Vmp3 potentiostat

The ionic conductivity was determined by AC impedance spectroscopy using either custom-made stainless steel cells for liquid electrolytes or aSwagelok-type cells for membranes. The cells were assembled in an argon-atmosphere drybox (<1 ppm H₂O). Conductivity tests were performed by heating the samples in a Lauda E 300 thermostat. In regards to liquid electrolytes, samples were tested from −10 to 60 °C. For membranes, prior to conductivity measurements, cells were kept at 80 °C for 1 h in order to thermally condition the membrane, and then tested down to 20 °C. Samples containing the same salt and solvent, but at different concentrations, were tested at the same time. Impedance tests were performed by applying 5 mV amplitude signal from 500 kHz to 100 Hz using a VMP3 potentiostat from Bio-logic Science Instruments. Impedance data were evaluated by EC-lab software.

Cyclic voltammetry was performed using a VMP-3 potentiostat (Biologic
Science Instruments) in a three-electrode setup, employing a platinum
wire as the counter electrode, Ag/AgCl as the reference electrode,
and glassy carbon as the working electrode. Hydrogels were fabricated
by depositing 5 μL of the ink onto the glassy carbon electrode,
followed by a photopolymerization step with UV light irradiation.
Finally, they were cleaned in water for 5 min. 0.1 M NaCl aqueous
solution was used as the electrolyte, and it was purged with nitrogen
for 15 min before the experiment. Cyclic voltammetry measurements
were carried out in the potential range of −0.2 to 0.5 V vs.
Ag/AgCl at 20 mV s^–1 and 20, 50, 100, 150, and 200
mV s^–1 for the scan rate experiment.

Galvanostatic charging
and discharging cycles were conducted on the NMC 811|graphite coin
cells, using a BaSyTec CTS Battery Test System, in a voltage range
of 2.8–4.3 V. After 8 h rest at open circuit potential, the
electrochemical response was tested at different C-rates: 0.1C, 0.5C,
1C, 2C, 3C, 5C and, finally, a cycling of 90 cycles at 0.5C. To calculate
the C-rate, the theoretical capacity of NMC 811 active material was
considered (200 mAh g^–1), which was provided by
the supplier. Three samples of each binder were studied.
Electrochemical
impedance spectroscopy (EIS) measurements were performed in two stages,
after the first cycle of formation and after the cycling with a voltage
amplitude of 10 mV and a frequency range varying from 1 MHz to 1 mHz,
utilizing a VMP-3 potentiostat (Biologic Science Instruments).

Aluminum blocking electrode cells were assembled inside an argon glovebox and used to obtain ionic conductivities of the electrolytes using AC impedance spectroscopy. The casted film was to punch out 5/16 in. diameter electrolyte discs. The thickness of the electrolyte was measured using a micrometer. Similarly, aluminum foil was used to obtain electrodes with a diameter of 1/4 in. Two aluminum electrodes were mechanically pressed on either side of the electrolyte. Aluminum tabs were used as current collectors and placed over the blocking electrodes. The entire cell was vacuum sealed in the pouch material.
A Biologic VMP3 potentiostat was used to obtain complex AC impedance spectroscopy measurements for a frequency range of 1MHz–100 mHz with an amplitude of 50 mV. The Nyquist plot data were fit to an equivalent circuit to extract out the value for the bulk impedance, R_b. The ionic conductivity, κ, was calculated using $\kappa =\frac{L_{el}}{a{R}_{\mathrm{b}}},$ where a is the area of the blocking electrode and L_el is the thickness of the electrolyte measured using a micrometer. All measurements were taken at 90°C.

Electrochemical characterization was performed with a 3-electrode system that included a Pt wire as the counter electrode, a Ag/AgCl wire as the reference electrode and the gold microelectrodes from the silk-parylene probe as the working electrodes. EIS and cyclic voltammetry (CV) were performed using a Bio-Logic VMP3 potentiostat. CV was performed in PBS at room temperature by potential sweeping between −0.6 and +0.6 V at 200 mV/s vs. Ag/AgCl reference, allowing cathodal charge storage capacity (CSCc) evaluation^{37 (link),38 (link)}. EIS was also performed in PBS at room temperature by applying a 10 mV sine wave at frequencies ranging from 10 Hz to 7 MHz. Improved electrical properties were achieved by PEDOT:PSS deposition. CV was performed in EDOT:NaPSS solution (10 mM:34 mM) at room temperature by potential sweeping between −0.7 and +1 V at 10 mV/s vs. Ag/AgCl reference. CV and EIS were then performed again to compare the evolution of the CSCc, impedance, phase, and Nyquist results.

EIS was conducted with a BioLogic VMP3 potentiostat in the frequency range of 500 mHz to 1 MHz with a 50 mV AC amplitude. To measure the EIS of the grass ionic cables, two titanium metal strips were attached to the ends of the grass cable, where the LiNO₃ soaked cotton was used to wrap the metal to the end of the grass cables to achieve ionic connections. The voltage profiles of the electron battery were recorded between the cathode and the lithium metal reference electrode located near the cathode. Note that the anode and cathode were connected by an electrical cable. In the experiments, a Keithley 2,400 SourceMeter was connected to the circuit to measure the current.