Comparative Life Cycle Assessment of Silicon Nanowire and Silicon Nanotube Based Lithium Ion Batteries for Electric Vehicles

Abstract

Silicon nanowires (SiNWs) and silicon nanotubes (SiNTs), with high specific capacity and low volume expansion during charging and discharging processes, have been recognized among the most promising anode materials for use in next-generation lithium ion batteries (LIBs). However, the life cycle impacts of SiNW-and SiNT-based LIBs are of grave concern due to the heavy use of toxic chemicals and potential nanoparticle emissions during their manufacturing processes. In this study, life cycle assessment (LCA) method is adopted to evaluate the environmental impacts of two battery packs, which are configured with the same capacity of 63.5 kWh to power a mid-size electric vehicle (EV). Both battery packs are based on a lithium nickel manganese cobalt oxide (LiNi1/3Mn1/3Co1/3O2, NMC) cathode, but one uses a SiNW anode, whereas the other uses a SiNT anode (NMC-SiNW and NMC-SiNT). Following a cradle-to-gate approach, the analysis is conducted based on LCA databases and literature. Results indicate that to obtain the same capacity, the NMC-SiNW LIB battery is with higher material consumptions and environmental impacts than the NMC-SiNT LIB battery. This study provides insights into life cycle impacts of SiNW-and SiNT-based LIBs and can be useful for understanding and improving the environmental performance of nanostructured Si-based LIBs for next-generation EV applications.