Electrochemical Performance of Titania 3D Nanonetwork Electrodes Induced by Pulse Ionization at Varied Pulse Repetitions

Abstract

Pulse ionized titania 3D-nanonetworks (T3DN) are emerging materials for fabricating binder-free and carbon-free electrodes for electrochemical energy storage devices. In this article, we investigate the effect of the one of the most important fabrication parameters, pulse frequency, for optimizing supercapacitor efficiency. A series of coin cell batteries with laser-induced electrodes was fabricated; the effect of pulse frequency on oxidation levels and material properties was studied using both experimental and theoretical analysis. Also, detailed electrochemical tests including cyclic voltammetry (CV), charge/discharge, and electrochemical impedance spectroscopy (EIS) were conducted to better understand the effect of pulse frequency on the electrochemical performance of the fabricated devices. The results show that at a frequency of 600 kHz, more T3DN were observed due to the higher temperature and stabler formation of the plasma plume, which resulted in better performance of the fabricated supercapacitors; specific capacitances of samples fabricated at 600 kHz and 1200 kHz were calculated to be 59.85 and 54.39 mF/g at 500 mV/s, respectively.

A review on the advances in electrochemical capacitive charge storage in transition metal oxide electrodes for pseudocapacitors

“…This allows the surface ionization with oxygen presence in normal room conditions which lead to formation of titanium oxide as can be seen in EDX in Figure 18C. The formation of the oxidation layer allows rapid, reversible redox reactions at the surface 200,322 proving excellent for redox‐favored supercapacitors. Another proof of the method was demonstrated in work of Khot et al, in which a Ni sheet was directly irradiated with ultra‐fast pulses with varying power densities.…”

“…A common trend is that when the scan rate increases, the capacitive contribution becomes dominant, whereas at lower scan rates, the opposite is observed. [197][198][199][200][201] While the Dunn method provides a representation of contributions, an even quicker method to verify the contribution is by obtaining the b value by the power law relationship 69,202 :…”

“…Since slower scan rates allow enough time for ions in the electrolyte to diffuse, it is essential to gather slower scan rates. A common trend is that when the scan rate increases, the capacitive contribution becomes dominant, whereas at lower scan rates, the opposite is observed 197‐201 …”

“…Near the oxide layer, increased charge storage due to faradic contribution is observed 211 . Many TMOs, such as RuO 2 , MnO 2 , NiO, Co 3 O 4 , 212 NiCo 2 O 4 , 213 V 2 O 5 , 214 ZnO, 215 Fe 3 O 4 , 216 TiO 2 , 200 CuO, 217 SnO 2 , 218 WO 3 , 219 and many more, 164,220 are modified and nanoengineered for development or fabrication of electrodes in electrochemical capacitors due to their remarkable thermal stability and excellent theoretical capacitance 221 . Some of these TMOs are abundant in nature and readily available.…”

Formation of NiO Thin-Film via Picosecond Laser Pulses for Energy Storage Electrode Fabrication

“…There are several drawbacks to many of the synthesis processes such as post treatment, multi-step, harmful chemical environment, and time-consuming process. In this paper, simple irradiation of Ni, a transition metal is oxidized via ultra-short pulse laser in ambient temperature and pressure to develop 3D nanostructures resulting in formation of pseudocapacitance [7].…”