Lexus has premiered the Lexus LFA Concept, a battery electric vehicle (BEV) sports car concept model, developed alongside Toyota Gazoo Racing’s GR GT and GR GT3. Following the legacy of the Toyota 2000GT and Lexus LFA, it embodies the spirit of Shikinen Sengu – the passing on, and evolution, of techniques from veteran craftsmen to the next generation.

Shared aspirations behind GR GT and GR GT3

The Lexus LFA Concept is a next-generation sports car concept model that embodies, along with the GR GT and GR GT3, Toyota’s Shikinen Sengu. Centered on the three key elements of a low center of gravity, low weight with high rigidity and the pursuit of aerodynamic performance, it shares the techniques and skills used in developing the GR GT and GR GT3 while exploring the potential that is unique to BEVs.

Starting with elements such as a light, high-rigidity all-aluminum body frame and an ideal driving position that enhances a sense of car-driver unity and vehicle handling, Lexus has given form to a sports car fit for the electrification era, with a desire to deliver driving pleasure and demonstrate the potential of BEV sports cars. Its pursuit of optimal BEV packaging has resulted in a fusion of high-level driving performance, which stems from the GR GT and GR GT3, and styling of timeless value that should prevail well into the next generation.

The LFA name represents a vehicle embodying technologies that the engineers of its time aim to preserve and pass on. The Lexus LFA Concept continues this legacy, reflecting Lexus’ commitment to retaining and evolving the knowledge and values of sports car craftsmanship for future generations.

The car draws on the design of the Lexus LFA while focusing on a balanced, enduring style. Built on the all-aluminum GR GT body frame, it is designed for sports car performance. Its low, flowing silhouette combines classic coupe proportions with sculptural lines, creating a sports car with broad aesthetic appeal.

Immersive cockpit

Featuring the same driving position as the GR GT and GR GT3, the immersive cockpit aims to enhance the sense of car-driver unity to deliver unprecedented driving pleasure.

The interior is designed with simplicity, focusing on refined functional components around the driver to create a sense of exhilaration. The steering wheel is tailored for sports car use, with controls arranged for intuitive operation without regripping or looking. Combining minimalist design with mechanical appeal, the cabin aims to offer a uniquely immersive driving experience.

In related news, Toyota Gazoo Racing unveils GR GT and GR GT3

South Korean automotive manufacturer KGM (formerly SsangYong) and Phinia Delphi France are to jointly develop hydrogen engines. The collaboration was confirmed last month at KGM’s R+D center in Pyeongtaek, South Korea.

KGM is currently involved in a national project led by South Korea’s Ministry of Trade, Industry, and Energy. This initiative promotes low-carbon technologies and practices to cut greenhouse gas emissions and support the country’s transition to a carbon-neutral economy. Primarily it aims to develop a 2-liter diesel-based hydrogen engine and vehicle that meets NOx emission regulations and achieves a driving range of over 500km, making it suitable for both industrial and vehicular applications.

The main goal is to combine KGM’s in-house diesel engine technology with Phinia’s fuel injection system and ECU technology. Together the two companies will design a multi-purpose engine and vehicle, and create the foundation for an extended-range electric vehicle, while also conducting ongoing research and development.

A KGM representative said, “Eco-friendly hydrogen engines are a crucial next-generation powertrain technology. The hydrogen engine developed through this collaboration will be applicable not only to vehicles but also to construction and industrial machinery.”

The company has also confirmed the launch of plug-in hybrid technologies, within its existing range, throughout 2025.

Automotive and e-mobility supplier BorgWarner has secured a contract to supply its high-voltage eFan system for a major OEM’s series of heavy- and medium-duty battery electric vehicles (BEVs) in North America.

The eFan system includes a fan, an e-motor and an integrated high-voltage inverter, capable of delivering up to 10kW of power and 40Nm of torque. The system is built to handle a range of operating temperatures, from -40°C to 80°C. The system’s components are also liquid-cooled.

