Rare earths are a group of elements whose availability has been of concern due to monopolistic supply conditions and environmentally unsustainable mining practices. To evaluate the risks of rare earths availability to automakers, a first step is to determine raw material content and value in vehicles. This task is challenging because rare earth elements are used in small quantities, in a large number of components, and by suppliers far upstream in the supply chain.
For this work, data on rare earth content reported by vehicle parts suppliers was assessed to estimate the rare earth usage of a typical conventional gasoline engine midsize sedan and a full hybrid sedan. Parts were selected from a large set of reported parts to build a hypothetical typical mid-size sedan. Estimates of rare earth content for vehicles with alternative powertrain and battery technologies were made based on the available parts' data.
We estimate that approximately 0.44 kg of rare earths are used in a typical conventional sedan, with approximately 80% of the rare earth content in magnets. As such, neodymium is the most extensively used rare earth, followed by cerium, which is used mainly in catalytic converters. The mass of rare earths in a full hybrid electric vehicle with a nickel metal hydride battery is approximately 4.5 kg. A full hybrid electric vehicle with a lithium-ion battery contains approximately 1 kg of rare earth elements. Future plug-in hybrid electric and battery electric vehicles are expected to be equipped with lithium-ion batteries and have rare earth contents that still need to be evaluated.
