THE COMMUNICATIONS HUB OF THE ELECTRIFIED POWERTRAIN Read all back issues and exclusive online-only content at www.emobility-engineering.com ISSUE 033 | SEPT/OCT 2025 UK £15 USA $30 EUROPE €22 Power boost Ultrafast-charging stations Playing it cool Managing battery thermal loads The future of waste collection is electric Mack’s sustainability
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4 Intro Sustainability is at the heart of current e-mobility design, not just in terms of ever more efficient performance but also with regard to the environmental impacts of the actual EVs themselves 6 The Grid Modular powertrains come under the spotlight, EV warning sounds are put to the test, resin-insulated SiC modules are shown to boost power density, in-wheel motors boost power and Nissan 5-in-1 e-power powertrain boosts efficiency 16 In conversation: Marlen Valverde The global technical manger ePower and energy storage at H.B. Fuller contemplates developments in adhesives, sealants and coatings used in EV batteries 20 Dossier: Mack LRe refuse truck A major player in the refuse vehicle market reveals details of how it’s set to clean up with a move to electrification 32 Focus: Battery pack materials Requirements for weight saving and greater safety regarding the battery packs of EVs are driving designers to consider using a range of existing and new materials 42 Show report: The Battery Show Europe 2025 The pick of a plethora of the latest battery-related innovations presented at The Battery Show Europe 2025, held in Stuttgart 56 20 50 50 Insight: Mining electrification The mining industry has set itself the goal of net zero carbon emissions by 2050, and electrification across the board could be the way to achieve it 56 Deep insight: Fastcharging technology Rapid tech developments mean that the days of EV charging in a time getting close to that required to refuel a traditional car are fast approaching 64 Focus: Battery cooling As demands for battery packs to deliver ever greater power increase, remaining cool has never been more important 74 PS: Open-source e-mobility The open-source movement could be a ‘spanner in the works’ or totally transform EV design and construction 3 E-Mobility Engineering | September/October 2025 September/October 2025 | Contents
THE COMMUNICATIONS HUB OF THE ELECTRIFIED POWERTRAIN Read all back issues and exclusive online-only content at www.emobility-engineering.com ISSUE 033 | SEPT/OCT 2025 UK £15 USA $30 EUROPE €22 Power boost Ultrafast-charging stations Playing it cool Managing battery thermal loads The future of waste collection is electric Mack’s sustainability Sustainable e-mobility Publisher Nick Ancell Technology Editor Nick Flaherty Contributors Peter Donaldson Will Gray Technical Consultants Ryan Maughan Danson Joseph Dr Nabeel Shirazee Design Andrew Metcalfe Sub Editor James Buxton 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 Operations Director Chris Perry Marketing & PR Manager Claire Ancell Office Administrator Lisa Selley Volume Seven | Issue Five September/October 2025 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 editorial@emobility-engineering.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 E-mobility engineers are at the forefront of sustainability in many different ways. The latest EV platforms designed for use on the ground and in the air must deliver high levels of performance. This is a challenge for sustainability, requiring new materials and techniques not just in terms of the actual vehicles but also in relation to the charging infrastructure. The Mack electric refuse truck, for example, highlights the move to electric operation for the more basic social infrastructure as we detail on page 20. Fast charging shortens the time taken to top up a battery pack and requires more sophisticated battery cooling strategies (page 64). But implementation of fast charging must also fit into the existing electricity grid. The strategies adopted for charging systems and how they fit into the grid without overwhelming it are detailed on page 56. End-of-life regulations in Europe are also focusing attention on the sustainability of battery enclosure materials (page 32), driving reductions in the carbon footprint and requirements for recycling as much of the vehicle as possible. The focus on materials is also at the heart of our interview with Marlen Valverde at adhesive supplier H.B. Fuller on page 16. All these elements are coming together to drive the sustainability of e-mobility designs while still advancing performance. Nick Flaherty Technology Editor 4 Intro | September/October 2025 September/October 2025 | E-Mobility Engineering Evolution in action How Tekever adapts its UAVs for a combat zone Health check Monitoring uncrewed system performance Cutting edge High-tech material machining Read all back issues online at www.uncrewed-systems.com Issue 63 : AUG/SEPT 2025 UK £15, USA $30, EUROPE €22 ELECTRIC, HYBRID & INTERNAL COMBUSTION for PERFORMANCE ISSUE 160 AUGUST/SEPTEMBER 2025 How clean is clean? Examining engine component hygiene 21st century hot rodders Drag-and- drive engines Pitchperfect Noonan’s high-performance V10 www.highpowermedia.com UK £15, US/CN $25, EUROPE €22
