Progress and Expectations for Zero-Emission Drivetrain Technology

Electric vehicles (EVs) have seen tremendous growth historically, but growth has slowed somewhat in 2024. Part of this slowdown is likely due to the lack of models in the more affordable price range (less than around US$25,000). With this in mind, the goal of automakers is to reduce the cost of making EVs, both to improve their profit margins on existing vehicles and to make lower-cost models more feasible. A greater variety of low-cost EVs will open another portion of the market and lead to reinvigorated growth.

 

IDTechEx's research covers key drivetrain technologies within EVs, including the battery, motor, power electronics, thermal management, and more. IDTechEx predicts the 2024 slowdown will be temporary, and strong growth will resume in the coming years as more models become available and further emissions regulations are implemented.

 

 

As the most expensive component of an EV, the battery presents the largest opportunity for cost reduction. To this end, we are seeing trends in battery chemistry to improve energy density (increasing range) and reduce costs.

 

The vast majority of the European and US markets use battery chemistries based on nickel and cobalt (e.g. nickel manganese cobalt/NMC, nickel cobalt aluminum/NCA). These chemistries present excellent energy density but contain expensive materials. Despite its lower energy density, its lower cost of materials has led to a resurgence in lithium iron phosphate (LFP), especially in the Chinese market. Tesla introduced LFP cells in its base version of the Model 3 in markets outside China, and other automakers look to be following suit.

 

 

Before the end of this decade, IDTechEx expects that there will be significant deployment of other cell chemistries. As a key example, LMFP (lithium manganese iron phosphate) fills the gap in price and energy density between LFP and NMC, providing another option for automakers. This is not to say that NMC is sitting still; there is increasing adoption of higher nickel variants, such as NMC 811 and NMC 9, to reduce reliance on cobalt and increase energy density even further. IDTechEx predicts that approximately 50% of the battery electric car market will use nickel-free chemistries by 2035.

 

 

Outside the battery cells, the battery pack also presents cost reduction opportunities. Chinese OEMs have pioneered cell-to-pack (CTP) battery systems where the normal modular structure is eliminated and cells are directly stacked together. This reduces materials, manufacturing complexity, and, ultimately, cost. This has been a major driver for BYD's adoption of LFP (where the cells have a lower energy density, but the improved energy density of the pack can offset this somewhat).

 

The next stage of battery-to-vehicle integration is cell-to-body (CTB) and cell-to-chassis (CTC), where the cells and their packaging become a structurally integral part of the vehicle. This has also made it to market with BYD and Tesla's 4680 pack, as well as some other players. IDTechEx's research found that approximately 22% of EVs sold in 2023 were using either a CTP or CTB design, with the majority of this in China. Many OEMs in Europe have also announced CTP designs, and in the coming years, IDTechEx predicts market penetration will continue.

 

 

The electric motor is another key area of innovation. A more efficient motor means less of the battery's energy is wasted, and the EV's range can be increased, or a smaller battery can be used for the same range (reducing battery costs). There are also considerations around the materials used.

 

The permanent magnet (PM) motor is the staple of the EV market due to its exceptional power density, efficiency, and ease of manufacture. However, the magnets contain rare-earths, which, despite their name are relatively abundant, but have a very constrained supply chain leading them to be expensive and subject to significant historic price volatility.

 

There has been increased interest in rare-earth-free motors. In Europe, the key approach from automakers like Renault and BMW has been the wound rotor motor, where permanent magnet materials are replaced with copper windings as electromagnets. Whilst this reduces the bill of materials, these motors require more manufacturing steps, require a method of exciting the rotor windings, and are typically larger and heavier than their PM counterparts. However, significant developments have been made by both automakers and tier 1 suppliers to make these motors more compact and competitive with PM motors.

 

Another alternative is to change the permanent magnet materials. There are various alternatives, such as AlNiCo, SmCo, and ferrite magnets. Still, none of these can provide the combined magnetic performance (maximum energy product, coercivity, and remanence) of rare-earth magnets. However, companies such as Niron Magnetics push the performance of materials to close the performance gap. In a lower-cost EV model, ultimate performance might not be needed; instead, a lower power density motor utilizing rare-earth-free magnets could be used, which would suit this target market.

 

 

The prices of rare-earth materials have settled again after a recent high in 2021/2022. Whilst this is the case, OEMs are more likely to remain with PM motors, but the uncertainty around future supply and the potential for material cost reduction has contributed to IDTechEx's prediction that up to 30% of the electric car market will be using rare-earth free motor technologies by 2035.

 

 

In ICE vehicles, only 20% of the energy from fuel drives the vehicle. Contrastingly, EV powertrains are much more efficient, with approximately 90% of the energy going into an EV propelling the vehicle. One key area where EVs can further increase their efficiency is in the power electronics.

 

 

Silicon carbide (SiC) MOSFETs have entered the mainstream market, led by Tesla and Hyundai. Power switching is the fundamental principle behind all power electronics: by switching transistors at kHz frequencies, one can modulate between different forms of electricity: AC to DC, or high voltage to low voltage. For example, the traction inverter takes DC from the high-voltage battery and converts it to AC to drive the electric motor. The 'wide bandgap' of SiC can decrease switching losses by 70% compared to Si, yielding increased efficiency with a reduction in dissipated heat, all on a smaller die. Switching from Si IGBTs to SiC MOSFETs can extend vehicle range by ~7%.

