EME 023

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58 Deep insight: Immersion cooling Discussing the advantages of immersion cooling and the various forms that approach can take 66 Focus: Battery inspection Getting inside a battery to check its integrity or to trace a fault in a non-destructive manner is technologically challenging, as we explain 74 PS: A question of bandgap Wide bandgap semiconductors can be SiC or GaN: which would win in a fight? We explore that question 4 Intro Materials are a key to e-mobility designs, whether for lightweight structures or with the latest developments in battery coatings, or for exploitation of phase change materials 6 The Grid We consider how axial flux motors and in-fan motors are driving innovation on the ground and in the air, new LFP cells that charge in only six minutes and much more… 16 In conversation: Tony Persson Scania AB’s head of battery production explains his company’s key role in the development of electric vehicles for demanding applications 20 Dossier: H3X How the Colorado-based firm is boosting the power density of its motor drives to take electric aircraft even further 34 Focus: Phase change materials Phase change materials offer intriguing possibilities in the thermal management of EV powertrains 44 Insight: Battery coatings We find complex challenges within the development of coatings for battery applications 52 Digest: Pulse 63 electric RHIB We explore a new generation rigid hull inflatable boat that obtains benchmark performance from electrical energy 34 66 20 58 3 E-Mobility Engineering | January/February 2024 January/February 2024 | Contents

THE COMMUNICATIONS HUB OF THE ELECTRIFIED POWERTRAIN Read all back issues and exclusive online-only content at www.emobility-engineering.com ISSUE 023 | JAN/FEB 2024 UK £15 USA $30 EUROPE €22 The appliance of science Thermal chameleons Insight into battery coatings Phase change materials for heat control Simple, small, sustainable Electric aviation is no flight of fancy for H3X Into top gear on innovation Publisher Nick Ancell Editorial Director Ian Bamsey Technology Editor Nick Flaherty Production Editor Vickie Johnstone Contributors Peter Donaldson Rory Jackson Technical Consultants Ryan Maughan Danson Joseph Dr Nabeel Shirazee Design Andrew Metcalfe Ad Sales Please direct all enquiries to Nick Ancell nick@highpowermedia.com Tel: +44 1934 713957 Subscriptions Please direct all enquiries to Frankie Robins frankie@highpowermedia.com Tel: +44 1934 713957 Publishing Director Simon Moss Marketing & PR Manager Claire Ancell General Manager Chris Perry Office Administrator Lisa Selley Volume Six | Issue One January/February 2024 High Power Media Limited Whitfield House, Cheddar Road, Wedmore, Somerset, BS28 4EJ, England Tel: +44 1934 713957 www.highpowermedia.com ISSN 2631-4193 Printed in Great Britain ©High Power Media All rights reserved. Reproduction (in whole or in part) of any article or illustration without the written permission of the publisher is strictly prohibited. While care is taken to ensure the accuracy of information herein, the publisher can accept no liability for errors or omissions. Nor can responsibility be accepted for the content of any advertisement. SUBSCRIPTIONS Subscriptions are available from High Power Media at the address above or directly from our website www.highpowermedia.com. Overseas copies are sent via air mail. EDITORIAL OPPORTUNITIES Do you have a strong technical knowledge of one or more aspects of e-mobility systems? As we grow we are on the lookout for experts who can contribute to these pages. If that sounds an interesting challenge then don’t hesitate to explore the possibility of writing for us by emailing ian@highpowermedia.com ADVERTISING OPPORTUNITIES If you are looking to promote your company to engineers active in the electrification of vehicles, we have various advertising packages available to suit your needs. With a maximum of 25% of the publication allocated to advertising we offer a unique opportunity to become one of E-Mobility Engineering’s exclusive advertising partners, ensuring you are not lost in a crowded market. To discuss the opportunities and how we can work with you to promote your company please contact Nick Ancell nick@highpowermedia.com +44 1934 713957 THE COMMUNICATIONS HUB OF THE ELECTRIFIED POWERTRAIN SUBSCRIBE TODAY visit www.highpowermedia.com ALSO FROM HPM Materials are a key part of the development of e-mobility designs. Whether for lightweight structures or the latest developments in battery coatings (p44), the new generation of phase change materials (p34) or immersive cooling systems (p58) used for cooling the platform and boosting the thermal management. These are allowing for smaller battery packs with reliable and safe fast-charging in a matter of minutes in a fundamental shift in platform design. We talk with Tony Persson, head of battery production at Scania, about the latest technology insights on commercial vehicles (p16), as well as the inspection technologies (p66) that are needed to ensure reliability in e-mobility systems. In the meantime, axial flux motors and in-fan motors are driving innovation on the ground and in the air, as discussed in Grid (p6). When these are coupled with faster charging and smaller, lighter systems, the industry is shifting into top gear on innovation. Nick Flaherty l Technology Editor EME Update Each month the E-Mobility Engineering e-newsletter provides a snapshot of the top stories on our website during the previous month. To keep up to date with the latest technological developments, sign up today at www.emobility-engineering.com/e-newsletter 4 January/February 2024 | E-Mobility Engineering Intro | January/February 2024 Read all back issues online www.ust-media.com UST 53 : DEC/JAN 2024 UK £15, USA $30, EUROPE €22 High concept How the Zephyr solar-powered UAV aims to provide commercial services from the stratosphere Conscious uncoupling The advantages of separating real-time operating systems into kernels Heat waves The latest in multi-spectral thermal imaging systems ELECTRIC, HYBRID & INTERNAL COMBUSTION for PERFORMANCE ISSUE 150 DECEMBER/JANUARY 2024 Evade devastating shake! Focus on vibration analysis A V8 to conquer the Wild West The challenge of Dirt Late Model Racing to rescue the ICE AVL’s hydrogen-fuelled I4 turbo www.highpowermedia.com UK £15, US/CN $25, EUROPE e22