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6 The Grid Modular powertrain ZF has developed a modular drive system for EVs that boosts efficiency and reduces size, writes Nick Flaherty. The SELECT platform covers electric motors and transmission to the inverter and AI-enhanced control software. “If you just optimise one piece you miss out on the global optimisation and you have lower efficiency,” says Dr Otmar Scharrer, senior vice president r&d, electrified powertrain technology at ZF. “SELECT is the result of that optimisation. It’s a platform with four parts. The reducer is the transmission, which you definitely need in an EV as the motor runs faster than the wheels, and that needs a ratio of between 1:10 and 1:12. Then, we have the electric machine, the motor and the inverter and the software that is the brains of the system.” em:SELECT for electric motors, which covers both proven Permanently Excited Synchronous Machines and Asynchronous Machines through to new concept Separately Excited Synchronous Machines, does not need magnets that use rare earth elements (REEs). This avoids supply chain issues with REEs from China. This has 93% efficiency with peak power from 150 to 300 kW and torque from 3500 to 5500 Nm. The volume of 66 L is a reduction of 19%, while the weight of 89 kg is a 15% reduction compared with the latest systems. The 300 kW in:SELECT inverter supports both 800 and 400 V systems. “The idea of the in:SELECT was to develop a very scalable and modular platform, with variations that are suitable for the e-motor packaging, but that is just one variant,” says Matthias Zechmann product manager for the inverter platform. “The platform has both SiC and IGBT – where efficiency is not the highest requirement then it is IGBT – all in the same space in the DDP or DQP packages used by ST for Tesla, which allows us to have a flexible module. “The design of the liquid cooling system has been optimised with an AI method for the different variants; perhaps an aluminium cooler for 400 V IGBT, but on the other side with the thermal behaviour for an 800 V premium vehicle, we may need a copper cooler with a baseplate with an optimised fin structure, but all within the same module and baseplate configuration.” The standard two-level inverter is 4–5 cm thick with a DC link capacitor and an EMC filter. The control and gate driver board are produced on a sub-assembly production line. “We would separate out the control and driver board in the future but at the moment we do not see that as necessary,” says Zechmann. “All the variants are flexible for concepts for commercial vehicles as well as off-road and construction,” he says. The sw:SELECT software uses two cores: one with the application software and the second for drivers with dedicated customer interfaces. “We do not change the base core but change the parameters and use the predefined interface to communicate to the customer system,” he says. “There is a lot of AI in the software,” he says. “One of the key factors is the temperature as this derates the drivetrain. You need to identify the hottest spots in the drivetrain. So, we have an AI system that estimates the maximum temperature on the hottest spots. This allows us to go much closer to the limits of the drivetrain,” he adds. POWERTRAINS September/October 2025 | E-Mobility Engineering A modular integrated drive system (Image courtesy of ZF)
The Grid 7 Researchers in Sweden have found that the warning sounds used by EVs can be difficult to locate, writes Nick Flaherty. As electric cars become more common with silent operation, vulnerable road users are encountering more and more warning signals from them. The team at Chalmers University of Technology in Sweden found that one of the most common signal types is very difficult for humans to locate, especially when multiple vehicles are all moving at the same time. The team tested out how well people locate three common types of Acoustic Vehicle Alerting System (AVAS) warning signals from hybrid and electric vehicles moving at low speeds. The researchers’ tests showed that all the signal types were harder to locate than the sound of an internal combustion engine. For one of the signals, most test subjects were unable to distinguish the direction of the sound or determine whether they were hearing one, two or more vehicles simultaneously. Electric and hybrid vehicles meet the requirements set for acoustic warning systems according to international standards. In Europe, plus China and Japan, for example, vehicles travelling at a speed below 20 kph must emit a warning signal consisting of tones or noise, to allow pedestrians, cyclists and other non-car users to detect them. In the United States, warning signals are required from vehicles travelling at speeds of up to 30 kph. “The way the requirements are worded allows car manufacturers to design their own signature sounds. These warning signals are often tested without the complication of background noise. But in a real traffic environment there are usually many different types of sound,” says Wolfgang Kropp, professor of acoustics at the Department of Architecture and Civil Engineering at Chalmers. Existing research has focused mainly on detectability and what is usually referred to as detection distance. No previous studies have investigated what happens when two or three cars emit the same type of signal. “The requirements placed on car manufacturers relate to detection, or detectability, not about locating sound direction or the number of vehicles involved. But if you imagine, say, a supermarket car park, it’s not inconceivable that several similar car models with the same AVAS signal will be moving at the same time and in different directions,” says Leon Müller, a doctoral student at Chalmers. The experiments involved 52 test subjects in a soundproofed, anechoic chamber. Each subject was placed at the centre of the room and surrounded by 24 loudspeakers placed in a ring at chest height. Three types of simulated vehicle sounds were played on the loudspeakers, corresponding to the signals from one, two or more electric and hybrid vehicles, plus an internal combustion engine. One of the signals consisted of two tones, one had multiple tones and one was just noise. The test subjects heard a vehicle warning signal at about 7.5 m away, mixed with pre-recorded