Supply Risk Propagation of Cobalt-containing Products Trade Network in the New Energy Vehicle Industry Chain

Cobalt is a key raw material in battery production for new-energy vehicles（NEVs）. The international trade in cobalt-containing products runs through the entire NEV industry chain; however, most countries are highly dependent on foreign cobalt mineral supplies, leading to widespread concerns over supply risks in the international community. This study constructed a multilayer trade network for cobalt-containing products in the NEV industry supply chain by integrating material flows and international trade data. Based on the network, a cascading failure model was employed to simulate the propagation of supply risks and analyze the characteristics and pathways of risk spread. The results indicate that（1） according to the structural characteristics of trade network for Co-containing products in the NEV industry chain, the trade network becomes denser, with a broader range of participating countries and larger risk propagation scale, as one moves downstream.（2） The main risk propagation pathway is amplified step-by-step along “Congo-Kinshasa-China-USA/Japan/Germany”. The upstream risks are transmitted midstream via strong connections between Congo-Kinshasa and China, whereas diffusion from midstream to downstream involves several NEV manufacturing countries, such as Japan and the USA.（3） China possesses strong risk transmission capabilities midstream and downstream, influencing 70% and 61% of trade participants, respectively. Although China exhibits strong intra-layer risk resistance, its ability to withstand upstream inter-layer risks from upstreak is weak. The present study identifies the key nodes and paths of supply risk propagation for Co-containing products in the NEV industry chain and provides a theoretical reference for the construction of a risk supervision and early warning system for the industry chain.