In situ preparation of CuCl cubic particles on the commercial copper foil: its significant facilitation to the electrochemical performance of the commercial graphite and its unexpected photochromic behavior

• Published in: Journal of alloys and compounds Vol. 835; p. 155302
• Main Authors: Ding, Keqiang, Qu, Runling, Zhou, Lanjun, Zhang, Dongyue, Chen, Jiasheng, He, Xiangming, Wang, Li, Wang, Hui, Dou, Hongmin
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-09-2020; Elsevier BV
• Subjects: Color; Commercial graphite; Copper; Copper chloride; CuCl; Discharge; Electrochemical analysis; Enhanced electrochemical performance; Graphite; Ionic liquid; Ionic liquids; Light sources; Metal foils; Photochromic behavior; Photochromism; Room temperature; Stealth technology; Submerging; X ray photoelectron spectroscopy; CuCl; Commercial graphite; Enhanced electrochemical performance; Photochromic behavior; Ionic liquid
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.155302

An immersion method employing the commercial copper foil, CuSO4 solution and an ionic liquid of 1-butyl-3-methylimidazole chloride as the starting materials for preparing cuprous chloride (CuCl) on the surface of commercial copper foil (denoted as CuCl/Cu) at room temperature is developed in this work for the first time. As verified by the SEM images, a large number of cubic particles are prepared on the surface of the commercial copper foil after a simple immersion process, and XRD and XPS analysis substantially indicate that these synthesized cubic particles are CuCl particles. Interestingly, the initial discharge capacity of the commercial graphite at 0.1A g−1 is increased from 263 mAh g−1 on the commercial copper foil to 681 mAh g−1 on CuCl/Cu. And even at 1.0 A g−1 after 100 cycles, the discharge capacity of the graphite on CuCl/Cu is 128 mAh g−1, still 3.7 times larger than that on the Cu foil (34 mAh g−1). Incredibly, the color of CuCl cubic particles can vary from coppery color to black when it is illuminated by a light source for 30 min, suggesting that the as-prepared CuCl cubic particles are a kind of photochromic materials, showing a potential application in the field of military stealth materials.
Cubic particles of CuCl with a size close to 120 nm were prepared on the surface of the commercial copper foil at room temperature through an ionic liquid-present method. And it was indicated that the discharge capacity of the commercial graphite on the CuCl/Cu after 100 cycles at 1A g−1 was 128 mAh g−1, being 3.7 times higher than that on the commercial copper foil (34 mAh g−1). Most interestingly, it was found that the color of the as-prepared CuCl particles could vary from copper color to a black color when it was illuminated for a period of time, and when it was immersed in the as-used solution again, its color returned to its original color partly. [Display omitted]
•Cubic particles of CuCl with a size close to 120 nm were prepared at room temperature.•A preparation system having an ionic liquids was developed for preparing CuCl.•Discharge capacity of graphite on CuCl/Cu at 1A g−1 after 100 cycles was 128 mAhg−1.•As-prepared CuCl particles were a photochromic material.