In addition to its power capabilities, BorgWarner says the eFan system is engineered for optimal noise, vibration and harshness (NVH) performance, utilizing a fan geometry designed for full performance at speeds below 3,000rpm.

Dr Volker Weng, vice president of BorgWarner, and president and GM of turbos and thermal technologies, said, “Our sophisticated and efficient eFan system has the scalability to meet specific customer requirements, with a wide voltage range and liquid-cooling for long-term reliability. I’m proud of our team for growing our relationship with this global OEM by winning this business and providing yet another solution that enables a more sustainable future.”

With production set to begin in the fourth quarter of 2027, BorgWarner’s eFan technology supports a voltage range of 550V to 850V. Solutions for different heavy-duty commercial vehicle applications are also considered, including BEVs and fuel-cell electric vehicles, with high-power segment applications capable of up to 40kW and 160Nm.

One area where all current manufacturers seem to take their own direction is the structural design of battery packs. These range from traditional fabricated, stamped steel structures, through to advanced aluminum and composite productions. The pack structure and the way in which the various modules and other ancillaries such as cooling systems are arranged can have a significant impact on the weight, size and cost of a pack.

At one extreme, there is GM’s Hummer EV, which features a behemoth 200kWh pack weighing in at over 1,000kg. Of course, a large element of this weight is the sheer number of cells needed to hit the required energy, but the rest of the pack is no featherweight. The structure is fabricated from steel pressings, welded and secured with fasteners (257 in total) – there is no use of aluminum in the double-decked design. Impressively, even the coolant hoses feature an outer, reinforced braided sleeve inside the pack.

At the other end of the spectrum, there are packs such as those found in Lucid’s Air. Here, the pack structure is predominantly formed from bonded and welded aluminum extrusions, with a composite under tray (which also doubles as an underbody aerodynamic device). The overall result is a structurally robust yet relatively lightweight structure.

Notably, Lucid has also excelled with the packaging of its modules and other ancillaries, as reflected in the volumetric energy density of its pack, which comes in at 375Wh/l – impressive when compared with the next best on the market, Tesla’s Model S Plaid, which hits approximately 275Wh/l. It should be noted that the Tesla does have a superior energy density over the Lucid.  Most battery packs in vehicles currently on the market are traditional in the sense that they use individual modules within the pack, with surrounding support structures and the pack split into bays dividing blocks of modules.

However, moving up an integration notch, and as displayed by Chinese manufacturer BYD among others, is the use of CTP constructions, which eliminates the modules and also packs more cells into a given volume. Depending on how this approach is executed, CTP relies on the cells to provide structure, though the line can be blurred as to whether such packs count as cell to chassis/vehicle construction.

As noted, 46mm format cells lend themselves to use in such structural packs and Tesla has deployed these in the CTP design used in the latest Model Y. Pouch cells are not really suitable for CTP designs, but prismatic cells can be used, as evidenced in BYD’s CTP ‘Blade’ design.  The next logical step is the introduction of true cell to body packs whereby the pack not only contributes to the structure of a chassis, but almost entirely replaces the lower chassis structure.

Again, BYD has been at the forefront of such developments, and its e-platform 3.0 features an evolution of the Blade concept that sees the cells tightly integrated into the battery housing.   The realization of structural batteries has required a host of developments, not least in terms of adhesive solutions to secure the individual cells, thermal interface materials and cooling concepts.

A common feature of packs such as BYD’s is also the use of LFP chemistries, which, despite having a lower energy density than lithium-ion, are more stable and can therefore be packaged more tightly with fewer concerns about propagation of thermal events. It should be noted that Tesla’s 4680 cells used in the Model Y pack use a lithium-ion chemistry.

Beyond these current trends, there are developments underway looking to push the structural role of batteries even further. For example, there is considerable research into laminated composite batteries,1 where carbon fibers are used as structural electrodes alongside a structural electrolyte, removing the need for individual metallic housings for cells.  These batteries are still a long way from commercial reality; however, the greater use of composites within packs does offer potential for useful weight savings. This brings with it a host of associated challenges, though, not least reliably simulating composite material behavior, particularly in crash situations.

