Re-evaluation of the Global Warming Potential for the Production of Lithium-Ion Batteries with Nickel–Manganese–Cobalt Cathode Chemistries in China
Davide Bonalumi, Mehrshad Kolahchian Tabrizi
Abstract
This study proposes a unified life cycle inventory (LCI) for evaluating the global warming potential (GWP) impact of producing lithium-ion power batteries (LIBs) in China, the largest LIB producer worldwide. Using the open-access Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, a cradle-to-gate life cycle assessment is conducted for lithium–nickel–manganese–cobalt oxide (NMC) chemistries for electric vehicle applications. The LCI is obtained by coupling the GREET model with the data from studies on the Chinese battery industry to represent a more true-to-life approach. Brine, ore, and mixed sources of lithium are considered for the production of active cathode material. Two manufacturing scenarios are developed based on the plant capacity, and different approaches are developed for data acquisition. The bill of materials (BOMs) for each battery is extracted from the corresponding literature and applied to the proposed LCIs and manufacturing scenarios to be compared with the GWP value reported in the original study. The results show that for producing 1 kWh of battery energy storage, the overall GWP can vary from 89 to 169 kg CO2 eq. depending on the lithium source, manufacturing scenario, and the BOM. Similarly, the GWP impact associated with battery-grade material production differs from 70 to 115 kg CO2 eq. per kWh, where the effect of manufacturing scenarios is suspended. Also, the GWP impact of different NMC cathode chemistries’ production is discussed. It is found that, based on the BatPaC model, upon increasing the nickel content, the GWP impact slightly decreases. However, using different BOMs, NMC111 cathode chemistry can result in a smaller GWP impact compared to NMC622 and NMC811, when the amount of cathode active material is relatively low in NMC111 cathode chemistry. Also, the positive effects of electric mobility are emphasized in vehicles with low fuel consumption and small batteries by conducting a simplified analysis of the use phase of battery electric vehicles running on different battery sizes and consumptions.