Nickel oxide (NiO) is considered one of the most promising positive anode materials for electrochromic supercapacitors. Nevertheless, a detailed mechanism of the electrochromic and energy storage process has yet to be unraveled. In this research, the charge storage mechanism of a NiO electrochromic electrode was investigated by combining the in-depth experimental and theoretical analyses. Experimentally, a kinetic analysis of the Li-ion behavior based on the cyclic voltammetry curves reveals the major contribution of surface capacitance versus total capacity, providing fast reaction kinetics and a highly reversible electrochromic performance. Theoretically, our model uncovers that Li ions prefer to adsorb at fcc sites on the NiO(1 1 1) surface, then diffuse horizontally over the plane, and finally migrate in the bulk. More significantly, the calculated theoretical surface capacity (106 mA h g −1 ) accounts for about 77.4% of the total experimental capacity (137 mA h g −1 ), indicating that the surface storage process dominates the whole charge storage, which is in accordance with the experimental results. This work provides a fundamental understanding of transition-metal oxides for application in electrochromic supercapacitors and can also promote the exploration of novel electrode materials for high-performance electrochromic supercapacitors.

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Corrosion—reactions occuring between engineering materials and their environment—can cause material failure and catastrophic accidents, which have a serious impact on economic development and social stability. Recently, super-hydrophobic coatings have received much attention due to their effectiveness in preventing engineering materials from further corrosion. In this paper, basic principles of wetting properties and corrosion protection mechanism of super-hydrophobic coatings are introduced firstly. Secondly, the fabrication methods by electrochemical surface engineering—including electrochemical anodization, micro-arc oxidation, electrochemical etching, and deposition—are presented. Finally, the stabilities and future directions of super-hydrophobic coatings are discussed in order to promote the movement of such coatings into real-world applications. The objective of this review is to bring a brief overview of the recent progress in the fabrication of super-hydrophobic coatings by electrochemical surface methods for corrosion protection of engineering materials.

Although super-hydrophobic surfaces have great application prospects in industry, their preparation cost and mechanical durability have limited their practical utilization. In this work, we presented a new low-cost process preparation for super-hydrophobic Co–Ni coating on carbon steel substrate via an electrodeposition route. The deposited Co–Ni coating with cauliflower-shaped micro-nano structures exhibited high super-hydrophobic properties with water contact angles over 161° after modification with 1H,1H,2H,2H-Perfluorooctyltrichlorosilane (PFTEOS). Evaluated by the linear abrasion methods, the super-hydrophobic coating can maintain super-hydrophobicity after abrasion distance of 12 m under the applied pressure of 5 kPa, which was attributed to the high cobalt content of the Co–Ni coating. Moreover, electrochemical tests showed that the super-hydrophobic Co–Ni coatings exhibited a good anti-corrosion performance thus providing an adequate protection to the carbon steel substrates.

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