background noise from a quiet city car park. When they heard the signal, the subjects had to mark the direction it was coming from as quickly as possible. The signal comprising two tones coming from three vehicles simultaneously was the most difficult, and none of the test subjects managed to locate all the two-tone signals within the 10 second time limit. The test subjects were easily able to locate the sound corresponding to an internal combustion engine because this consisted of short pulses comprising all frequencies – something that is easier for the ear to perceive than a fixed tone at a single frequency. “Naturally, as acousticians, we welcome the fact that electric cars are significantly quieter than internal combustion engines but it’s important to find a balance,” says Müller. “From a traffic safety point of view, it would be desirable to find a signal that’s as effective as possible in terms of detection and localisation, but which doesn’t affect people negatively; something our previous research has shown to be true of traffic noise,” says Kropp. SAFETY EV warning sounds are hard to locate E-Mobility Engineering | September/October 2025 Testing EV warning sounds (Image courtesy Chalmers University)
The Grid Resin-insulated SiC module boosts power density and reduce the thermal resistance by decreasing the area of chips mounted on a module. As the number of chips in the module increases, the number of parameters required for designing the chip layout also increases and the overall optimal design, including the electrical and thermal characteristics, becomes more difficult. However, an optimal design was possible by means of a unique optimisation algorithm using AI. Although Toshiba makes ceramicinsulated SiC power modules, it is also working on resin-insulated SiC power modules for next-generation devices because these have lower cost and longer service life. Toshiba decreased the area of the SiC power semiconductor chips installed in the module, increased the number of mounted chips, and arranged the chips distributed across the entire module. Because the heat dissipation area of the chips is large with radiance shaped toward the heatsink at the bottom of the module, the heat dissipation area increases as the number of chips increases, leading to improved thermal resistance. The AI-based high-dimensional Bayesian optimisation technology automatically optimises large numbers of parameters that would be difficult to explore manually while designing devices such as high-performance power semiconductors and advanced materials. This boosts the performance by seeking out the optimal combination of values through the adjustment of more parameters. For example, when using grid search, a typical optimisation method employed in manual design, if the target performance is evaluated using 10 different values for each parameter, the number of combinations requiring evaluation to determine the optimal parameter values increases from 100 for two parameters (10²) to 10 billion (10¹⁰) for 10 parameters. Manually optimising a large number of parameters is thus difficult and time-consuming. However, the AI enables the optimisation of high-dimensional parameter vectors comprising numerous parameters to data- driven design. Toshiba applied this AI to the automatic design of the power semiconductor, reducing the onresistance by a third compared with conventional search methods based on standard Bayesian optimisation. This resulted in a lower parasitic resistance of 1.23 mΩ, leading to a switching loss of 52.2 mW. A prototype resin-insulated module had 21% lower thermal resistance at 0.040 K/W compared with conventional ceramic-insulated SiC power modules at 0.051 K/W. Used in an inverter, a trial calculation found that the cooling system size could be reduced by 61% from 5371 to 2227 cm3. MATERIALS 8 Toshiba is using resin and AI design techniques to boost the efficiency of power modules for EVs, writes Nick Flaherty. The resin improves the insulation of the substrate in a module with smaller silicon carbide (SiC) power transistors, allowing a smaller inverter with dramatically less cooling. Semiconductor modules use an insulating substrate to prevent electrical interference with surrounding devices, and resin insulating substrates offer lower cost and longer service life with durability against thermal fatigue. However, they also have lower thermal conductivity and higher thermal resistance compared with the ceramic substrates that are in widespread use. A large cooling system is needed to maintain high performance, but this creates the separate problem of increasing the overall size of the module. So, Toshiba used an AI technique to assess the design of the module to increase the thermal dissipation area September/October 2025 | E-Mobility Engineering Resin-insulated power module (Image courtesy of Toshiba)
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10 In-wheel motor power boost MOTORS Orbis Electric has developed a modular in-wheel motor with the performance of a V8 engine, says Nick Flaherty. The HaloDrive is an axial motor that is designed to fit inside a wheel, reducing weight and improving range by up to 20%. It uses a modular, four-part architecture with an injection-moulded plastic stator and a tunable gearset. This provides a torque density of 100 Nm/kg, equivalent to a V8 engine, says Orbis, based in Santa Rosa, California. The in-wheel motor is designed for a variety of e-mobility applications, including commercial transportation, trucking fleets and passenger vehicles, as well as marine systems and aerospace platforms. The technology is an alternative to more common Permanent Magnet Synchronous Motors electric motors. The 50 kg dual-rotor version for battery EVs generates continuous