Charging forward to make zero-emission transportation work Customized cooling Our high-voltage eFan ensures e cient cooling in all-electric heavy-duty trucks.

6 The Grid Successful test of aircraft rim motor Duxion Motors has successfully ground tested its patented eJet Motor for electric aviation, writes Nick Flaherty. The successful ground testing of the scaled prototype at Summerside, Prince Edward Island, Canada, included both low-speed and high-speed testing. The patented rim driven design of the eJet motor uses permanent magnet technology and a new hybrid cooling system to deliver a higher power to weight ratio for the electrification of jet aircraft. The integrated ducted fan system adds forced convective cooling to the liquid cooling system, increasing power density and reliability. With today’s ducted fan propulsion systems, the motor is typically located inside the duct and coaxial with the fan and the fan blades attached to a central hub connected to a motor shaft. To achieve a higher thrust, a motor with a higher power rating may be used. However, motors with higher power ratings tend to have larger outer diameters, which reduce propulsion efficiency when the motor is located inside the duct. To compensate for efficiency losses due to the motor being located downstream of the fan blades, the fan blades are longer to generate the necessary level of thrust. However, a larger motor and larger fan blades significantly increase the weight of the propulsion system and as the size and weight of the propulsion system increases, the thrust-to-weight ratio for the system typically goes down. This type of system may also suffer from significantly increased vibrations which leads to more frequent maintenance, increased vulnerability to mechanical failure and/or generate higher levels of audible noise. Instead of this approach and its drawbacks, in the eJet the ducted fan blades are integrated into the motor for higher efficiency. This removes the need for a driven motor shaft and increases propulsion efficiency. Putting the motor in the rim allows a relatively high aspect ratio between the diameter and axial length to accommodate a set of polyphase multi-polar stator windings. This enables scaling to higher output power without reaching magnetic saturation in the yoke or in the teeth of the stator. One of the issues with such a design is the centrifugal forces and/or hoop stresses during high speed operation, so some components of the rotor and fan assembly are pre-loaded in a radial direction during their manufacture and/or assembly. This means these components are under compression when the rotor and fan assembly is at rest. For example, rotor magnets positioned on an outer surface of the shroud and/or the fan blades may be pre-loaded in compression. By preloading components of the rotor and fan assembly, a portion of the centrifugal forces generated during rotation of the rotor and fan assembly may be effectively offset by relieving the precompressed stress. This results in less net tensile stress on the rotor and fan assembly during high-speed operation. With the rim motor, the stator of the motor is positioned in the nacelle and comprises one or more stator windings while the rotor and fan assembly is positioned in the primary flow path. The rotor and fan assembly has multiple rotor magnets positioned on the outer surface of the fan shroud and concentric with the one or more stator windings. The fan hub is mounted on a central support shaft via one or more bearings and multiple fan blades extend between the inner surface of the fan shroud and the outer surface of the fan hub. ELECTRIC AVIATION January/February 2024 | E-Mobility Engineering The in-rim electric motor for aviation (Image courtesy of Duxion)

