iodine, and bromide sensors [14][15][16]. Silver can also react with sulphates to form Ag/AgSO 4 , which has been used as an alternative to the Ag/AgCl reference electrode (RE) [17,18]. Considering that silver readily reacts with components present in water bodies (e.g., NaCl, MgSO 4 ), which could rapidly deteriorate the performance and the lifetime of the sensor, and its high environmental impact, other options for the conductive path material should be explored.…”