Finally, it is worth touching upon the other ancillary parts found in a pack and their contribution to pack mass and volume. For example, the use of aluminum bus bars is becoming more commonplace, thanks to their low weight and cost. However, their cross-sectional area needs to be around 50% greater than copper for a given current carrying capacity.  The termination of aluminum bus bars also needs close attention because of the effect of thermal cycling on fastener integrity, due to aluminum’s greater coefficient of thermal expansion (compared with copper).

Tesla, for example, welds copper terminations onto its bus bars to negate this issue, while Lucid uses only aluminum, potentially made possible thanks to the lower ohmic heating of the bars due to its 800V system architecture.  Approaches to venting of packs in the event of thermal runaway also see considerable variation across the industry.

Many manufacturers incorporate vents into the sides of packs, oriented to each module, but Hyundai’s E-GMP platform uses the seal between the pack cover and frame as a failure point in the event of pressure build-up. The ribbed seal that runs around the perimeter of the pack has compression-limiting inserts to ensure sufficient clamping to provide an environmental seal, but not so tight that gas cannot escape from inside.  The downside is a more time-consuming manufacturing process than for a liquid applied sealant, but with the benefit of fewer machining processes and components needed to incorporate vents elsewhere within the structure of the battery pack.

Cooling strategies can have a significant impact not only on the operation of a battery pack, but also on the manufacturability. Balancing an effective cooling system, which ensures even temperature distribution across cells, against the cost of complexity can be approached in a variety of ways.

As with pack construction, every manufacturer has their own unique take. Looking at the very high-performance end of the market, Lucid uses a cold plate design that sits atop the cylindrical cells in each of its modules, with the current collector fingers located on the bottom of each module (the tops of the cells are oriented downward so that if they vent, this is directed away from the passenger cabin). The cold plates feature dimples to increase surface area and are supplied with a water-glycol cooling mix from a central cooling supply that runs up the center of the pack. The cells in Lucid’s modules are not potted; block of cells are split by dividers to deliver a degree of compartmentalization. Contrast this with Tesla’s approach on the Model S and others, which use a side cooling approach. For the ultimate in performance, top and side cooling can be deployed, as is the case with Rimac’s pack design in the Nevera, which has top and bottom cooling plates.

One cooling solution that is particularly worthy of note from a manufacturability perspective is that developed by Hyundai for its E-GMP (Electric Global Modular Platform), which uses a single large cold plate to form the bottom of its battery pack, rather than individual module level plates. This has a number of benefits: it reduces the number of processes needed for manufacture of the pack while also placing all of the cooling connections external to the pack, which not only aids serviceability but also practically eliminates the possibility of internal coolant leaks. VW’s MEB (modular electric drive matrix) platform takes a similar approach.

Immersion time
Direct or immersion liquid cooling1 is one area of particular interest for high-performance battery applications. Although it does introduce considerable complexity into the construction of a pack, it is exceptionally effective for heat removal.

There are plenty of immersion-cooled battery systems in development. For example, UK-based Sprint Power is looking to commercialize a modular battery concept that places a 5kWh pack, complete with BMS, immersion cooling and integrated pump within a single housing. Capable of a peak discharge rate of 230kW over five seconds, or 105kW continuously, the pack is aimed at use in hybrid vehicles. The high C-rate is achieved through the use of both immersion cooling and very high power cells from another UK company, AMTE Power. According to the company, the pouch cells are capable of 35C continuous discharge. Notably, Sprint Power has been working closely with Castrol, the brand of BP responsible for lubricant and coolant development, on immersion cooling fluids for EV applications.

1) Roe C, Feng X, White G, Li R, Wang H, Rui X, Li C, Zhang F, Null V, Parkes M, Patel Y, Wang Y, Wang H, Ouyang M, Offer G & Wu B (2022), Immersion cooling for lithium-ion batteries – a review. Journal of Power Sources

Recent years have brought into harsh focus how fragile automotive supply chains can be. Spanning the globe, seemingly unrelated geopolitical events can have a huge impact on the availability of key components, placing the industry’s just-in-time production models in peril. Although semiconductors have recently taken the limelight, the reliance of most high-performance automotive traction motors on rare earth magnets has also come under scrutiny. Not only are the materials themselves subject to supply constraints but there is also an increasingly vocal conversation underway regarding their sustainability from both an environmental and a social responsibility angle.

