Life cycle assessment of power batteries used in electric bicycles in China

Abstract

China has the largest number of electric bicycles (EBs) in the world; they use a considerable amount of batteries. Lead-acid batteries (LABs) are being gradually replaced with lithium-ion batteries (LIBs) in these EBs. It is necessary to explore the environmental impact of these batteries in China. This study quantified the full life cycle environmental performance of LABs (lead-antimony-cadmium, Pb–Sb–Cd, and lead-tin-calcium, Pb–Sn–Ca) and LIBs (lithium-nickel-cobalt-manganese, NCM, and lithium-iron-phosphate, LFP) through the life cycle assessment methodology. The results showed that the material extraction and processing and the battery use stages were the main processes that affected the overall environmental performance. The battery manufacturing and transportation stages had a negligible environmental impact, whereas the battery recycling could increase the environmental benefits of batteries. However, the environmental contribution of the end-of-life (EOL) stage of LIBs was not as good as LABs, especially for LFP batteries. Overall, LFP batteries had better environmental performance except for the highest carcinogenic human toxicity potentials caused by the Cr (VI) discharge from the copper production. Pb–Sn–Ca batteries had the lowest toxic potential to humans and water because of the use of cadmium-free technology. The advantages of NCM batteries over LABs were not obvious currently but had great potential for improvement. Scenarios for cycle life, recycling rate, echelon utilization, and repair and reuse of batteries were established to analyze opportunities to reduce the environmental impact of batteries. Then, several implications were proposed for the development of technology for batteries in EBs.