power of 78 kW with a maximum output of 145 kW with peak torque of 5500 Nm and has efficiency of 96%. Versions are available from 200 to 800 V. It includes an integrated lightweight disc brake and electronic parking brake, making use of the inertia of the motor, and is ready for vehicle assembly lines because it also uses a cartridge-type wheel bearing drawn from OEM specifications, says Orbis. The variant for hybrid vehicles has a single rotor and generates 53 kW continuously with efficiency of 93%. Using an in-wheel design saves valuable space in a hybrid that needs to accommodate a battery pack alongside the combustion engine in an existing vehicle platform. Both have diameter of 428 mm, while the dual-rotor version is 132 mm deep and the hybrid single-rotor version is 115 mm deep and weighs 42 kg. The motor can also use nonneodymium magnets to avoid supply chain dependency on the rare earth elements (REEs) used in such magnets and to reduce cost, although performance will be reduced. The motor can be used in various drivetrain positions without requiring structural modifications. As well as in-wheel positioning, the motor can also sit between the engine and the transmission, on the transmission output shaft and on the rear axle. The motor has been piloted by leading passenger vehicle OEMs for in-wheel propulsion systems and in heavy-duty trucking fleets as dieselreplacement generators. In these commercial applications, the electric motor is already delivering significant cost savings, including improving one customer’s fleet fuel efficiency by 61%. One of the emerging applications is using electric motors as generators for electric transport refrigeration units in commercial trucks. Installed on the driveshaft or an axle, the HaloDrive motor converts the truck’s braking energy into cost-saving electricity to power mobile refrigeration. “Our approach with HaloDrive is and always has been about creating a motor that not only meets the immediate electrification needs across a range of industries, but is also compact and efficient enough to position businesses for future energy and sustainability standards,” says Marcus Hays, founder and CTO of Orbis Electric. “This is something our engineering team of EV, aerospace, fabrication and environmental experts has spent years developing. We can achieve exceptional performance while also mitigating risks tied to rare earth materials, ensuring consistent availability and pricing stability.” Orbis Electric is actively seeking Tier 1 production partners for the drive as well as OEMs, fleets and industrial customers. Orbis has previously worked with Volkswagen on a 559 kW prototype using an in-wheel motor design that was completed in August 2024. September/October 2025 | E-Mobility Engineering A lightweight in-wheel motor with 3D printed stator (Image courtesy of Orbis Electric)
The Grid PROTECTING YOUR BATTERY Preserving your peace of mind. Stop thermal propagation with PyroThin cell barriers. Learn more at aerogel.com/PyroThin Aspen aerogels Third-generation e-power powertrain boosts efficiency noise and boosts the efficiency of the engine, particularly at higher speeds. Combined with improvements to engine calibration and sound insulation, vibration is reduced under load. Overall, power is up by 11 kW, at a maximum of 151 kW. The battery capacity is unchanged at 2.1 kWh. The three-cylinder 1.5 litre turbo engine has also been redesigned using a principle Nissan called Strong Tumble & Appropriately stretched Robust ignition Channel (STARC). The ‘tumble’ refers to the in-cylinder gas flow – the way the air–fuel mixture swirls inside the cylinder. By making this flow ‘strong’, Nissan can more effectively mix the fuel and air using the fixed rpm rate. The ‘appropriately stretched robust ignition channel’ is an improved ignition process that reliably burns a more diluted air– fuel mixture at a high compression ratio, improving combustion efficiency that raises thermal efficiency by 42%. A larger turbo brings efficiency gains and allows a 200 rpm reduction in engine speeds during highway driving, contributing to the lower overall noise level. It also means that the variable compression ratio technology used on the previous version has been rendered redundant, helping to reduce size and weight. POWERTRAINS Nissan has launched its thirdgeneration hybrid electric powertrain, combining five functions in one unit, writes Nick Flaherty. The e-power platform uses a petrol engine as a generator for the electric motors with a 2.1 kWh battery. The third-generation design optimises the packaging of the motor, inverter, electric generator and reducer and increaser gear systems. Nissan has also redesigned the combustion engine to increase the fuel efficiency because it can run at a constant frequency. The 5-in-1 powertrain has been designed for more rigidity at the fixed frequency, minimising vibrations at the key resonance points. This reduces cabin The third-generation 5-in-1 e-power unit (Image courtesy of Nissan) PROTECTING YOUR BATTERY. Preserving your peace of mind. Stop thermal propagation with PyroThin® cell barriers. Learn more at aerogel.com/PyroThin by
