Author:
Mark Patrick, Director, Technical Content, EMEA, Mouser Electronics
Date
11/20/2024
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Considering all factors, the automotive industry has been remarkably fast in transitioning towards electrification. Despite its incredible size, long-established processes, and relatively lengthy R&D cycles, which can all hinder progress, manufacturers across the globe have rapidly launched complete electric vehicle (EV) model ranges. Following the launch of the Nissan Leaf in 2011, which was the world’s first truly mass-produced EV, the number of fully fledged EV models available for sale surpassed 450 in 2021. From 2015 to 2021, the compound annual growth rate (CAGR) for new models reached an astonishing 34%.
As a whole, and even in the light of challenging global markets, the passenger EV market has been successful. But despite the significant success of passenger EVs, the commercial sector, which includes large or heavy goods vehicles (LGVs/HGVs), has not progressed quite as quickly.
Research indicates that while medium- and heavy-duty vehicles make up just 4% of the global vehicle population, they account for a staggering 40% of emissions produced by road transportation. This emphasises the significance of this sector, highlighting the need to prioritise its development and successfully integrate commercial electric vehicles to attain a sustainable future.
Challenges Faced by Commercial EVs
In 2022, EV passenger cars accounted for 14% of new sales, while electric trucks only made up 1.2% of total truck sales in the same year. Vehicle complexity is arguably one of the key differences between the passenger and commercial EV markets that can account for some of this disparity.
At the core of commercial transportation are HGVs. Generally characterised as vehicles weighing more than 3,500kg, HGVs encompass a wide variety of vehicles, including articulated lorries, tankers, and specialised vehicles like logging and concrete-mixing trucks. The vehicles can have between two and six axles and often need to interact with larger equipment, such as loading systems and trailers, while covering hundreds of thousands of miles every year. In addition to larger HGVs, there are also smaller vans and specialised last-mile delivery solutions, all of which are crucial in modern distribution and haulage networks (Figure 1).
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Figure 1: An example of the types of commercial vehicles available
These vehicles require larger and more powerful batteries to propel heavier loads, which not only raises the cost but also adds to the design challenges of these vehicles compared to their passenger counterparts. Additionally, the current limitations of battery technology pose significant challenges for the cargo capacity of commercial vehicles, with battery weight impacting the total capacity.
Building charging infrastructure for electric trucks is also significantly more complicated and costlier than passenger electric vehicles. The requirement for higher-performance charging stations for trucks presents several design obstacles related to safety and performance.
The European Alternative Fuels Observatory (EAFO) states that there are currently over 550,000 public charging points in Europe as of 2023. However, the European Automobile Manufacturers’ Association (ACEA) predicts that by the end of 2025, only 40,000 charging points will be available for medium- and heavy-duty trucks. To support the expansion of the electric truck network, this number needs to increase to 270,000 by 2030.
Overcoming the Technical Barriers
Like early passenger EVs, electric trucks' limited range is a significant obstacle, primarily attributed to a disparity in energy density. The density of diesel fuel is approximately 12,500Wh/kg, whereas an average Li-ion cell has a density of about 300Wh/kg. Even though electric vehicle powertrains are more efficient than diesel internal combustion engines, which typically have a thermal efficiency of around 40%, this alone is insufficient to compensate for the extra weight carried for the same energy output. Moreover, this added weight negatively impacts the vehicle’s range and necessitates increased engineering considerations for suspension and tires.
Solid State Batteries
One change that could revolutionise EV trucks is the use of solid-state batteries. A standard Li-ion cell consists of two solid electrodes (a cathode and an anode), a central separator functioning as a mechanical barrier, and a liquid Li-ion electrolyte (see Figure 2 for a typical EV battery pack).
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In contrast, a solid-state battery replaces the separator and electrolyte with a solid ceramic or polymer substrate. This solid substrate successfully separates the cathode from the anode, which usually consists of pure lithium.
