Sea nodules are poised to play an increasingly critical role in supplying metals essential for the clean energy transition. The rising demand for metals such as copper, nickel, cobalt, and manganese—driven by the rapid expansion of electric mobility and associated battery technologies—underscores the need for alternative and sustainable metal sources. However, uneven resource distribution and the concentration of mineral value chains create significant supply chain risks, which have hindered investor interest in sea-based metal recovery to date. Key metals required for e-mobility applications are often concentrated in a limited number of countries, necessitating a policy shift towards efficient utilization of marine resources for establishing metal extraction facilities. This chapter explores an alternative and potentially more economical pathway: integrating sea resource exploitation with recycled resource processing to enhance the availability of critical metals. This approach could minimize the capital investment required for traditional sea-nodule-only processing plants by combining sea nodules with existing land-based recycling operations, such as spent lithium-ion battery black mass. The study highlights how such a combined model, leveraging existing nickel laterite processing plants or black mass recycling facilities, can achieve economic viability even with smaller sea-nodule supplies by enabling multi-metal production. Case studies are presented to illustrate how this integrated approach promotes enhanced circularity and reduces geopolitical risks, enabling the use of alternative and greener primary resources to meet future battery metal demands.