Advancements in Electrodeposition for Precise Manufacturing and Sustainability

The term circular economy is often found in literature references such as scientific articles1 and socioeconomic reports.2 Simply expressed, the circular economy implies that the people living on Earth should reuse and recycle the products that are currently in use as long as possible and reduce the waste produced, thus reducing CO2 emissions. The latter goal is fundamental from the perspective of mitigating the well-known greenhouse effect and the consequent global warming observed at the planetary scale. Under these conditions, advanced electrodeposition processes can play a fundamental role in the optimization of materials use and in the reduction of the energetic footprint for a wide variety of industrial processes. The aim of the present paper is precisely to suggest how this is possible, showing readers the potential that electrodeposition holds for efficient manufacturing of many different products that have a huge significance for industry. The first part of the present article focuses on the use of molten salts in the context of iron and steel production, one of the most energy intensive and CO2 impactful industries. It shows how electrodeposition from molten salts can be used to refine iron from the corresponding ores. The second part of the paper focuses on the use of ionic liquids for advanced applications like urban mining, which is a part of this concept of circular economy. Urban mining involves the recovery of compounds, materials, and elements from objects, products or waste generated by people, which are originally derived from conventional mining.3 Among the many materials that can be recovered in this manner, the focus in this article is placed on rare earth elements (REEs). In addition to this application, the paper also demonstrates the applicability of ionic liquids to the fabrication of nanometric 3D structures, to the improvement of 3D printing processes, and to the realization of aerospace products. The last part of the article is a brief discussion of the implementation of wet metallization techniques (electrolytic and electroless deposition) in the manufacturing of 3D printed parts. A wealth of approaches is described, with a special focus on the technologies that are able to deposit metals selectively following specified patterns.