The Grid 7 In wheel motor development YASA is working with Domin on an in-wheel motor system that weighs under 2 kg, writes Nick Flaherty. The project with Cranfield University in the UK will create a patented in-wheel motor design using YASA’s axial flux motor and Domin’s digitally controlled hydraulic active suspension. The aim is to develop a motor system that is ten times lighter than the current 12 kg motor package design. The Mercedes Vision OneEleven Hypercar concept already uses YASA’s motor technology, which generates 250 bhp for it. Cranfield University will provide digital twin modelling and vehicle powertrain design optimisation alongside simulation of the design. The digital twin is a detailed digital model of the motor and suspension that allows engineers to tweak different parameters to see how the performance can be improved by boosting the power of the motor or reducing the weight. Putting the motor in the wheel reduces the need for a driveshaft, reducing the overall weight, but this changes the suspension requirements for the wheel. Domin uses electrically controlled distributed movement with electrified hydraulic power generation systems for a compact electrical motor and pump unit. Servovalves are sophisticated devices used for precise control of fluid flow and pressure in hydraulic systems and are typically made using traditional manufacturing methods such as machining, casting, or forging. Using additive manufacturing, or 3D printing, for the valves and other parts of the hydraulic system provides advantages such as design freedom, less parts and more efficient manufacturing processes for a lighter suspension system. The additive manufacturing enables the creation of intricate internal passages, channels, and fluid flow paths that are challenging or impossible to achieve using traditional manufacturing techniques. This enhances the performance and efficiency of servovalves by optimising fluid dynamics and reducing pressure losses. Digital control using a proportional– integral–derivative (PID) algorithm allows for precise and variable control of the fluid flow and pressure in servovalves while digital signal processing algorithms developed by Domin enable real-time monitoring, filtering, and adjustment of control signals, improving the overall performance and stability of the servovalves. The valves also use a brushless DC (BLDC) electric motor. Rather than using brushes and commutators, brushless DC motors use electronic controllers and permanent magnets to create rotational motion. This type is generally not used in hydraulics components, with manufacturers preferring to use cheaper options like solenoids or limited angle torque motors. Domin uses brushless DC motors for high-precision applications such as the inwheel motor as it provides uninterrupted rotational movement with tight control over both speed and position, unlike solenoids, which become less efficient with prolonged use. Brushless DC motors also have a longer lifespan by eliminating brush-wear and minimising maintenance requirements. These BLDC motors also use magnetic position sensors to measure the position or movement of the rotor using magnetic fields. The non-contact position sensors eliminate mechanical wear and tear, minimising maintenance requirements and extending the sensor’s lifespan. This approach also reduces the risk of sensor malfunction due to debris, contaminants, or vibrations present in the hydraulic system. The digital control allows the use of a CAN (Controller Area Network) interface for integration with other electronic systems, controllers, and supervisory systems, reducing the need for an additional electronic control unit. The digital controller monitors various parameters, such as temperature, current draw, motor faults, and voltage, to detect faults or anomalies. Advanced diagnostic algorithms and built-in self-diagnostic features enable real-time fault detection and this has the potential to deliver notification and preventive maintenance. This analysis data can be included in the digital twin to provide more visibility of the performance of the motor and to highlight if a part of the system is failing. EV PROPULSION E-Mobility Engineering | January/February 2024 The YASA Axial motor (Image courtesy of Mercedes)

The Grid Lead-less transistor packaging ChatGPT for battery chemicals Alpha and Omega Semiconductor (AOS) has developed lead-less packaging for its automotive grade 80V and 100V MOSFET transistors for two and three wheelers, writes Nick Flaherty. The lead-less packaging is a key step in making battery packs and brushless DC motors smaller in two and three wheel scooters. Removing the leads inside and outside the package helps to lower the resistance to 1.25 mOhms and 1.7 mOhms, giving lower losses and allowing higher efficiency for light vehicles. To achieve the lead-less packaging, AOS developed a clip for the transistors that supports a high in-rush current rating of 1780 A for the 80 V parts and 1480 A for the 100 V parts. The 80 V also has a continuous current of 247 A at a usable temperature of 100 C and is rated to 445 A at 25 C, while the 100 V parts support a current of 269 V at 100 C (and 370 V at 25 C). This also means the parts have a 30% smaller footprint than the TO-263 (D2PAK) packages that are lead-less outside but still use bond wires to connect the die to the lead frame of the package. A team of researchers led by the University of Michigan in the US is developing a generative AI model to produce new molecules for batteries, writes Nick Flaherty. The machine learning framework will be developed using 200,000 node hours on the Polaris, a 34-petaflop supercomputer at Argonne National Laboratory. The team will build a foundational model for molecules, similar to the GPT models that support applications such as ChatGPT. The new model will focus on small organic molecules with relevance to batteries. The chemical model will be fed text-based representations of atomic structures with no additional information like chemical properties. It will be used to predict better battery electrolytes. When the model is able to predict missing atoms in small organic compounds, the team will move on to fine-tuning—feeding it the properties of some compounds and asking it to predict the properties of others. Through iterative feedback, they intend to build an AI that can master small organic molecule chemistry. Once the model is up and running, the team will ask it to predict electrolytes suited to a particular pair of electrodes. It will then experimentally test each prescription in the lab with a robotic setup, Clio. The lower resistance and inductance of the AOS TOLL packaging clip technology also improves the electromagnetic interference. This combination of low ohmic and high current capability allows designers to reduce the number of parallel MOSFETs in high current applications. This, in turn, helps to enable higher power density requirements without compromising reliability in applications where robustness and reliability are key design objectives. “Using the AOS Automotive TOLL package with clip technology offers significant performance improvements in a robust package” said Peter Wilson, Marketing Sr. Director of MOSFET product line at AOS. “The advanced technologies in our AOTL66810Q and AOTL66912Q MOSFETs will help simplify new designs, allowing them to reduce the number of devices in parallel while providing the necessary higher current capability to enable overall system cost savings.” ELECTRIC SCOOTERS BATTERY TECH 8 January/February 2024 | E-Mobility Engineering TOLL packages for two wheelers (Image courtesy of Alpha and Omega Semiconductor)

Japanese precision since 1935 Test solutions for R&D, Production and Quality Assurance Benefit from 35 years of experience in electronic measurement technology for lithium-ion batteries. hioki@hioki.eu www.hioki.eu Battery Testing from Cell to Pack

