Study on the Crystallinity and Oxidation States of Nanoporous Anodized Tin Oxide Films Regulated by Annealing Treatment for Supercapacitor Application

Abstract

In this study, electrodeposition combined with anodization was employed to prepare a nanoporous tin oxide film on a pure copper substrate. It was found that annealing temperature played a critically significant role in regulating the crystallinity, pore size, and contents of different oxidation states of the anodized tin oxide film to affect the electrochemical performance. The study verified that SnO x films treated by optimized annealing at 500 °C with precisely controlling the nanoporous morphology and crystallinity displayed competitive specific capacitance at an appropriate ratio of Sn4+ to Sn2+. A maximum specific capacitance of 86.2 mF/cm2 could be achieved at this temperature, and the capacitance retention rate still exceeded 90% even after 8000 charge–discharge cycles. With properly designed annealing treatment, we implemented tin film anodization to obtain an optimized electrode with significantly enhanced electrochemical performance, which shows a promising application in the electrochemical field to prepare electrodes.

Morphological and semiconductive properties of the anodic oxide layers made on Fe3Al alloy by anodizing in tartaric-sulfuric acid mixture

“…Regarding the chemical composition analysis (Table 5 ), EDS analysis reveals higher contents of iron and aluminum and lower oxygen concentration compared to those from non-annealed films (Table 4 ). These findings suggest the occurrence of chemical reactions within the oxide layer, i.e., the oxygen from the oxide and the surrounding air atmosphere reacts with the aluminum and iron species 50 .…”

“…Although no clear correlation between electrolyte composition and morphology can be established, several studies reported the occurrence of diffusion processes during annealing. These diffusion phenomena usually lead to the coalescence and fusion of pores, thus resulting in the formation of larger and flatter structures, such as flakes 48 – 50 .…”

Anodization fabrication techniques and energy-related applications for nanostructured anodic films on transition metals

“…At present, anodization has become a widely used technique for preparing metal oxides with various nanostructures. In addition to transition metals, some non-transition metals, like tin, have also been anodized to fabricate nanomaterials with various unique properties [203][204][205][206][207][208] . However, compared with the highly ordered AAO, the anodized films on transition metals, such as Fe, Cu and Zn, showed fewer perfect nanostructures with relatively low degrees of ordering.…”

Simulation of Anodic Current and Optimization of the Fitting Equation and the Fitting Algorithm during Constant Voltage Anodization

“…In recent years, with the development of science and technology and the progress of the times, the demand of the society for high-performance materials has gradually expanded. Porous anodic oxides (PAOs) have shown considerable application potential in energy, environment, medical, and other fields due to their regular structure, large specific surface area, and ease to design. − Over the years, the research on PAOs has mostly focused on the preparation process and the application of porous structures. − However, there are few studies on the electrochemical anodization process of metals and the formation mechanism of porous structures. Therefore, the growth kinetic of PAO is still very controversial. − Based on the field-assisted dissolution (FAD) theory and the field-assisted ejection theory, a “top-down” mining model is proposed.…”