Vinylene Carbonate as Co-Solvent for Low-Temperature Mixed Electrolyte Based Supercapacitors

Abstract

The electrochemical characteristics of supercapacitors consisting of molybdenum carbide derived carbon C(Mo2C) electrodes in 1M NaPF6 solutions in various mixtures (0.5–5%) of vinylene carbonate (VC) with propylene carbonate (PC) and ethyl acetate (EA) (1:1 by volume) have been studied using cyclic voltammetry, constant current charging/discharging and electrochemical impedance spectroscopy methods. The specific capacitance and series resistance values dependencies on the used solvent mixture and applied temperature (from −40°C to 60°C) have been established. The region of ideal polarizability has been established for C(Mo2C) electrodes in all electrolytes and temperatures investigated, except at T ≥ 40°C. Specific conductivity values have been measured and correlated with electrochemistry data. Limiting capacitance, calculated characteristic time constant and complex power values depend noticeably on the solvent mixture used in the electrolyte, i.e. on the viscosity and specific conductivity of the electrolyte solution. The studied electrolytes are potential candidates for low-temperature supercapacitors.

High-dimensional neural network potential for liquid electrolyte simulations

“…The QRNN computed density, Hvap and CV for each of the pure solvents are in excellent agreement with the experimental data 21,[48][49][50][51][52][53][54][55][56] as shown in Figure 2 (a), (b) and (c), respectively. Similarly, the OPLS4 gives good predictions of the density and the heat of vaporization for all the solvents but overestimates the Cv values as compared to experimental data 21,[48][49][50][51][52][53][54][55][56] .…”

Double Layer Impedance in Mixtures of Acetonitrile and Water

“…The strong dependence of the capacitance values on solvents has been applied to expanding the available voltage, improving the reversibility of charge‐discharge processes, selecting materials of cells and electrodes, and suppressing leakage of the charge. As industrial applications, mixed solvents have been used for developing properties of supercapacitors . Mixed solvents have an advantage in providing the opportunity to vary continuously the conditions.…”

Hard Carbon and Li4Ti5O12-Based Physically Mixed Anodes for Superior Li-Battery Performance with Significantly Reduced Li Content: A Case of Synergistic Materials Cooperation

“…At low frequencies, the Warburg component, that is, the sloping line corresponds to the diffusion process occurring in the bulk material. 27 The LTO–HC 20–80 mixed anode impedance resembles that of pristine HC, whereas that of the LTO–HC 50–50 mixed anode exhibits a second semicircle. The semicircle at high frequencies corresponds to the diffusion through pores of the electrode.…”