10 BATTERY TECH January/February 2024 | E-Mobility Engineering LFP cells charge in six minutes DESTEN has developed the first Lithium Iron Phosphate (LFP) cell that can charge in just six minutes at 6 C writes Nick Flaherty. The 160 Wh/kg pouch cell developed by DESTEN is capable of charging from 20% to 80% SOC in six minutes at a charging rate of 6 C. Moreover, the LFP chemistry means the cell is intrinsically safer than lithium ion cells. There are numerous battery characteristics which must be taken into account when evaluating the applicability of a particular cell technology. DESTEN’s cells not only provide strong charge and discharge profiles, but also high energy density, long life cycles and stability. They are claimed to have industry competitive pricing. To have each aspect in abundance is critical; underperformance across any of these characteristics limits the applicability of the cell to meet the needs of users. In the case of EVs, be it driving safely or having enough capacity integrated into a car to achieve a desired range, a good battery technology is able to contribute to a well rounded and ICE comparable driving experience. As well as 6C fast charging, these cells can discharge at the same rate. This allows a higher power output from a battery pack for offroad and construction vehicles. This fast charge and discharge ability comes from ensuring compatibility across each cell component. DESTEN develops its own specialised anodes, cathodes, electrolyte and separator to all work together. It has also developed and formulated specialised nanomaterial additives and dopants to promote the capabilities of the materials used across the cell components. All of this means that the temperature of the cell rises by less than 15 C during the 6 C charging and discharging. The LFP cells support up to 3000 charging cycles before the state of health (SoH) of the cell falls to 80%, and using LFP means the cells operate in temperatures from -20 to +45 C, which is a difficult achievement for lithium ion cells. However lithium ion cells with silicon anodes have an energy density over 400 Wh/kg, which means more of the LFP cells are required to provide the same energy, potentially making battery packs larger and heavier. However as the packs can be charged in just six minutes they can be smaller if there is a high power charger available as they can be recharged more frequently. “Our latest technological breakthrough has the potential to revolutionise transportation and energy storage applications”, remarked Bader Al-Rezaihan, CEO and Chairman of DESTEN. “Making ultra-fast charging cost competitive with iron phosphate material formats will resolve key adoption barriers for EV drivers.” DESTEN is now working with its partners in North America, Europe and Asia to integrate the cells into electric vehicle platforms, delivering the first samples to platform makers. An LFP cell that charges in 2 minutes (Image courtesy of DESTEN)

The Grid 11 BATTERY TECH E-Mobility Engineering | January/February 2024 The smart switch (Image courtesy of Kyocera AVX) Smart switch protects 800V battery packs Kyocera AVX has developed a smart semiconductor switch for EV battery pack designs, writes Nick Flaherty. The switch supports voltage levels up to 930 V for 800 V battery packs and is able to withstand short current events up to several thousand amps. Using a scalable design, the switch can be adapted to different power classes up to 640 kW continuous performance and provides both a safety cutoff and also support for higher charging rates. The high requirements and increased integration of additional safety-relevant features in the vehicle electrical system architecture mean a semiconductorbased design can provide marked advantages when compared to a mechanical relay, including considerably higher switching speeds. Particularly in the event of a short circuit, every microsecond counts in order to guarantee a safe disconnect. The Kyocera AVX Electrical Smart Switch protects the supply circuit during charging and discharging bi-directionally in the event of overcharging or in the event of a short circuit. In addition, the Electrical Smart Switch permits the precharging of the DC network to enhance the service life of system components. In the event of a short circuit, the electrical smart switch turns off in a few microseconds and thereby may prevent severe damage to the supply circuit. Inrush current peaks can be prevented by using the implemented pre-charge function. Using this function the current is limited by pulsing with a frequency up to 100 kHz and thereby is another important gain made whereby overall system costs can be lowered. Thermal efficiency The thermal efficiency of the switch is boosted through a combination of high-level assembly technology and temperature sensing, which monitors the device temperature and provides real time feedback. The electrical smart switch was developed using the specialist ceramic substrate skills at Kyocera AVX in Salzberg, Austria. “There is no such product as the electronic switch on the market replacing the relay in the battery,” said Gerhard Kock, R&D manager at the site. The module is based around an array of 24 1200 V silicon carbide (SiC) MOSFET transistors so that it can control the current flow both in and out of the battery pack, with 12 MOSFETs directing the current in each direction. The array is controlled by a single gate driver and provides a short circuit current protection of 2300 V in under one microsecond. The energy in the system is managed by TVS diodes to handle the short circuit current as there is still energy in the system from the inductance that in a mechanical relay can cause the contacts to fuse. The TVS diodes are mounted in parallel with the MOSFETs so the MOSFETs don’t enter avalanche mode, and it is the speed of these TVS diodes that limits the response of the switch to under 1 microsecond, or 100 kHz, rather than a nanosecond response. The switch has also been tested with 1.5m cycles for endurance for automotive applications. Thermal performance is a major challenge in such a module so the engineers used a silicon nitride ceramic substrate directly soldered to a baseplate with cooling from pin fins to the baseplate. Several NTC temperature sensors are mounted on the substrate to directly monitor the substrate to reduce the current flowing through the switch as an additional safety function. DC-link Using the switch can also eliminate the pre-charge circuit on the DC-link inverter and using a pulsing function can increase the charging rate from C1 to C2 and can be combined with a supercapacitor. The next stage is to integrate a current sensor into the module so it can be autonomous, rather than using a current sensor external to the rest of the battery pack.