12 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 CHARGING CPCV algorithm reduces harmonics in EV charging Researchers in China have developed a constant power, constant voltage (CPCV) algorithm that can reduce the total harmonic distortion (THD) in EV charging networks, writes Nick Flaherty. Harmonic distortion is produced throughout battery charging and is not sufficiently addressed by conventional charging algorithms such as Constant Current Constant Voltage (CCCV), say researchers at Hanjiang University in Hubei Shiyan. This harmonic distortion can reduce the efficiency of the power network and reduce the power quality. These non-sinusoidal harmonic currents have the ability to alter the power waveform and cause a number of problems, including higher losses, equipment overheating and interference with delicate loads. Various factors, including the type of EV, the charging infrastructure and the operating conditions might affect the degree of harmonic distortion. To address this, the CPCV charging algorithm dynamically modifies the charging power according to the state of charge of the battery in the vehicle. Compared with conventional techniques, this more efficiently controls harmonic emissions and enhances power quality. The reason for this is that the continuous power supply provided throughout the CV phase may lead to a boost in energy loss, which eventually lowers charging efficiency. CPCV also boosts efficiency by guaranteeing a power factor that is almost constant throughout all charging conditions, maximising energy use. The Grid Dr Nabeell Shiirazee esearchers 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 Higher energy through three-layer electrolyte A new self-extinguishing, solid-state lithium-metal battery cell could allow higher energy densities, writes Nick Flaherty. Conventional, solid-polymer electrolyte batteries struggle to make good contact with the metal electrode, which is necessary to prevent lithium dendrites. These grow with charging cycles and can reduce battery cell performance, and even create a short circuit. A three-layer electrolyte, developed at Daegu Gyeongbuk Institute of Science and Technology (DGIST) in Korea, offers enhanced fire safety and longer life. Each layer has a distinct function: decabromodiphenyl ethane (DBDPE) as a fire retardant; zeolite to boost the electrolyte’s strength; and a high concentration of a lithium salt, lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), to allow more rapid movement of lithium ions for fast charging. The solid-state electrolyte allows the layering architecture, where the middle layer boosts the battery’s mechanical strength, and the softer outer surfaces improve electrode contact, allowing easier movement of lithium ions. Experimental data shows the 4.8 V lithium metal battery cell developed by the research team retained about 87.9% of its performance after 1,000 charging and discharging cycles at a 1 C charging rate. This is a notable improvement in durability compared with traditional batteries, which typically maintain 70-80% of their performance. The battery cell has an initial capacity of 153 mAh/g and can extinguish itself in a fire, significantly reducing the fire risk. March/April 2025 | E-Mobility Engineering September/October 2025 |
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MOVE America Wednesday 24 – Thursday 25 September Detroit, USA www.terrapinn.com/exhibition/move-america Busworld Europe Saturday 4 – Thursday 9 October Brussels, Belgium www.busworldeurope.org Electric & Hybrid Vehicle Technology Expo North America Monday 6 – Thursday 9 October Detroit, USA www.evtechexpo.com The Battery Show North Monday 6 – Thursday 9 October Detroit, USA www.thebatteryshow.com E-CHARGE 2025 Wednesday 8 – Thursday 9 October Bologna, Italy www.e-charge.show ECCE 2025 Sunday 19 – Thursday 23 October Philadelphia, USA www.ieee-ecce.org Automotive Testing Expo Tuesday 21 – Thursday 23 October Michigan, USA www.testingexpo-usa.com The Battery Show India Thursday 30 October – Saturday 1 November Greater Noida, India www.thebatteryshowindia.com Future Battery Forum Tuesday 25 – Wednesday 26 November Berlin, Germany www.futurebattery.eu INDUSTRY The Battery Show and EV Tech Expo North America 2025 returns to Detroit The Battery Show and EV Tech Expo North America 2025 returns to Detroit this October with a technical program built around the engineering challenges keeping battery and EV professionals busy. Over 130 hours of expert education span five tracks covering battery design, solid-state scale-up, supply chain resilience and safety standards, addressing the practical problems engineers face moving from lab to production. For engineers working on next-generation chemistries, the solid-state manufacturing track offers relevant content as the industry tackles scaling these technologies beyond prototypes. Sessions cover manufacturing process challenges, yield optimisation and quality control methods specific to solid-state systems. Battery design sessions address thermal management strategies, cell architecture decisions and BMS integration challenges that impact performance and safety. The expo floor provides hands-on access to equipment, materials and components from over 1300 exhibitors spanning the complete supply chain. Engineers can evaluate precision welding systems, automated assembly equipment, advanced materials and testing instrumentation. This direct access proves invaluable when making sourcing decisions or assessing new technologies for existing production processes. Rapid-fire presentation sessions group 15-minute technical talks by business innovation areas, allowing engineers to quickly scan emerging technologies and identify relevant developments. These often reveal practical solutions to manufacturing problems or highlight cost-reduction strategies successfully implemented elsewhere. The timing also proves strategic as regulatory frameworks increasingly evolve around battery safety, transportation and end-of-life management. Technical sessions decode recent updates to testing standards and certification requirements, providing actionable compliance guidance, particularly crucial as global supply chains adapt to varying regional requirements. Detroit’s automotive engineering expertise makes this event invaluable for vehicle integration challenges. Crucially, networking extends beyond supplier meetings to include access to OEM engineering teams, research institutions and startups developing breakthrough technologies. Registration includes free expo access, with conference passes covering all technical sessions. The EMOB promotional code offers $100 off conference pricing at www.thebatteryshow.com. Diary 14 September/October 2025 | E-Mobility Engineering