The result is a growing requirement for power-dense motors that forgo such magnets. This is what was behind UK-based Ricardo’s development of the Alumotor concept, which not only does away with rare earths but also minimizes the use of copper. Ricardo’s project scope also includes industrial concepts for the motor and its integration into an EDU. APTI spoke to the company’s automotive and industrial technical authority head, Dr Jay Al-Tayie, and Simon Meredith, PEMD and transmission project engineer for performance products, to find out more about this novel motor architecture.

“The project started three years ago, when we were looking for a sustainable motor solution for the UK market,” says Al-Tayie. Permanent magnet motors are hard to beat from a performance and efficiency perspective “but they are expensive, not very sustainable and sensitive to supply chain issues,” he adds.

Making a rare-earth-free motor that comes close to the power density of PMSMs was going to be a tough undertaking, but Ricardo’s solution blends existing technology and novel engineering to achieve just that.

The Alumotor is a synchronous reluctance machine, a layout chosen for its potential for excellent torque output. “With switched reluctance machines, you obviously have to switch the phases, which is why they are noisy from both an audible and efficiency perspective,” explains Al-Tayie. “At low speed they are also quite hard to control and not very efficient. A synchronous reluctance machine is controlled very differently. You can run it very much like a normal permanent magnet machine, you don’t need rare earth elements or copper windings and, importantly, it is very robust. There is nothing really to degrade over time, unlike a PM machine where you may lose performance due to thermal and coercivity impacts.”

It is this robustness that means the Alumotor can be run at higher temperatures. With just steel and aluminum in the construction, there is nothing to be affected by heat (within reason). The only specific consideration is the insulation material coating the windings, but solutions are available. “As long as you select the right material, it is fine,” explains Al-Tayie. “Most motors do not go beyond 180°C and use class-H insulation, but you can go to class C, which is 220°C or higher. The advantage is you can run the machine hotter and increase power density without upping the size.” Furthermore, the Alumotor is designed to run at 800V, which means lower current and thus reduced losses. “Again, this lets you increase the power density,” he adds.

One of the standout features, and giving the motor its name, is the use of aluminum windings. “People ask, why aluminum? Because it’s more sustainable than copper, it’s cheaper and more readily available. With the technology we have developed we are able to use it without compromising power density, running at higher voltages and higher temperatures, for example,” says Al-Tayie.

Another novel feature of the design, beyond the use of aluminum, is the rotor topology and the form of the flux guides that direct the magnetic flux. “They are voids, just air,” says Al-Tayie. However, Ricardo also has a variant in development where these voids are filled with magnetic material. For machines that require lower power densities (but higher than the standard Alumotor), these could be ferrite magnets. Ricardo is working with partners on the development of materials with the same flux density as rare earth magnets but made from sustainable materials. This development would make the Alumotor design comparable to the best high-performance machines on the market.

The final piece in the Alumotor puzzle is the cooling system, which ensures that coolant can be placed directly where the greatest heat is generated. Both the rotor and the stator feature cooling channels, while spray jets also ensure the (dielectric) coolant can be directed onto the windings. “We are hitting it from every angle,” says Meredith. “We have conducted a lot of computational fluid dynamics and analysis work, which has given us a lot of cooling opportunities for the rotor and stator and means we can run them as hard as possible.”

Partner optimization
The Alumotor was developed as a joint effort by the UK-Alumotor consortium, led by Ricardo and involving partners Aspire Engineering, Brandauer, Warwick Manufacturing Group at the University of Warwick, Phoenix Scientific Industries and Global Technologies Racing (GTR). The breadth of expertise across the consortium has been a key enabler for the project. For example, Meredith highlights the work done in conjunction with Brandauer, which manufactures the steel laminations: “We’ve done a lot of technical work to make sure that the rotor is structurally sound and not going to break apart under its own stresses. These have been really delicately and intricately worked out and there has been a lot of collaboration with Brandauer on the stamping to make sure they can actually be manufactured. It’s been really good working with the consortium, to have those experts that you can lean on to understand what we can and can’t do and how feasible it is to manufacture things.”

