Comparative life cycle assessment of lithium-ion batteries with lithium metal, silicon nanowire, and graphite anodes

Lithium metal and silicon nanowires, with higher specific capacity than graphite, are the most promising alternative advanced anode materials for use in next-generation batteries. By comparing three batteries designed, respectively, with a lithium metal anode, a silicon nanowire anode, and a graphite anode, the authors strive to analyse the life cycle of different negative electrodes with different specific capacities and compare their cradle-to-gate environmental impacts. This paper finds that a higher specific capacity of the negative material causes lower environmental impact of the same battery. The battery with a lithium metal anode has a lower environmental impact than the battery with a graphite anode. Surprisingly, although the silicon nanowire anode has a higher specific energy than graphite, the production of a battery with silicon nanowires causes a higher environmental impact than the production of a battery with graphite. In fact, the high specific energy of silicon nanowires can decrease the environmental impact of a battery with silicon nanowires, but silicon nanowire preparation causes extremely high emissions. Therefore, batteries with lithium metal anodes are the most environmentally friendly lithium-ion batteries. Batteries with lithium metal anodes could be the next generation of environmentally friendly batteries for electric vehicles.