Seafloor minerals, many of which can be found in the deep ocean areas of the international waters, have attracted increasing attention over the last years due to the discovery of large volumes of deposits with high metal grades and to the growth in global demand for strategic minerals such as copper, nickel, cobalt, and rare earth. At the same time, the growing diffusion of electric vehicle batteries has had an impact on the demand for both land and deep-sea metal ores. This thesis provides a comprehensive analysis about the environmental, social and economic impacts associated with land and deep-sea mining operations of metallic minerals such as cobalt and manganese used for the production of EV batteries.