The Battery Show North America electric & hybrid vehicle technology expo north america October 6-9, 2025 Huntington Place, Detroit, MI Join industry Leaders at North America’s Premier Battery and EV Tech Event This October in Detroit Proudly celebrating 15 years of innovation and industry leadership In 2025, The Battery Show and Electric & Hybrid Vehicle Techology Expo return to downtown Detroit to celebrate 15 years as North America’s leading event for advanced battery and EV innovation. This flagship expo connects over 21,000 engineers, business leaders and decision makers from across the industry to explore the latest in battery technologies. EV systems, energy storage, components, and more. Attendees will experience four days of technical education (October 6-9) alongside three action-packed days on the expo floor (October 7-9), featuring 1,300+ exhibitors showcasing solutions that are shaping the future of electrification and mobility. Join us at Huntington Place for this milestone edition. Sourcing networking Education informa markets thebatteryshow.com
16 September/October 2025 | E-Mobility Engineering Marlen Valverde, global technical manager ePower and energy storage at H.B. Fuller, speaks to Will Gray on the importance of adhesives, sealants and coatings in EV batteries Developing a special chemistry The development of battery technology is vital for EVs to break further into the mainstream. As the chemistry and architecture of the packs evolve, however, there are increasing demands for advances, quite literally, in the glue that bonds them together – and Marlen Valverde is one of the people at the forefront of that work. “This industry is still in its infancy,” she explains. “We have created a lot of know-how around what makes a successful battery pack, but that’s still evolving, and while the materials that have been supplied until today have been successful, to varying degrees, there’s still a lot more fine-tuning that needs to happen. “The core technology itself, the cell chemistry, is still changing, and that dictates everything else, including the design and geometry. That, in turn, changes the requirements of the adhesive and sealants. So, it is all about active learning and we’re not done yet; it’s still evolving and we’re still trying to react as fast as the battery industry requires.” Valverde grew up amidst the stunning wildlife of Costa Rica, so it was inevitable that her career would be heavily focused on sustainability. However, when she first started out, the EV world was very much in its infancy. So, after earning a PhD in the US, she joined the Renewable Energy Group to work on organic chemistry synthesis for bio-fuels. “I was always interested in learning how to use chemistry as a tool to find ways to do things more efficiently and more sustainably; to reduce environmental disruption and potentiate the use of resources we have at hand,” she recalls. “At the same time, I have always had a passion for cars because my dad instilled in me a love for engines and how they work. “At that time, EVs weren’t a thing and bio-based materials were the future. That was perfect for me, as it involved using readily available materials to create better sustainability than the fossil fuels used in engines – but there was always a question mark over whether the growth of these vegetables should be dedicated to feeding humans or making fuel.” Her work there was cut short, however, owing to the fragility of the US economy, with the company unable to support her young international graduate status. She returned to Costa Rica and began working as a senior r&d scientist for H.B. Fuller, where she was given the dual role of plant chemist and head of architectural and industrial coatings. Marlen Valverde is one of the leading experts in sealants and coatings for ePower and energy storage (All images courtesy of H.B. Fuller)
17 E-Mobility Engineering | September/October 2025 Marlen Valverde | In conversation 20 years inside that car without any problems – no delamination, no movement, no tearing, ripping or detaching – but then one day, when we want to recycle this car, it should pose zero problem for harvesting the component! “That action looks different for every different application, every different customer, every different market. It is important to generate extremely deep knowledge of what we’re trying to do, so that when the material gets formulated, it fulfils the expectations through its life. That is something I have been doing for many years now!” Over time, her role grew into covering other applications within a car – headlamps, exterior trims, under the hood applications. Eventually, she became the technical manager for automotive and transportation and travelled all around the world to better understand the automotive world from many different angles and in many different regions. “These were highly regulated, highly controlled markets and you learn quickly that you cannot do a single change in any single formula without full clear communication,” she explains. “It has to be documented and you have to prove the change is not causing any issues to the performance of the material.” Arriving in the EV space It was in 2020 when her role radically changed following a leadership meeting focused on the growing EV market. Recognising the importance of adhesives and coatings in the battery space, the senior management team wanted to know if the company was aligned and had the knowledge to start formulating the materials needed in the market. “We looked at each other and nobody knew what to answer,” she recalls. “So, I came out of that meeting and one of the vice presidents of the business chased me down and said: ‘Hey, do you want to be that person; to be the scout out there in the market?’ So, soon after that, I became business development manager for the entire electric battery space. “The target was not just for EVs but for everything electric – handheld tools, energy storage systems, vacuum cleaners, lawnmowers, anything with a battery. They basically gave me a map of the United States and said: ‘Go for it! Go find this business.’ It was a daunting task, but at the same it was a privileged one. “I focused on targeting the customers that I knew and had been working with, those I knew already were working on battery projects. I slowly started to get communication with them, build relationships with the key stakeholders in those companies and start learning about the application at the same time as my customers. “We entered this space at a time where everybody else was also learning. So, I helped them learn, they helped me learn, and together we developed the definition of what is important for the performance of a material in this space, and the knowledge required to successfully formulate those materials.” Valverde’s scope involved anything immediately outside of the cell, identifying applications where there was a need for an adhesive material and understanding how it could enable better battery functionality and optimisation. The focus quickly evolved into sealants, encapsulants This wide-reaching remit involved developing materials for metal applications in the marine, architecture and automotive industries and – crucially – gave her an early insight into the regulatory requirements in the automotive industry and how chemical development plants need to operate to supply that market. Into the world of adhesives After almost two years, an internal transfer within H.B. Fuller took Valverde back to the US, where she began working on reactive adhesives for automotive interior trims. The new role brought her focus back onto sustainability, with one of her aims being the reduction of scrap and contamination in the manufacturing process. She was also tasked with trying to increase the amount of bio-based material within the formulations as well as the recyclability at the end of life and how the components can be harvested and reused. These requirements continue to be a priority in her current role – but when it comes to adhesives, recycling efforts bring with them a very unique challenge. “It’s an interesting balance,” she begins to explain. “We have to provide adhesives with the strength to survive Valverde’s work on hot metal adhesives is helping to transform how mica shields and battery cells are integrated into battery packs
18 September/October 2025 | E-Mobility Engineering and coatings as well, to meet the advancing requirements. As the market grew, Valverde became so successful in harvesting all the information and learning what new materials would be needed to meet global demand that the company’s innovation portfolio became vast. It needed managing and she was the obvious choice to take the role, adding it to her ongoing work scouting the market for new opportunities. Developing the next generation One of the biggest influences on the work of Valverde and her team has been changes to battery architecture design. In an endeavour to deliver ever-higher energy density, better battery efficiency and extended range, designers are having to pack increasing numbers of cells into the same space – and that has led to a revolution. “There has been a change from ‘cellto-module-to-pack’ architecture to just ‘cell-to-pack’ designs, skipping the whole module approach,” explains Valverde. “Losing the intermediate metal box protection of the module has had a tremendous effect on the requirements for the adhesives that now bond the cells to the pack. “We now need to create materials that are far more structural and far easier to apply and with the added demand for faster production, a lot of the steps have to happen very quickly. Thousands of units need to be produced per day so there’s now very little time for the adhesive to build up strength, and that has definitely influenced our latest innovations.” In the EV industry, time is money and Valverde’s team is working hard to introduce new materials that can lower costs by reducing the application complexity; reducing the application time; reducing the length of curing needed before the process can move to the next step; or reducing the overall amount of material that is needed. “We want the electrification of transportation to take place and if consumers cannot afford to buy an EV, it is either never going to happen or it is going to happen very slowly,” explains Valverde. “That’s no good for anybody, but making materials cheaper is not always possible, so we try also to reduce the cost of the overall process by making things more efficient. “One good example is our EV Bond 775 hot melt reactive adhesive, which is formulated to be applied in a molten state. You melt it, apply it, and as it cools down and gets compressed between two surfaces, the molecules of the polymer have been deliberately formulated to arrange themselves in a way that immediately starts generating strength. “The ultimate performance still requires the material to fully cure, but for the manufacturing steps, we can design materials that generate enough strength to allow the next process to occur without having to wait for the full curing time. That reduction in process time can achieve big savings for