The role of nickel (Ni) as a critical metal in clean energy transition: applications, global distribution and occurrences, production-demand and phytomining

In 2022, nickel (Ni) was nominated as a critical metal due to its wide applications in the metal industry, especially in clean energy applications to achieve climate mitigation targets. Meantime, rapid industrialization and escalating demand for electronic battery manufacturing have increased global Ni consumption, and therefore available primary Ni resources will not be sufficient to cater to the demand. As a result, currently, the Ni supply chain is diversifying focusing on low-grade Ni resources which were previously considered as economically invaluable. This paper presents comprehensive study on different applications of Ni, existing high-grade Ni resources, mode of occurrence, and the production and future demand of Ni, and discusses the state of art on the different leaching and extraction methods to recover Ni from low-grade sources, such as mine tailings, galvanic sludge, electronic batteries, and serpentine soil. In addition, this paper highlights the current status of the Ni phytomining approaches in serpentine soil and its future perspectives. It is evident that a development of Ni phytomining industry as a carbon-neutral mining technique is essential to overcome Ni supply risk for the commercial production of Ni using low-grade resources. Finally, this study will evaluate the production of high-quality Ni from low-grade secondary sources.