There are some manufacturing differences compared with a regular motor using copper windings. For example, the aluminum is softer and displays a greater level of spring-back when the hairpins are formed, but this can be accommodated within existing process technologies. “There has been a lot of careful experimentation to work out the parameters, such as making sure the bends are made in such a way as to not crack the enamel insulation,” notes Meredith. The welding of the windings also needs a different approach from copper, but again, there are established processes that can be adapted.

Full-circle approach
Early prototypes proved the concept and in 2022 Ricardo, in conjunction with its partners, commenced development of the current iteration of Alumotor, with support from Innovate UK’s Driving the Electric Revolution challenge fund, encompassing both the actual motor design and the supporting supply chain.

Ricardo is not immediately targeting the passenger car market with the Alumotor. Instead, it is looking to the LCV and off-highway markets, which would benefit most from its affordable and rugged characteristics. “While everyone is electrifying and everyone is going after copper and rare earth magnets, this is a great opportunity for an OEM customer to diversify and not get hit by the price rises that there are going to be,” concludes Meredith.

Further information about Ricardo’s electric vehicle solutions can be found here

Sustainable liquid fuels are clearly going to be a vital element in the decarbonization of transportation, in automotive and in other sectors such as aviation and marine. While electrification will account for part of the vehicle fleet, there will still be hard-to-electrify, high-energy-density applications and a legacy fleet of ICE vehicles in operation for several decades.

The development of such fuels is gathering pace. At the forefront of the creation of truly ‘drop-in’ solutions is Haltermann Carless, an HCS Group company with over 160 years’ experience in the hydrocarbon industry. “As a group, we want to go fossil-free,” says Alessandro Ferrari, head of development of performance fuels at Haltermann Carless. The company is not solely an automotive fuel supplier; for example, it is the first German company to pursue the development of a sustainable aviation fuel (SAF) production plant and has signed an agreement for the supply of SAF to Lufthansa. Furthermore, the chemical company is also heavily involved in the production of sustainable industrial solvents and other renewable chemicals.

HCS Group recognizes that the global energy requirements for transportation will be diverse. “We believe that global sustainable mobility is a mix of different solutions,” Ferrari explains. “Fossil-free liquid fuels will play a fundamental role to reduce the greenhouse gas emissions of the existing fleet, and also the next generation of ICEs.” This final point is an important one. ICEs will continue to be produced for the foreseeable future and their efficiency will increase. “Part of that means moving to higher compression ratios, pre-chamber spark plug, lean combustion, which in turn needs fuels with greater knock resistance.”

Relatively speaking, it is still early days for the sustainable fuels industry, but development is moving at pace. Ferrari highlights several of the key challenges. “For the maximum greenhouse gas (GHG) reduction, you of course want 100% fossil-free fuel. But at the same time, that fuel still needs to be compliant with regulations and its price must remain viable, balancing between performance and cost.” He points out that currently, because of the relatively small volumes of fuel in production, the cost of feedstocks remains high. “Because it is a niche product, you don’t have those economies of scale yet.”

Then there are the ICE-specific challenges to address. “The fuel must be compatible with all the engine parts, fuel lines, tanks and other components, which is also a warranty matter for vehicle manufacturers. Then one has the combustion performance, not just the efficiency but also the emissions, which are not only CO2. We aim for clean combustion, low emissions and a drop-in solution.”

An accusation often leveled at synthetic fuels and biofuels is that they are an inefficient use of renewable energy. However, the areas around the world where there is the greatest potential to generate low-cost renewable energy are not necessarily where it is most needed. Synthetic fuels are an ideal medium through which to distribute this energy.