the customers. “We are also working on reducing the number of adhesives required across the whole battery manufacturing process. To do that, we are developing the robustness of materials so they can bond to multiple substrates and under multiple geometries, and that is another one of our main focuses at the moment. “We cannot claim we invented all these new approaches; they are often just chemistry tricks you learn at school and are already in use for other applications, but we connect the dots and make them work at a commercial scale for the EV industry. That’s achieved through lots and lots of formulations and r&d by an extremely talented team of experts.” Into the future Global electrification is not solely consigned to EVs, so neither is the work of Valverde’s team. The company is supporting companies that are developing space rockets, satellites, submarines and weather buoys, among many other applications, and the criteria for the bonding performance and surface materials involved are similar for all. “There are slight differences, but for the most part I would say 90% of the requirements are the same,” says Valverde. “Just that last 10% may change from application to application In conversation | Marlen Valverde Valverde’s team work on a wide range of applications, including thermal management, bonding, sealing and encapsulation technologies
19 E-Mobility Engineering | September/October 2025 – for example, if the battery is going into a military application or it’s being submerged, there are additional requirements such as ballistic strength and corrosion resistance.” Solid‑state batteries are soon to enter limited commercialisation, driven by breakthroughs in ceramic and sulphide electrolytes. These have the potential to deliver two- or three-times higher energy density, dramatically faster charging and enhanced safety owing to the use of non‑flammable solid materials. Meanwhile, second-wave chemistries such as sodium‑ion (Na‑ion) and silicon‑anode enhanced lithium‑ion are also gaining traction, with highly packed cells that promise greater power density, faster charging, low temperature capabilities, higher cycles and lower cost, with some designs slated for production by the end of the year. These new technologies and chemistries, added to improvements in battery management systems with AI‑optimised charging, advanced thermal control and more robust recycling frameworks, are driving a holistic transformation in EV battery systems – and this is all leading to advancements of new adhesive, sealant and coating technologies. Valverde explains: “Safety is a particularly important area. There is an intrinsic issue with the chemistry of battery cells, in that if there’s an error in manufacturing or in the environment of the cell and how it operates, it could reach a situation where it gets overheated – and batteries can do so in a very dramatic and catastrophic way. “As the energy density of batteries increases, the need for zero problems and zero errors increases, so our materials need to provide behaviours and performance that help prevent catastrophic outcomes. That includes flame retardancy, fire-fighting activity, smoke absorption, efficient cooling and many other properties. “If you’re bonding a big heavy cell to a cold plate – which is there to draw heat away from the cell so it never gets too hot to get to the danger zone – we need an adhesive that will create the bond but that does not block that heat transfer efficiency. We need to formulate a material that enables effective heat transfer and we do that in a molecular way. “We have also developed a new dielectric coating that reduces electrical losses to improve efficiency. There are lots of metal structures around the cells and if they touch there will be current leakage, draining the energy of that cell at a moment when it’s not necessary. This coating renders those metal surfaces non-electrically conductive.” As well as advancing the capability of the materials, Valverde is also using past experience to make them more sustainable. She says there is a big pull in the market for adhesives and sealants that are more environmentally friendly and offer long-term recyclability – but, just as she found with the interior trim adhesives, it is not easy to achieve. “There’s a term, ‘on-demand’ bonding, which is all to do with controlling how and when materials join together,” she says. “These are hard technical hurdles, holding components together for 20 years then, one day, clicking your fingers and everything falls apart! It’s one of the most complicated things to formulate – but we’re happy to take on the challenge.” When asked to identify the biggest drivers in modern battery development, Valverde picks out two key areas: the continued use of lithium as the main ion for electricity generation, but at the solid-state level; and a longer-term switch to more abundantly available sodium as the chemical ingredient. “My day-to-day work is focused on formulating for tomorrow and two years from now, not for the longer term, but if I answer as a consumer, I would love to see both those technologies become mainstream,” she concludes. “That would make everything safer and cheaper and open the door for the mass adoption of the electrification of everything. “It’s a slow, step-by-step process and there are many issues that have to be considered, so I will give the scientists in charge of that enough time for them to figure it out! My main concerns today are enabling the reduction of manufacturing costs and improvements in safety – and we are constantly finding more and more ways of achieving that.” Spray-applied dielectric coatings are designed to provide uniform coverage and high production speeds
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