Material feasibility and environmental impacts of critical metals in NMC cathodes under a sustainable framework for electric vehicles

Abstract

The rapid growth of electric vehicles (EVs) emphasizes the urgent need for sustainable battery manufacturing practices, particularly in sourcing critical elements like lithium, nickel, manganese, and cobalt. This study employs a life cycle assessment approach to evaluate the environmental and energy impacts of recycling nickel–manganese–cobalt oxide (NMC) cathodes from spent lithium-ion batteries compared with those of the primary extraction of these metals from nickel lateritic ores. Lithium recycling is similarly assessed against conventional processing from spodumene ore. The results clearly indicate that recycling is the more sustainable option, offering higher yields with significantly lower energy demands and reduced environmental burdens. Specifically, the global warming potential associated with recycling 1 kg of NMC cells is 5.97 kg CO₂-eq, compared with 109.9 kg CO₂-eq for primary extraction to acquire a similar yield of metals. Additionally, the cumulative energy demand for primary extraction is 20-fold higher, requiring 1415.2 MJ compared to 70.5 MJ required for recycling for spent batteries. Moreover, sensitivity analysis reveals that the electricity mix plays a crucial role in shaping the environmental profile of recycling processes. Transitioning to cleaner, renewable energy sources could further reduce impacts across all evaluated categories. Overall, this study highlights the essential role of recycling in decreasing reliance on virgin raw materials, conserving finite mineral resources, and accelerating the shift toward a circular and sustainable battery economy.