Meeting U.S. Light-Duty Vehicle Fleet Climate Targets under Battery Critical Material Supply Constraints

Electrified vehicles can substantially reduce emissions from light-duty vehicles (LDVs), but large-scale deployment remains challenging due to their associated demands for critical materials in batteries. The challenge is further complicated by trade-offs among greenhouse gas emissions, costs, and critical materials. We develop an optimization model to explore the cost and technical feasibility of meeting climate targets for U.S. LDVs under various material supply scenarios. To meet a sectoral target consistent with 2 °C, global lithium supply would need to grow by 35%/yr to 2035 or 50%/yr to 2030, assuming: (1) no recycling, (2) the U.S. can access a share of global supply proportionate to its population, and (3) medium- and heavy-duty vehicles electrify as fast as LDVs. Recycling or greater U.S. material allocation (proportionate to gross domestic product) can reduce the necessary growth rates to 30-45%/yr or 5-10%/yr, respectively. In low material supply scenarios, the 2 °C target is sometimes still attainable with preference to hybrid vehicles in the early years, later transitioning to a mix of fully electric and plug-in hybrid vehicles (PHEVs) from the 2030s onward. To hedge against future material supply uncertainty, PHEVs can act as transitional technologies in the short term and remain an important technology in the long term.