Cradle-to-Gate and Use-Phase Carbon Footprint of a Commercial Plug-in Hybrid Electric Vehicle Lithium-Ion Battery.

Abstract

Increased use of vehicle electrification to reduce greenhouse gas (GHG) emissions has led to the need for an accurate and comprehensive assessment of the carbon footprint of traction batteries. Unfortunately, there are few lifecycle assessments (LCAs) of commercial lithium-ion batteries available in the literature, and those that are available focus on the cradle-to-gate stage, often with little or no consideration of the use phase. To address this shortfall, we report both cradle-to-gate and use-phase GHG emissions for the 2020 Model Year Ford Explorer plug-in hybrid electric vehicle (PHEV) NMC622 battery. Using primary industry data for battery design and manufacturing, cradle-to-gate emissions are estimated to be 1.38 t CO2e (101 kg CO2e/kWh), with 78% from materials and parts production and 22% from cell, module, and pack manufacturing. Using mass-induced energy consumptions of 0.6 and 1.6 kWh/(100 km 100 kg) for charge-depleting and -sustaining modes, respectively, the mass-induced use-phase emission of the battery is estimated to be 1.04 t CO2e. We show that battery emissions during the cradle-to-gate and use phases are comparable and that both phases need to be considered. A holistic and harmonized LCA approach that includes battery use is required to reduce carbon footprint uncertainties and guide future battery designs.