Ferrari also highlights that fuels can be decarbonized at every stage of the production process. “The tank-to-wheel emissions of renewable fuels can be considered neutral because for producing these fuels, the amount of CO2 emitted at the tailpipe has been originally captured both for synthetic and biofuels.” He also noted that, “The well-to-wheel greenhouse gas emissions using biofuels today is reduced by around 72-75% versus fossil fuels, as the biomass itself is a carbon capturing system. By using renewable energy for the synthetic fuels, more than 92% well-to-wheel GHG reduction can be achieved.”

Performance development
Mainstream bio and synthetic fuel supplies are still limited in many markets. For example, the UK only has 10% renewable blends on general sale. However, in motorsport, the uptake of sustainable fuels has been enthusiastic. The last five years have seen multiple high-profile race series adopt sustainable fuels, and HCS Group, via its ETS Racing Fuels brand, is heavily involved in the supply of fuels for competition and classic vehicles.

The acceleration in the adoption of these sustainable fuels has impressed Ferrari. “In 2021, it started with the WTCR [World Touring Car Cup] mandating 15% renewable content in its fuels, then the next year you had the WRC [World Rally Championship] pushing straight to 100%, complete with hybrid systems,” he says. “You have to acknowledge the role of the FIA in this situation, having the guts to say, ‘Let’s try another way,’ and going to 100% renewable fuels.” Other series have followed suit, including the World Endurance Championship (100% biofuel) and F1 steadily upping the renewable content of its fuels, targeting 100% in 2026.

This is why motorsport is such a vital proving ground, giving brands such as Haltermann Carless and ETS Racing Fuels a sandbox in which they can develop fuels hand in hand with some of the latest advances in ICE technology. “It is still an evolution, and the next-generation fuels we are working on are looking to improve their properties,” says Ferrari. “For example, removing some of the components that are particularly heavy in the cut of gasoline while also improving the evaporation patterns. You could also use ICE hardware modification to approach this, but that is not the point of a drop-in fuel. We want to have the fuels working in every vehicle and with every technology.

“In the past and still today, the easiest way to make bio or sustainable fuels is to have high alcohol content. The problem is that these fuels are not drop-in. Now, we have blends of hydrocarbons, and that leads you toward much more of a drop-in fuel. There is still plenty to do, like with the knock resistance, evaporation and the suitability of the fuels for use with direct injection.”

Moving beyond fuels, he points out that there are benefits to be had from removing fossil content from other hydrocarbon-based fluids, including lubricants. “That will go together with fuel and engine development. There are still a lot of engines to be developed in the future and development of new fuels and lubricants will be needed for those.”

Ferrari is of the opinion that the market is already there for increased production of fossil-free fuels. However, “Regulations globally need to catch up and encourage their widespread adoption, also by providing investment security. Fortunately, the trend seems to be toward this.”

It will then be up to companies such as HCS Group to ensure they are ready for the market opening up. “We strongly believe we have the capabilities and tools, and the rightcompany size, to be able to find the market synergies in an intelligent way, how to use the hydrocarbon streams, defossilize them and create that future readiness in the market,” concludes Ferrari.

More information on Halterman Carless fuels can be found here

APTI visits GM’s Global Technical Center in Michigan to get to know the company’s new Ultium battery tech and how it plans to use it.

General Motors has been producing electrified vehicles for several years, but its new Ultium architecture introduces the OEM’s third-generation BEV3 batteries and a more scalable solution. APTI discusses the new platform with Tim Grewe, GM’s director of electrification strategy and cell engineering.

Ultium has been optimized for crossovers and SUVs but can also be used in pickup trucks and is future-ready to be used in autonomous vehicles as GM heads toward its stated corporate goals of zero crashes, zero emissions and zero congestion.

The building blocks of Ultium are the battery cells, developed jointly by GM and LG. They are large-format pouch cells, 580mm long and 115mm tall, dimensions defined by manufacturing capability optimization. They run across the width of a vehicle and can be fitted into anything from a Cadillac Lyriq to a Chevrolet Blazer or the Hummer EV. The cells can also be placed horizontally 60mm or 80mm apart, which enables them to be placed under the rear passenger footwell in a performance sedan.