Technical consultants Ryan Maughan is an award-winning engineer and business leader with more than 20 years’ experience in the High-Performance, Heavy-Duty and Off-Highway Automotive markets. Prominent in the development of Power Electronics, Electric Motors and Drives (PEMD) for these demanding applications, he has successfully founded, scaled and exited three businesses in the electric vehicle space. He is currently CEO of eTech49 Limited, an advisory business specialising in disruptive hardware technology in PEMD. In addition, he is Chairman of EV North, an industry group representing the booming EV industry in the north of England, a board member of the North East LEP and an adviser to a number of corporations. Danson Joseph has had a varied career in the electrical power industry, having worked in areas ranging from systems engineering of photovoltaic powerplants to developing the battery packs for Jaguar Land Rover’s I-Pace SUV. With a PhD in electrical machines from the University of Witwatersrand in South Africa, Danson has focused on developing battery systems for automotive use. After completing the I-Pace project he formed Danecca, a battery development company with a focus on prototyping and small-scale production work, as well as testing and verifying cells and packs destined for mass production. Dr Nabeel Shirazee graduated from Leicester University in 1990, where he studied electrical and electronic engineering. An MSc in magnetic engineering followed at Cardiff University, where he continued his studies, earning a PhD and developing a permanent magnetic lifting system that has been patented by the university. His interest in magnetics led to a patented magnetic levitation system that was awarded the World’s No 1 Invention prize at INPEX in the USA. In 1999, he founded Electronica, a magnetics research and design consultancy. Since then, he has been involved in various projects, including the design of an actuator motor for a British aerospace company. He has also licensed the levitation technology in France. Ryan Maughan Danson Joseph Dr Nabeell Shiirazee Researchers in the US have developed a solid-state lithium-air battery cell with a potential energy density of 1000 Wh/kg (writes Nick Flaherty). The capacity is potentially four times that of the current lithium-ion battery technology used in heavy-duty vehicles such as aircraft, trains and submarines. The electrolyte is a mix of polymer and ceramic materials that takes advantage of the ceramics’ high ionic conductivity and the high stability and high interfacial connection of the polymer. The electrolyte is based on Li10GeP2S12 nanoparticles embedded in a polyethylene oxide polymer matrix. The result allows for the critical reversible reaction that enables the battery to function – lithium dioxide formation and decomposition – to occur at high rates at room temperature. It is the first demonstration of this in a lithium-air battery. “We found that solid-state electrolyte contributes around 75% of the total energy density,” said Mohammad Asadi, Assistant Professor of chemical engineering at Illinois Institute of Technology. “That tells us there is a lot of room for improvement, because we believe we can minimise that thickness without compromising performance, which would allow us to achieve a very high energy density.” Prof Asadi said he plans to work with industry partners to optimise the battery’s design and engineer it for manufacturing. The prototype cell is rechargeable for 1000 cycles with a low polarisation gap, and it can operate at high rates. BATTERIES Lithium-air’s quadruple potential The Grid March/April 2023 | E-Mobility Engineering 11 12 January/February 2024 | E-Mobility Engineering The Grid BATTERY TECH Combining machine learning and electrochemical models Eatron Technologies and About:Energy are developing a decision-engine for battery management systems (BMS) that combines machine learning and electrochemical models, writes Nick Flaherty. The aiMAGINE project aims to use machine learning frameworks in the BMS to extend the life of a battery pack in electric vehicles and scooters. Current BMS rely on simple, empirical methods that sacrifice accuracy in return for reduced computational effort. However conventional AI methods remain challenging to integrate within the BMS due to their complexity, demanding training process, and the need for large volumes of input data. The aiMAGINE project combines About:Energy’s electrochemical battery models that achieve rapid and accurate calibration with Eatron’s edge and AIpowered cloud platform. This should provide more accurate assessments of state-of-charge (SoC), state-of-health (SoH) and (patented) remaining useful life predictions. The AI complements the electrochemical models, enhancing predictions by accounting for complex physical behaviours that cannot be modelled. This will allow the AI-powered decision engine (AI-DE) to provide highly accurate operational parameters to the BMS, significantly increasing battery pack longevity and simplifying integration. “Implementing our novel AI-powered intelligent battery software layer with this revolutionary AI-DE can extend a battery pack’s first life by up to 20%,” said Dr Umut Genc, CEO of Eatron.

