As an energy storage device, battery has been rapid developed in recent years with the typical environmental problems such as consumption of resources and heavy metal pollution. Therefore, it is urgent to conduct a comprehensive analysis and in-depth interpretation of the environmental impact of the battery industry to reduce environmental pollutio. ••Environmental impact of LAB, LMB and LIPB are quantified with LCA.••Unformed plate manufacturing is the key process for LAB.••Assembly process and negative plate manufacturing are the key processes for LMB and LIPB.••Reduce-Reuse-Recycle principle is applied for the optimization of key process.The battery was invented in 1859 to convert chemical energy into electrical energy (Dyer et al., 2009, Kurzweil, 2010). Nowadays the main kinds of batteries are lead acid battery, lithium-ion batteries, and nickel-metal hydride batteries (Hu et al., 2016a, Hu et al., 2016b). China's battery production shows a rapid growth trend in recent years. The total output of large-scale battery enterprises are more than 220.7 GWh, accounting for 40% of the world's total output, which comes along with resource consumption and heavy metal pollution as the main environmental problems (Liu et al., 2015, Sun et al., 2017). Chinese government has issued some policies on batteries for further healthy and sustainable development of the industry. For example, from 2012 to 2015, “Lead acid battery industry access conditions” (MIIT and MEP, 2015), “Notice on the consumption of the battery paint” (MOF, 2015), “Safety requirements of portable electronic products with lithium-ion battery and batteries” (NSMC, 2013), “Cleaner production evaluation index system of battery industry” (NDRC et al., 2015), “Lithium-ion battery industry standard notice management Interim measures” (MIIT, 2016) and other policies have published to improve the battery industry access conditions and regulate the battery production management. In addition, the State Council issued “The 13th Five-Year Plan for Ecological Environment Protection” in 2016, which clearly stated to prevent and control heavy metal pollution caused by battery industry and other related ind. LAB, LMB and LIPB are carried out following the LCA procedure and ReCiPe midpoint (H) model analysis is performed. According to the normalized analysis results, the environmental impact categories are selected. The key processes and key substances are identified according to overall environmental impact. Traceability analysis is performed for proce. 3.1. Environmental impact analysisThe ReCiPe midpoint (H) model is used to analyze the environmental impact of different battery production processes. The environmental impact results of the characterization calculation at the midpoint are shown in Table 5.Table 5. Midpoint results of the life cycle impact assessment.a“1,4-DB eq” is the default unit for toxicity. “1,4-DB” is a chemical substance (1,4-dichlorobenzene). “eq” means equivalent (Ahlroth and Finnveden, 2011).Table 5 showed that the 3 types of battery have different effects on the 18 environmental impacts of the ReCiPe model. Except ionizing radiation, agricultural land occupation and water consumption, the LAB production process has the greatest impact on the rest of the environmental impact categories. In addition, LMB production process has the greatest impact on ionizing radiation and water depletion. Among all the 18 environmental impact categories, the lithium iron phosphate production process has the least environmental impact.In order to further analyze the contribution of 18 environmental impact categories to the overall environmental impact at the midpoint, the results are normalized at the midpoint (Fig. 3).3.2. Key process identificationUsing.