Taking the Lyriq as an example, Grewe says there are 288 cells under the floor providing 104kWh of usable energy under the EPA test cycle. High-energy-density electrodes provide around 620Wh per liter at a cell level. The key differentiator, says Grewe, is the cathode chemistry: “Some people use a nickel cobalt aluminum chemistry, some use a nickel cobalt manganese; we use nickel cobalt manganese and aluminum.

“With that, we get very good cycle life. At high temperature we hold cycle life better, the cathode does not degrade as much. Resistance to micro cracking and having to reform barriers inside the cell is the best and so if you look at our Bolt 2016 it was cobalt manganese. We took the cobalt down by 70% because of the high-cost nature of it and the environmental, social and governance issues with cobalt. We reduced the cost by 40% compared with the Bolt EV.”

However, Grewe won’t divulge the exact make-up of the materials, acknowledging that this is a very competitive area of the auto industry where everyone likes to keep things secret. But he is more than happy to discuss the anode and cathode engineering.

Anode innovation
The anode is made from artificial graphite carbon, which is common across the industry. However, Grewe says that because it takes six carbon elements to hold one lithium ion, future development will see the mixing of carbon with silicon, as one element of silicon can hold one lithium ion. Yet, because silicon expands more than graphite, Grewe says the team decided to use a uniform electrode rather than a wound one in order for Ultium to be future-ready for a change in the composition.

“Today a wound electrode works, it’s in the industry, but for future expanding technology – silicon, lithium metal technology – which expands a lot more, we’re investing now in the uniform electrodes to be able to take that expansion while maintaining life. That was one of our fundamental strategies,” Grewe explains.

The cells themselves are grouped in a cell module assembly (CMA) in batches of 24 to create a serviceable unit, with each module providing around 9kWh. The bulk of the pack assembly is done by robots that stack the cells, form the leads, weld them together and insert them. Welded connections require less space and provide lower resistance and thus reduced heat rejection, according to Grewe. This is not common practice though, with most top terminal cells being bolted in, although he expects that most companies will switch to welding once they get to full volume production and they have the requisite welding technology.

Service considerations
The packs are engineered to be serviceable at a GM dealership level, where the lid can be removed and a CMA replaced if necessary. Each has its own QR code so material content and history can be checked. This also helps for future recycling needs.

The packs also incorporate the necessary monitoring and balancing electronics, as well as the thermal management components, all of which communicate wirelessly with the vehicle.

This creates a mesh network in the vehicle that reduces wiring by around 90%, which GM sees as a big advantage in reducing potential failure points. It also assists with over-the-air updates and moving more of the vehicle computing away from the vehicle itself and into the cloud.

“We’re no longer limited to the on-vehicle computing capability and knowledge; we also put it up into the cloud and we add that into the Ultium,” explains Grewe. “With that we really think that we can meet all of our customers’ needs with a lot less proliferation, and we can be much more agile as the customers change their preferences into new technology. We think Ultium is a very good solution now, but we do plan to upgrade it for the future and [thanks to the] architecture we are going to be able to do those upgrades with minimal disruption in a continuous fashion.”

The battery packs themselves can also be scaled. There is a single 12-module pack on the Lyriq, while on the Hummer EV one pack is placed on top of another. It’s also possible to switch to a pack containing 10, 8 or 6 modules for smaller models, but Grewe says these would be future products that are not currently planned – or rather, cannot be discussed.

“When we did Ultium we wanted to span the light commercial vehicles and heavy-duty vehicles all the way down to a small SUV, and our optimization just worked out there,” says Grewe.

“There are other OEMs that have a very similar structure with this, where they have a cell module assembly and a little less energy, and they generally don’t go as far as we go up in terms of size of vehicle and energy storage,” he continues. “Ultium is one architecture across all of that. The closest competitor has two architectures and manages that with two different submodules and assemblies. Many OEMs have three or four architectures. We think that this was an optimization around our portfolio and our needs.”