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E-Mobility Awards Thursday 25 January British Motor Museum, Warwickshire www.e-mobilityawards.com CAEV Expo 2024 Thursday 14 – Friday 15 March Bengaluru, India www.caevexpo.in The 2nd European Automotive Decarbonization and Sustainability Summit 2024 Tuesday 19 – Wednesday 20 March Frankfurt, Germany www.ecvinternational.com/EuropeanAutomotive Vehicle & Transportation Technology Innovation Meetings Tuesday 26 – Wednesday 27 March Torino, Italy italy.vehiclemeetings.com EVS 37 The 37th International Electric Vehicle Symposium & Exhibition Tuesday 23 – Friday 26 April Seoul, South Korea www.evs37korea.org Vehicle Electrification Expo Wednesday 15 – Thursday 16 May Birmingham, UK www.ve-expo.com Battery Cells & Systems Expo Wednesday 15 – Thursday 16 May Birmingham, UK www.batterysystemsexpo.com Future Mobility Asia 2024 Wednesday 15 – Friday 17 May Bangkok, Thailand www.future-mobility.asia The Magnetics Show Wednesday 22 – Thursday 23 May California, USA www.magnetics-show.com busworld Wednesday 29 – Friday 31 May Istanbul, Turkey www.busworldturkey.org The Battery Show Europe Tuesday 18 – Thursday 20 June Stuttgart, Germany www.thebatteryshow.eu 2024 IEEE Transportation Electrification Conference & Expo Wednesday 19 – Friday 21 June Rosemont, USA www.itec-conf.com MOVE 2024 Wednesday 19 – Thursday 20 June London, UK www.terrapinn.com Foam Expo North America Tuesday 25 – Thursday 27 June Novi, Michigan www.foam-expo.com Adhesives & Bonding Expo Tuesday 25 – Thursday 27 June Novi, Michigan www.adhesivesandbondingexpo.com World Battery & Energy Storage Industry Expo Thursday 8 – Saturday 10 August Guangzhou, China en.battery-expo.com IAA Transportation 2024 Tuesday 17 – Sunday 22 September Hannover, Germany www.iaa-transportation.com The Battery Show USA Monday 7 – Thursday 10 October Michigan, USA www.thebatteryshow.com Electric & Hybrid Vehicle Technology Expo Monday 7 – Thursday 10 October Michigan, USA www.evtechexpo.com 14 Diary January/February 2024 | E-Mobility Engineering

16 January/February 2024 | E-Mobility Engineering Scania AB’s head of battery production Tony Persson explains to Rory Jackson his company’s key role in the development of electric vehicles for demanding applications Pushing the limits The race to electrify road vehicles is bringing with it a race to develop internal competencies in producing key e-mobility technologies, and battery packs frequently make the top of the list. As of mid-2023, around 30 battery factories were planned, being built, or already operational in the US, with around 35 in the EU and several times more in China. Major OEMs of large commercial vehicles are particularly driven to hone their capabilities in battery engineering and manufacturing as heavy trucks, lorries and buses have unique physical and performance needs. This affects how optimal batteries for such applications must be designed and produced. As Scania AB’s head of battery production, Tony Persson is closely acquainted with those needs, and with the steps that the Swedish multinational is taking to meet them in its current and coming generations of heavy electric vehicles. Though Persson had worked in Scania since 2000, starting then as an engineer and project manager, his first experiences with electrification took place between 10-15 years ago, by which time he had become manager for the production of all of Scania’s bus chassis. “We’d only ever produced ICE-powered buses by that time, but someone from Scania R&D came down to the production line and told us that they wanted to produce an electric Scania bus – this was still before Tesla had become a big name with either the Model 3 or its large-scale battery production, so it seemed a bizarre proposition at the time,” Persson recounts. “But I’m glad we took on that project. Even if it didn’t materialise into a massproduced electric bus at the time, it was a huge eye-opener for me that heavy commercial vehicles didn’t need to have a conventional drivetrain – that EVs were something that could work safely and efficiently – and that thought has stayed with me since then.” Though he took a sojourn away from employment in Scania and a foray into independent consulting starting in 2014 (including some indirect work for Scania), that lingering interest in what could have been an electric bus powertrain drove him to return to the Swedish multinational in 2019. That was As Scania’s head of battery production, Tony Persson is managing the Swedish OEM’s growing capabilities in heavy vehicle electrification (Images by Dan Boman, courtesy of Scania)

