Life cycle assessment of lead-acid batteries used in electric bicycles in China

摘要

Electric bikes (e-bikes) have developed faster than any other mode of transport in China, which has stimulated the rapid growth of China's lead-acid battery (LAB) industry for more than a decade. This research undertook a life cycle assessment (LCA) for LABs used in e-bikes in China. Its purpose was to identify the key materials and processes that contribute most to impacts on the environment and public health within the life cycle of LABs, from materials extraction and processing, manufacture, transportation, use, and end-of-life. It also sought to find opportunities for improving the environmental profile of LABs. The results indicate that LABs use, as well as materials extraction and processing, have the largest environmental impacts within the life cycle of LABs. The former is responsible for 84% of the primary energy use and contributes the highest potentials to energy-related impacts, including global warming (86%) and acidification (69%). The latter, specifically the lead used in batteries, is the most important driver of impacts such as ozone depletion, photochemical smog, eutrophication, and carcinogenicity. Accordingly, battery reuse after refurbishment and recovery of materials in the end-of-life stage could significantly mitigate most of the overall life cycle impacts by reducing the consumption of virgin materials. However, currently, 95% of total lead emissions are released in the end-of-life stage due to improper management of the spent LABs recycling market in China, and these emissions causes 90% of total human toxicity potential. Battery manufacture only accounts for 3% of total lead emissions after the national cleanup action for heavy metal pollution. Moreover, sensitivity coefficients are employed to evaluate the reliability and uncertainty of the LCA results. Based on the findings, there are several substantial opportunities to further reduce the overall environmental impacts of LABs, such as prolonging the lifetime of LABs, reducing the consumption of metals in LABs, and improving the technology and management in the recovery of spent LABs. (C) 2015 Elsevier Ltd. All rights reserved.