According to IDTechEx, electric vehicles (EVs) are a key route to reducing carbon emissions in the transport sector, however, the sustainability of materials used in EVs often comes under scrutiny, according to Dr. James Edmondson, research director at IDTechEx. IDTechExβs report, βElectric Motors for Electric Vehicles 2025-2035: Technologies, Materials, Markets, and Forecasts,β predicts the need for over 160 million electric motors per year by 2035.
In most cases, the materials used in the stator of electric motors in the EV market are similar, typically involving steel laminates and copper windings. The major difference lies in rotor materials, according to the report. Rare earth permanent magnet motors dominate the market, with IDTechEx reporting an 85% market share in electric cars for 2023.
Among materials considered for electric motors (steel, aluminum, copper), rare earths have the largest environmental impact per kilogram, considering factors like ozone depletion, global warming, acidification, eutrophication, and photochemical ozone creation, IDTechEx reports. Although they constitute a small portion of the motor (less than 1-2 kg), rare earth-containing motors tend to have a larger environmental impact per kW of power compared to rare earth-free alternatives. Magnet-free motors, however, may require more materials like copper and additional manufacturing steps that could increase energy consumption.
A more efficient motor reduces energy waste, meaning less electricity is drawn from the grid, which could significantly reduce CO2 output depending on the grid, IDTechEx reported. Moreover, an efficient motor allows for a smaller battery, reducing material use and the environmental impact of the battery system.
Power density is another consideration, IDTechEx said. A power-dense motor uses fewer materials to achieve the same power output. For example, an axial flux motor can achieve a power of 190 kW with less than 1.2 kg of magnets, or about 6.3 grams/kW, compared to a typical modern radial flux motor at around 10 grams/kW.
IDTechExβs research indicates that the average number of motors used per battery electric vehicle (BEV) in 2023 was 13% higher than in 2015, as more vehicles are equipped with dual, tri, and quad motor variants. More motors increase material utilization, not just for the motor but also for associated electronics and thermal management components.
The question arises: how many consumers need more than one motor? While it is a luxury, automakers often prefer selling higher-specification vehicles for better profit margins, IDTechEx said. This reduces the vehicleβs sustainability. However, if it encourages more people to purchase a BEV, it can be viewed as a positive step for the environment. IDTechEx believes that the availability of low-cost models, particularly in Europe, will likely involve single-motor solutions to keep costs down, thus boosting EV market growth.
As automakers strive to make more profitable EVs, the sustainability of EV components often takes a back seat to performance, efficiency, and price, IDTechEx said. Battery materials receive more scrutiny due to the quantities used compared to motors, as seen in early regulations like the battery passport in Europe, which mandates reporting the CO2 footprint of the battery. Initially, the sustainability focus will be on batteries, but motors could become significant in improving vehicle sustainability in the future, reports IDTechEx.
