An Environmental Sustainability Analysis Tool for Next Generation Lithium Ion Batteries of Electric Vehicles

Abstract

Lithium-ion batteries (LIBs) are widely used in portable electronics and electric vehicles, but are limited in capacity and energy density. Tremendous efforts have been devoted to the research and development of next-generation LIBs with a high capacity and energy density, particularly through adoption of novel nano-structured materials in the LIB electrodes. The synthesis of nanomaterials, however, involves heavy use of toxic chemicals and nanoparticle emissions, which induce grave concerns on the environmental sustainability of next-generation LIBs. Silicon, with a high theoretical specific capacity, has been recognized as one of the most promising anode materials for next-generation LIBs. In this study, a comprehensive analysis tool is developed to evaluate the environmental sustainability of silicon-based LIBs for EVs by incorporating previously published data, and two nanostructured silicon materials, i.e., silicon nanowires (SiNWs) and silicon nanotubes (SiNTs) are chosen as examples. The purpose is to provide decision support for sustainable design of next-generation LIB technologies by providing overall environmental impact results and feedback to next-generation LIB designers to identify the tradeoffs between technical specifications and sustainability performance. Specifically, this tool based on an Excel spreadsheet comprises six modules, i.e., Dashboard, Material Consumptions, Gas and Aqueous Emissions, Nano Particle Emissions, Energy Consumption, and Life Cycle Impacts. The specifications of the battery packs are inputted in the Dashboard and the environmental impact assessment is conducted through the rest modules utilizing the inputted data to compute each modular results using the embedded formula from our previously published work. The conventional emissions and energy consumption data are characterized with the life cycle impact assessment method for design feedback, while the nanoparticle emission data are experimentally measured and directly used. This analysis tool provides insights into material consumptions and environmental impacts of SiNW-and SiNT-based LIBs and can be expanded for future analyses of other nanostructured next-generation LIB technologies for electric vehicles.