Review of critical material studies

The cobalt crisis at the end of 20th century and the recent rare earth elements debate in World Trade Organisation (WTO) both showed the importance of certain materials to numerous industries and even to the economy, defence and politics of individual countries. This fact prompted some authorities to launch organisations which focus on these critical materials and conduct studies on them. A good understanding of current or potential future situations of criticality of materials can help stakeholders to make better decisions to mitigate the criticality issues or take measures in advance. Furthermore, a review of critical materials studies provides a global view of this research area and be served as a reference material for future critical material studies. However, there is not yet a comprehensive study on diagnosis of criticality. Only some studies focused on finding critical materials in one specific region, country or offering recommendations accordingly. Also no product level methodology is available publicly. Therefore, the purposes of this study are (1) to show existing works about critical materials; (2) to help readers who want to carry on a critical materials study by showing: extract definitions of criticality as well as methodologies for determining the critical materials, including dimensions, data sources etc.; (3) to illustrate a criticality research area map as well as research gaps. Studies on critical materials are still at an early stage, evaluation methodologies can be improved and more sectors and regions need critical materials studies.