Status of life cycle inventories for batteries

This study reviews existing life-cycle inventory (LCI) results for cradle-to-gate (ctg) environmental assessments of lead-acid (PbA), nickel-cadmium (NiCd), nickel-metal hydride (NiMH), sodium-sulfur (Na/S), and lithium-ion (Li-ion) batteries. LCI data are evaluated for the two stages of cradle-to-gate performance: battery material production and component fabrication and assembly into purchase ready batteries. Using existing production data on battery constituent materials, overall battery material production values were calculated and contrasted with published values for the five battery technologies. The comparison reveals a more prevalent absence of material production data for lithium ion batteries, though such data are also missing or dated for a few important constituent materials in nickel metal hydride, nickel cadmium, and sodium sulfur batteries (mischmetal hydrides, cadmium, beta-alumina). Despite the overall availability of material production data for lead acid batteries, updated results for lead and lead peroxide are also needed. On the other hand, LCI data for the commodity materials common to most batteries (steel, aluminum, plastics) are up to date and of high quality, though there is a need for comparable quality data for copper. Further, there is an almost total absence of published LCI data on recycled battery materials, an unfortunate state of affairs given the potential benefit of battery recycling. Although battery manufacturing processes have occasionally been well described, detailed quantitative information on energy and material flows are missing. For each battery, a comparison of battery material production with its manufacturing and assembly counterpart is discussed. Combustion and process emissions for battery production have also been included in our assessment. In cases where emissions were not reported in the original literature, we estimated them using fuels data if reported. Whether on a per kilogram or per watt-hour capacity basis, lead-acid batteries have the lowest cradle-to-gate production energy, and fewest carbon dioxide and criteria pollutant emissions. The other batteries have higher values in all three categories. (C) 2012 Elsevier Ltd. All rights reserved.