Unravelling the landscape of global cobalt trade: Patterns, robustness, and supply chain security

As a strategic mineral resource, cobalt is widely used in electrical, mechanical, chemical, aerospace and other fields. It is of great significance to assess the spatiotemporal evolution and robustness of global cobalt trade to fully understand the global cobalt supply chain security in the new era. To this end, this paper constructs a global cobalt trade network dataset since 2001, employs various complex network analysis methods, portrays the spatiotemporal patterns and evolution process of the global cobalt trade networks, analyzes the topological structures of the global cobalt trade networks, and further measures their structural robustness to provide valuable references for the cognition of global cobalt trade security. The results show that: (1) Global cobalt trade volume has been growing, and the trade links have become increasingly close, gradually forming spatial patterns with obvious hierarchical structures and prominent hub countries. (2) The hierarchical structures of the global cobalt trade networks have undergone significant changes, and the dominant positions of China and the Democratic Republic of the Congo in the global cobalt trade networks have become increasingly prominent. (3) The backbone structures of the global cobalt trade networks have been expanding and differentiating, forming huband-spoke organizational patterns dominated by a few hub countries such as the USA, Germany and China. A few hub countries dominate the entire network backbone structure, but this dominance is not monotonously enhanced. (4) The overall robustness of the global cobalt trade networks shows a declining trend. The dominance of a few nodes and edges in the network structure is becoming increasingly prominent. The cobalt supply will face higher potential risks and challenges once an important node fails or an edge is interrupted. Finally, this paper proposes relevant policy recommendations to promote cobalt trade cooperation and build a secure and stable cobalt supply chain system.