 

These advantages also unlock 800V architectures in EV powertrains (where Si IGBTs are especially inefficient), a development that will increase charging power by 40%, and possibly more. For electric trucks, MW charging powers are possible at even higher voltages. With leading and emerging OEMs alike, such as BYD, Volkswagen, and Lucid all committing to SiC MOSFETs, IDTechEx expects 800V EVs and SiC MOSFETs to become commonplace in the passenger vehicle market over the next ten years.

 

Gallium nitride (GaN) in recent years has come to dominate the consumer electronics market, but it has not been implemented in EV power electronics due to it being unable to handle the high voltages (400V+) and powers (10kW+) required. With players across the supply chain contributing to competition, maturity, and new technologies, IDTechEx expects GaN to enter the EV power electronics market from 2025-2027, depending on the application, to be competitive with Si and SiC by 2035. When used to its fullest potential, GaN can achieve greater power conversion efficiencies than SiC, but this will depend on new technologies concerning substrates, thermal management, and vertical GaN transistors.

 

 

 

IDTechEx predicts that BEVs will be the dominant zero-emission transport solution, but that does not mean that they will be the only solution. There are lots of scenarios where duty cycles are difficult to achieve with a BEV, and hence alternatives are available.

 

 

The internal combustion engine (ICE) has been the workhouse of the automotive world for well over a century, but the rise of cleaner, greener, and more efficient EVs has led many to believe that the age of ICE is drawing to a close. However, the persistent challenges of electrification have led some to search for a way to keep combustion alive, and many proponents of hydrogen internal combustion engines (H2ICE) believe they may have found a way to do just that.

 

H2ICE is a fundamentally different decarbonization approach that seeks to retain existing technologies but runs on a carbon-neutral fuel, hydrogen. Hydrogen engines can be adapted with relative ease from diesel/petrol engines, so the appeal for legacy ICE OEMs is clear: keeping the same mature ICE technology but also leveraging existing production capabilities and supply chains to produce carbon-neutral vehicles rather than relying on entirely new and underdeveloped battery production capacity.

 

Although hydrogen is a carbon-neutral fuel, the high temperatures at which it combusts can lead to nitrogen oxides (NOx) being formed and released into the atmosphere. As NOx is a damaging pollutant and greenhouse gas (GHG), if left untreated, it negates the emissions-free credentials of H2ICE. However, by leveraging existing diesel after treatments and running at a very lean engine burn, the NOx emissions can largely be avoided, potentially allowing H2ICE to be considered an ultra-low emissions drivetrain, but not quite zero-emissions.

 

 

The greatest challenge for H2ICE is the fuel itself. Hydrogen is very energetically dense per unit weight but contains a very low amount of energy per unit volume. A meaningful vehicle range requires large tanks even when compressed to pressures hundreds of times greater than atmospheric. This is where H2ICE suffers a major drawback against the other type of hydrogen mobility, fuel-cell electric vehicles (FCEVs). The tank-to-wheel drivetrain efficiencies of H2ICE are much lower than FCEVs, meaning that even more fuel storage space is required in a combustion-powered hydrogen vehicle than a fuel cell-powered one. Even when hydrogen is cooled to its liquid form, increasing its density, it still has a large space claim. This barrier means H2ICE is unlikely to make any serious inroads in the passenger car market, which is increasingly turning electric.

 

 

However, IDTechEx assesses that the short-term economic benefits of H2ICE (lower vehicle CAPEX) give the technology promise in hard-to-electrify sectors, particularly heavy-duty trucking, where the required ranges necessitate expensive and heavy Li-ion batteries. In contrast, the size of the vehicle makes adding additional hydrogen tanks less of a challenge than in a car. IDTechEx expects H2ICE to be a transitionary technology, as battery and fuel cell improvements will drive the adoption towards these higher-efficiency solutions in the long-term.

 

 

Whilst FCEVs are a more efficient and commercially available method of hydrogen powered transport, they have continued to struggle with adoption in the passenger car market, but present some promise in commercial vehicle sectors.

 

In 2022, global sales of fuel cell cars plateaued, and in 2023, they decreased by nearly 45%. BEVs continue to improve in technology and are largely suitable to cover most potential consumers' drive cycles, especially as charging infrastructure improves. Hydrogen refuelling infrastructure deployment has also plateaued and is much less available than charging. Combine that with the high price of hydrogen at the pump, and it makes a hard case for adoption in passenger cars.

 

IDTechEx predicts that FCEVs will only make a significant impact in heavy duty vehicle segments, but only for hard-to-electrify duty cycles in harsh climates with long ranges. Even then, IDTechEx predicts that BEVs will be the dominant zero emission technology across all road vehicle segments. Several regions are pushing for a strong hydrogen economy; if they can realize improved infrastructure and bring down the cost of green hydrogen, then it may become a more viable zero emission solution in those regions.

 

IDTechEx's EV research analyses and benchmarks drivetrain technologies and materials such as batteries, motors, power electronics, thermal management, and fire protection. IDTechEx also presents market analysis of various vehicle segments, including cars, vans, trucks, buses, boats, ships, micromobility, trains, aircraft, and more. Please see IDTechEx's full EV research portfolio at www.IDTechEx.com/Research/EV.

This article is from "Technology Innovations Outlook 2025-2035", a free collection of insights from industry experts highlighting key technology innovation trends shaping the next decade. You can download the full collection here.

IDTechEx provides trusted independent research on emerging technologies and their markets. Since 1999, we have been helping our clients to understand new technologies, their supply chains, market requirements, opportunities and forecasts. For more information, contact research@IDTechEx.com or visit www.IDTechEx.com.