E-Mobility Engineering | January/February 2024 17 Tony Persson | In conversation and which should be outsourced.” For instance, given the particular skill sets, knowledge and large-scale processes needed to create battery cells, Scania has opted not to research or produce these in-house. Instead it utilises cells from Northvolt, whose head office, laboratories and design facility are conveniently near to Scania’s battery factory in Södertälje. “By comparison, the processes and skills needed for assembly of battery modules and packs are the same or closely linked in many ways to those already utilised in Scania’s manufacturing centres,” Persson says. “Our design department meanwhile focuses most of their work on optimising and simulating the designs of our modules and packs, but also does some work in designing cells for our use in partnership with Northvolt’s design department.” For heavy EVs such as those being designed by Scania, Northvolt manufactures and supplies a cell designed with an NMC cathode and in a prismatic format. This is identical to that used in the Audi-Porsche Premium Platform Electric (PPE) modular skateboard powertrain (that system being detailed further in our cover story on p.20). “The chemistry has been specifically tailored for the endurance and lifetime requirements of heavy vehicles – trucks and buses, specifically – such as meeting a lifetime expectancy of 1.5 million kilometres’ worth of operations, which we regard as an outstanding parameter for Northvolt to have achieved,” Persson comments. As extra motivation for leveraging Northvolt cells in Scania’s future commercial EVs, Persson makes reference to reports that the Northvolt cell is to be the “greenest” on the market, owing to that company’s use of recycled materials in manufacturing its batteries, as well as its use of clean grid energy to power its production lines. This is thanks to partners and investors such as Vattenfall (which, as discussed in issue 18, Mar/Apr 2023, aims to supply renewable energy to e-mobility and other industries seeking to output products with zero emissions from production through to end-of-life). A couple of examples of Scania’s new generation of heavy electric vehicles have already been announced. For instance in 2019, Scania announced a battery-electric version of its Citywide city bus, which entered production in 2022. Sized for a seating capacity of 35 passengers and a total capacity of 100 persons, the Citywide BEV can integrate either 8 or 10 packs, for up to 254 kWh or 330 kWh of NMC-based energy storage. Both selections entail an estimated 320 km of range depending on driving, operational and environmental conditions (the 10 pack option likely being recommended for more energyintensive routes and locations). The Citywide BEV’s powertrain integrates an oil spray cooled electric motor built for 250 kW of continuous power and 300 kW of peak output, as well as a two-speed gearbox and a braking system combining energy recuperation with electro-pneumatic disc brakes. Additionally in 2020, the company announced the official market launch of its first battery-electric truck model when the opportunity arose to rejoin as head of battery production at the company’s new battery assembly plant at Södertälje in Stockholm County. “Since before my university days doing a Masters in Engineering at Lulea in northern Sweden, I’ve always been interested in new areas of technology, particularly when it requires working on new skills and new perspectives; so I applied for the job and I’ve been working to develop Scania’s outsourced production of energy storage systems for electrified trucks and buses ever since.” Heavy commercial EVs As many readers will already be aware, heavy commercial EVs require a number of different parameters in their battery packs compared to those in passenger cars. “For instance, the big one for us is that heavy trucks may be required to operate over 24/7 periods, rather than the regular lengthy rest or slow recharging periods that passenger cars get, between some commuting here and there for much shorter periods than those trucks or even buses work,” Persson notes. “That has an impact on the kinds of cells and other components you choose, which in turn impacts what aspects of battery production should be performed in-house EU laws state that truck drivers can drive 4.5 hours, then must take a 45 minute break; this sets Scania’s engineering targets for its truck battery packs’ endurance and charging times

18 (simply called Scania BEV) which comes with either a five module battery pack for a capacity of 165 kWh and a range of 130 km, or a nine module pack storing up to 300 kWh and enabling 250 km of driving distance. The Scania BEV integrates one of its battery modules in what used to be the engine tunnel, with the chassis mounting the remaining four to eight modules, and its electric motor produces up to 230 kW. “These were vehicles aimed at urban transportations of people and goods, and hence the kinds of distances needed for driving within city limits, but in 2023 we started production of our first regional truck platform for long-haul freight movement, and in Brussels in October we announced our first regional electric bus too,” Persson notes. Key enhancements for the regional trucks over the urban truck (which comes in both trailer and rigid versions, and up to 64 tonnes gross train weight) include bigger battery packs with up to 624 kWh of energy and so enabling up to 390 km of range between charges depending on driving style, weather, payload and other factors. “Regulations define our pack engineering and integration philosophy somewhat there: legislation dictates that truck drivers are allowed to drive for four-and-a-half hours, and then they must take a 45 minute break before they can drive four-and-a-half hours again,” Persson says. “That strongly influences boundaries for how much energy you want or need to store on the trucks, as do EU rules saying that you can carry up to 40 t of weight on trucks, or 42 t for EV trucks as it’s estimated that electric truck powertrains are about 2 t heavier than their ICE-based counterparts. So we’ve designed the packs to enable 4.5 hours of driving and then to accept fast-charging to replenish them in 45 minutes.” They will also feature larger e-motors, which come as part of Scania’s new EM C1-4 powertrain series. These are designed as single permanent magnet synchronous machines combined in a single unit with a four-speed gearbox. Scania has announced the powertrain will be supplied in five different power levels (270, 300, 330, 360, 400 and 450 kW), enabling the regional e-trucks to match the hauling power needed for varying routes and applications. Similarly, Scania’s regional electric bus will integrate much larger packs than its urban counterpart. One option is to carry four such packs for 416 kWh, with the other being five packs for 520 kWh. Range estimates for either configuration are currently at least 400 km for the lower pack count and at least 500 km for the greater figure; these also come with fast-charging times of approximately 150 minutes and 170 minutes respectively, their packs having been engineered for 200 A DC plug-in rechargers as of writing. Its motor meanwhile will be an e-machine designed for 300 kW peak output and 250 kW of continuous power. Industry 4.0 Future work towards key enabling technologies for commercial e-mobility such as faster-charging batteries, more energy- and power-efficient drivetrains, and more resource-efficient production is aided by the proximity of Scania’s battery factory to numerous electrification-centric universities. Persson highlights for instance KTH (the Royal Institute of Technology) in Stockholm: that university’s Integrated Transport Research Lab typically has numerous rolling research projects directly testing how differing configurations of electric vehicles, charging infrastructure, and EV route analytics can result in higher usage of sustainable mobility, lower nationwide emissions and better health of the Swedish population. “And there are several more; Uppsala University for example also has extensive research programmes within this field, collaborating directly with Northvolt via a Master’s Programme in Battery Technology and Energy Storage. Northvolt helped design that, though we also have connections there,” Persson says. “And farther afield from just straight e-mobility, there’s a business school in Stockholm which does excellent research in digitalisation. The factory that we’ve built here in Södertälje has all the necessary infrastructure laid for Industry 4.0, which via digitalisation will give us better control over production quality, efficiency, and so on, hence collaborations there are really helpful.” The factory’s module assembly line is fully automated as a baseline for future industrial technologies, with its present throughput consuming January/February 2024 | E-Mobility Engineering In conversation | Tony Persson EU laws state that truck drivers can drive 4.5 hours, then must take a 45 minute break; this sets Scania’s engineering targets for its truck battery packs’ endurance and charging times

