Three key questions have driven recent discussions of the energy and environmental impacts of automotive lithium-ion batteries. We address each of them, beginning with whether the energy intensity of producing all materials used in batteries or that of battery assembly is greater. Notably, battery assembly energy intensity depends on assembly facility throughput because energy consumption of equipment, especially the dry room, is mainly throughput-independent. Low-throughput facilities therefore will have higher energy intensities than near-capacity facilities. In our analysis, adopting an assembly energy intensity reflective of a low-throughput plant caused the assembly stage to dominate cradle-to-gate battery energy and environmental impact results. Results generated with an at-capacity assembly plant energy intensity, however, indicated cathode material production and aluminium use as a structural material were the drivers. Estimates of cradle-to-gate battery energy and environmental impacts must therefore be interpreted in light of assumptions made about assembly facility throughput. The second key question is whether battery recycling is worthwhile if battery assembly dominates battery cradle-to-gate impacts. In this case, even if recycled cathode materials are less energy and emissions intensive than virgin cathode materials, little energy and environmental benefit is obtained from their use because the energy consumed in assembly is so high. We reviewed the local impacts of metals recovery for cathode materials and concluded that avoiding or reducing these impacts, including SOx emissions and water contamination, is a key motivator of battery recycling regardless of the energy intensity of assembly. Finally, we address whether electric vehicles (EV) offer improved energy and environmental performance compared to internal combustion-engine vehicles (ICV). This analysis illustrated that, even if a battery assembly energy reflective of a low-throughput facility is adopted, EVs consume less petroleum and emit fewer greenhouse gases (GHG) than an ICV on a life-cycle basis. The only scenario in which an EV emitted more GHGs than an ICV was when it used solely coal-derived electricity as a fuel source. SOx emissions, however, were up to four times greater for EVs than ICVs. These emissions could be reduced through battery recycling.
In light of the increasing penetration of electric vehicles (EVs) in the global vehicle market, understanding the environmental impacts of lithium-ion batteries (LIBs) that characterize the EVs is key to sustainable EV deployment. This study analyzes the cradle-to-gate total energy use, greenhouse gas emissions, SOx, NOx, PM10 emissions, and water consumption associated with current industrial production of lithium nickel manganese cobalt oxide (NMC) batteries, with the battery life cycle analysis (LCA) module in the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model, which was recently updated with primary data collected from large-scale commercial battery material producers and automotive LIB manufacturers. The results show that active cathode material, aluminum, and energy use for cell production are the major contributors to the energy and environmental impacts of NMC batteries. However, this study also notes that the impacts could change significantly, depending on where in the world the battery is produced, and where the materials are sourced. In an effort to harmonize existing LCAs of automotive LIBs and guide future research, this study also lays out differences in life cycle inventories (LCIs) for key battery materials among existing LIB LCA studies, and identifies knowledge gaps.
This paper looks ahead, beyond the projected large-scale market penetration of vehicles containing advanced batteries, to the time when the spent batteries will be ready for final disposition. It describes a working system for recycling, using lead–acid battery recycling as a model. Recycling of automotive lithium-ion (Li-ion) batteries is more complicated and not yet established because few end-of-life batteries will need recycling for another decade. There is thus the opportunity now to obviate some of the technical, economic, and institutional roadblocks that might arise. The paper considers what actions can be started now to avoid the impediments to recycling and ensure that economical and sustainable options are available at the end of the batteries' useful life