A systematic review on sustainability assessment of electric vehicles: Knowledge gaps and future perspectives

Electric mobility is emerging all around the world to minimize environmental impacts, reduce dependency on petroleum, and diversify energy sources for transportation. Any emerging technology comes with uncertainties in terms of its environmental, economic, and social impacts on the global society, and history has shown that some technological changes have led also to great societal transformation thus shaping our future as humanity. Understanding, perceiving, and anticipating the potential changes are essential to managing as well as internalizing maximum benefits out of these technological advancements for a sustainable global community. In the literature, life cycle assessment approaches are mainly used to assess the potential environmental impacts of electric vehicles. Considering the potential impacts of emerging transportation technologies, traditional life cycle assessment is not sufficient to analyze economic and social impacts, ripple, side, or rebound effects, macro-economic impacts, and global-supply chain related impacts. In response to these knowledge gaps, traditional environmental life cycle assessment approaches are evolving into new more integrated, and broader approaches (e.g., life cycle sustainability assessment). This research aims to reveal research gaps in the sustainability assessment of electric vehicles and provide an outlook of the current state of knowledge, perspectives on research gaps, and potential ways for the adoption of integrated life-cycle modeling approaches. We conducted a comprehensive literature review focusing on sustainability assessment studies for emerging electric vehicle technologies for the period between 2009 and 2020 using the Scopus database. A total of 138 life cycle assessment studies focusing on electric and autonomous (electric) vehicles are analyzed. The reviewed studies are classified and analyzed based on sustainability indicators, life cycle approaches, life cycle phases, data sources and regions, and vehicle technology and class. We also compared the global warming potential of battery electric vehicles of different class sizes. According to the literature review, five major knowledge gaps are identified; 1) lack of socioeconomic assessment, 2) lack of integrated modeling approaches and macro-level assessment; 3) limited consideration of end-of-life management and circular economy applications, 4) underrepresented developing world; 5) underrepresented emerging technologies. The findings of this review can help researchers worldwide to overview the state-of-art and state-of-practice in the field of sustainability assessment of emerging technologies and electric vehicles.