Quantitative analysis of the coupling coefficients between energy flow, value flow, and material flow in a Chinese lead-acid battery system

To reveal the historic characteristics of the material flow, energy flow and value flow in a lead-acid battery (LAB) system, a framework for the coupling relationship among the three flows was established based on material flow analysis and the characteristics of the energy and value flows. The coupling coefficients between energy and material (CCEM) and value and material (CCVM) were also defined. The investigation used by China as a case to study changes in stages and the historic evolution. The results show that the CCEM for lead in LABs was highest in the usage stage, approximately 5-16 times greater than in the other stages. The CCEM for production was almost twice as high for primary lead as for secondary lead, and the CCEM was lowest for the fabrication and product manufacture stage. The CCVM for lead in LABs was 2.5-6 times higher than for other types of lead. The CCVM was lower for scrap lead than for lead ore, and the CCVM was approximately 1.7 times higher for refined lead than for scrap and refined lead. For lead trade, CCVM was correlated with domestic and overseas markets. From 1990 to 2014, the CCEM for each stage was in decline, whereas the opposite was the case for CCVM. The influencing factors were analyzed in terms of resources, the environment, and markets. Increasing the circulation rate of scrap lead is an effective way to rapidly save resources, reduce lead pollution, and promote a circular economy. The limitations and potential value of the study are also highlighted, and future research is outlined.