The altered structure, combined with the inclusion of a pure lithium anode, leads to substantial improvements in energy densities, reaching theoretical levels as high as 11kWh/Kg; but realistically, 1kWh/Kg is a more attainable value in the foreseeable future. By surpassing the capabilities of current cells, solid-state batteries could achieve a weight reduction of up to 30% while maintaining the same capacity.
By improving the energy density of the battery pack, vehicle designers can achieve smaller pack sizes, increase the payload capacity, or extend the vehicle’s range. For many cost or performance-limited operations, this upgrade in performance could allow a switch to electric vehicles.
For the past few years, small-scale solid-state batteries like the TDK CeraCharge Rechargeable Solid-State SMD Battery have been available on the market, and many automotive analysts have suggested that solid-state solutions will enter the market from 2025 onwards. In line with this projection, Toyota has recently announced its plans to produce vehicles with solid-state batteries starting in 2025. These vehicles will feature 700km ranges and charge in just 10–15 minutes.
Fast Charging Networks
One potential solution to tackle the problem of extended stop times is the Megawatt Charging System (MCS). The internationally recognised MCS standard is governed by CharIN, a consortium established by prominent automotive authorities from around the world. MCS is an all-encompassing initiative designed to develop and produce standardised, safe, and high-performing chargers. The standard mandates elements such as a single conductive plug capable of up to 1250VDC and 3000A, vehicle-to-everything (V2X) Ethernet communication, and uniform charging port locations on vehicles.
Truck manufacturer MAN has estimated that charging via MCS could be as quick as 10 minutes—a significant improvement over current technology. MCS is mainly concerned with commercial vehicles, but it can also be adapted for buses, aircraft, and other large electric vehicles that can handle a charge rate above 1MW.
Faster charging speeds can also decrease the requirement for multiple charging stations at busy transport hubs, as trucks can spend less time charging and more time on the road. MCS is still in its early stages and requires high-performance components to operate safely, but stations across the UK and mainland Europe are opening this year.
Battery Swapping
China continues to hold a leading role in the manufacturing and distribution of electric trucks. In 2022, around 52,000 electric medium- and heavy-duty trucks were sold in China, representing 85% of global sales. This growing prevalence of electric trucks is accompanied by a simultaneous expansion of infrastructure, offering valuable insight into potential implementation strategies in other regions.
For example, battery swapping is gaining traction in China, with a fully automated process that takes 3–5 minutes. Robotic arms detach and extract the battery packs from the truck's cab, replacing them with freshly charged ones. The depleted pack is then connected to a rapid charger and recharged. This advancement greatly improves battery charging efficiency, surpassing even the fastest truck chargers.
According to the International Council on Clean Transportation (ICCT), initial assessments show the infrastructure's success. However, its main focus has been on assisting the functioning of electric trucks utilised for short-distance tasks in ports, mining locations, and urban logistics. These trucks are commonly equipped with either a 141kWh or 282kWh lithium iron phosphate (LFP) battery and have an average trip distance of less than 100km. However, obstacles remain before battery swapping can be widely commercialized. The main challenge lies in the absence of standardised battery packs and the substantial expenses involved in establishing these stations, with the ICCT estimating the cost of setting up a battery-swapping station in China to be approximately US$1 million.
Conclusion
The automotive industry's swift transition to electrification, particularly in the passenger EV market, showcases remarkable progress. However, the slower adoption of electric commercial vehicles underscores the pressing need for widespread and collaborative action to overcome technical barriers and bridge this gap—an area where the electronics industry will play a critical role.
From enhancing battery technology with solid-state advancements to developing fast-charging networks like the MCS to exploring innovative solutions such as battery swapping, high performance and standardised electronic solutions are required. Collaboration among automotive manufacturers, electronics engineers, policymakers, and stakeholders is essential to accelerate the development and deployment of electric commercial vehicles. By prioritising research, investment, and cooperation, the automotive industry can achieve a sustainable future where commercial EVs play a significant role in reducing emissions compared to the diesel vehicles of today.