There’s a lot of commonality in some of the components and chemistry composition today, but Grewe says GM is running continuous design loops looking at alternatives that could take the energy from the existing 620Wh per liter to 850Wh, even 1,100Wh with lithium metal anodes. This could reduce the pack size and therefore the mass in a vehicle, all of which are scenarios being looked at as the technology evolves.

Recycle and reuse
GM is investing in raw material ventures while also looking to a future where it is less reliant on mining and more reliant on recycling.

Every OEM is conscious of the need to have a secure and sustainable flow of raw materials to meet electrification needs. This is also true for GM, which has supply agreements in place until 2025.

“Our goal for a secure value chain is to get 120% of our needs secured well ahead of our expansion,” says Grewe. Currently most of GM’s lithium supply comes from Australia but it is looking to localize to reduce costs while also seeking out better technology.

GM has invested in a company called Controlled Thermal Resources, which undertakes direct lithium extraction from lithium brine in the San Andreas Fault in California. GM is also collaborating on a cathode active material factory with Pasco Chemical Company in Canada, which uses low-cost hydro energy. Ultimately, Grewe hopes to reach a point where there is less reliance on new raw materials.

“We recycle every battery we get and we provide our customers with a recycling pass, although it’s only a recommendation as technically we don’t own those batteries,” he says.

Test runs
GM’s Estes Lab at its Global Technical Center in Michigan is responsible for development and testing of battery cells.

GM has joint ventures with LG Energy Solutions in Lordstown, Ohio, and Spring Hill, Tennessee, to manufacture battery cells, but its development and testing takes place in the Estes Lab at the Global Technical Center in Michigan.

APTI took a tour of the facility with Eric Boor, senior leader at GM. There, batteries, including the latest BEV3 Ultium, are run through test cycles for anything from one hour to three years. The test rigs can push up to 500A into each cell, which Boor says is the maximum current they are willing to use from a safety perspective.

The facility can test individual cells, cell module assemblies and full packs, and even multiple packs in the case of tests for the Hummer EV. Each cell can be subjected to a multitude of operating conditions at once, including power and temperature variations, with equipment to test between -68°C and +89°C and 5-95% relative humidity.

The star of the facility is a large, climate-controlled shaker rig, similar in size to those used by Boeing to test airframes.

“We can vibrate from zero to 2,000Hz, which will simulate any road condition our customers are going to go through,” says Boor. “The drum will rotate in three axes, so we can give x-axis, y-axis and z-axis shapes to simulate a battery in all the different corresponding environments that it is going to go through.”

The lab can also simulate a range of temperature and humidity conditions, but more than that, can push up to 1,500kW of energy into a battery pack at 1,500A, which is essential for testing the Hummer EV battery pack, in particular the so-called Watts to Freedom launch control feature, which can draw out 1MW in as little as three seconds.

A new technology kit has been revealed by Mahle which partners the company’s benchmark SCT (superior continuous torque) and MCT (magnet-free contactless transmitter) electric motors.

Mahle claims that its SCT electric motor is the only electric traction motor currently available that is able to deliver high power continuously, making the technology suitable for use in commercial vehicle applications. Furthermore, the company’s MCT electric motor is extremely efficient and uses no rare earth metals. The combination is stated to deliver a high peak power, contactless and wear-free power transmission and a high level of efficiency.

Alongside the electric motor technology, Mahle has also developed a new thermal management module which partners a range of thermal management componentry – including the heat exchanger, coolant pumps, condenser, chiller, sensors and valves. The resulting thermal management module is compact by design, enabling more design freedom for manufacturers.

By utilizing the thermal module, Mahle claims up to 20% more cruising range can be achieved in a system using a heat pump when compared to alternative pure electric heater architectures. Furthermore, enhanced cooling performance also improves fast-charging times.

Due to BEVs providing Mahle with a sales potential nearly three times higher than vehicles with ICEs, the company is continuing to focus on electric drives and intelligent charging technologies.

The products will be debuted to the public at IAA Mobility in Munich, Germany in September.

For more Mahle news, click here.