19 one cell per second. Each of the commercial vehicle-bound cells weighs approximately 2.2 kg, and Persson comments that the ergonomics of handling such large cells requires an automated setup. “We’ve made sure to install a copious plethora of sensors to ensure we’re always measuring the state of our assembly equipment, of the processes, and of the products, all along the production line,” he says. “And one of the first steps in our facility involves testing all of the battery cells for parameters like performance over temperature, voltage and internal resistance, and we then compare our results in a database with results provided by Northvolt from their own testing processes. “But really, for me the biggest advantage of having sensors and measurement all over every part of the facility is being able to visualise any step in the production process at any given moment. We routinely set up visualisation layers to suit each operator at every machine on the shop floor, to aid them in monitoring the speed, consistency or health of each process, so they can instantly know how efficiently or safely each tool is operating in real-time.” On a larger scale, workshop or factory managers use all this data to visualise how well the facility is running, gauging values such as quality yields and machine uptimes, and pinpointing potential bottlenecks where some efficiency might be gained via reworks of or countermeasures within the production line. Persson additionally notes, “The assembly machines collect data on things like the torque curves of their implements. If machine learning-based AI can autonomously identify where one such curve is starting to shift, then it can trigger either a notification to maintenance teams for inspection or replacement, or even just a software correction by the machine to return its torque curve to normal. AI offers huge potential for maintenance teams to identify or predict risks of future degradation or equipment. “And I think we’ll be discovering more and better forms of welding in the near future; welding plays a huge part in the production of batteries, but each type of welding process comes with so many risks, so many things that need constant checking and control to prevent issues like forming errors or contaminations. If we speak again within two years, I wouldn’t be surprised to tell you that we’ve switched from laser welding to wire bonding or something like that.” Scania in operation The standard pack coming off this assembly line is presently a 700 V nominal unit storing 100 kWh of energy, though a bigger pack is also manufactured which modularly combines 200 kWh worth of modules, and also integrates two control units for added safety and redundancy. “The bigger packs are a critical enabler for the longer-distance transport EVs, and fortuitously we expect those systems to be very well ranged for moving people or materials between Northvolt’s facility and ours, as well as for the busy routes between Stockholm and its surrounding towns, or between the west and east coasts of Sweden with a single charging stop somewhere in the middle,” Persson notes. “I’ve also conversed about those packs with peers in Germany, and there’s for instance a route in Southern Bavaria, where one of the sports car manufacturers runs trucks for transporting huge pallets of cars from the factory to dealerships. It’s around a three hour loop for that truck to leave and return to the production centre, which is a perfect fit for the sort of 600 kWh EV we’re developing now; and as our facility produces batteries entirely using wind and hydro power, the only step that remains is instructing national and local governments on the need for better vehicle charging and electrical infrastructure to bring about zero-pollution mobility.” The future Persson says, “we’ve found our initial standard battery pack is a good fit for the mining industry, and for heavy construction vehicles. Leveraging new technologies will also be important and battery technologies will certainly evolve to enable trucks and buses to fast-charge in 30 minutes or less while maintaining long life expectancy. The next few years are going to be exciting.” E-Mobility Engineering | January/February 2024 Tony Persson Tony Persson studied a Masters in Engineering at Lulea University of Technology in the north of Sweden from 1994 to 2000. That education included a one year stint as a blue-collar worker at a Saab Automobile press shop from 1996 to 1997. He additionally achieved an MSc Eng in Manufacturing and Process Engineering from the University of South Australia in a placement that ran from 1999 to 2000. Following his graduation, he entered Scania and spent 14 years and 7 months working across a variety of positions, including engineer, project manager, and production manager, across different aspects of the Swedish company’s technical activities including chassis production, material handling and supplier quality assurance. He and his family moved to Kuala Lumpur, Malaysia for three years, then lived in Germany for around three further years before returning to Sweden to rejoin Scania as head of battery production. Outside of his career in e-mobility, Persson is also an Ironman-certified fitness coach, and to date still consults on matters of personal fitness and triathlon training, as well as management and business development.

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