Key advantages and challenges of the eMobility revolution

With the rising popularity of electric vehicles (EVs), electric powertrain technology is rapidly advancing and becoming commonplace in other eMobility applications. Electric powertrains are conventionally present in wheelchairs, scooters, and ride-on children's toys. However, the growing diversity of electric powertrain solutions allows for application expansion and the replacement of conventional internal combustion engines (ICEs) in many consumer and industrial mobility products such as scooters, eBikes, autonomous guided vehicles (AGVs), and light-industrial machinery like forklifts.

This shift towards electric powertrain applications is considered the eMobility revolution. With the expansion come challenges that demand meticulous consideration by engineers to ensure the safety and operability of these solutions. This article looks at the benefits and drawbacks of eMobility and electric power trains in these applications.

What is eMobility?

eMobility, short for “electric mobility,” is a transformative shift towards electrification in transportation and industrial applications. eMobility is growing in popularity given its sustainability, efficiency, safety, and technological benefits over traditional mobility solutions. eMobility devices can be as small as an electric skateboard/hoverboard and as large as marine vessels and industrial equipment.

The concept of mobility extends beyond individual vehicles to encompass broader infrastructure developments, including charging networks, renewable energy integration, smart grid technology, and recycling infrastructure. Consumers, industries, and governments around the world are increasingly embracing and incentivizing eMobility as a key strategy to address climate change, reduce air pollution, and revolutionize the energy sector.

The benefits and advantages of eMobility

Instant torque and responsive performance

Electric drivetrains, a key component of eMobility solutions, can deliver powerful torque with superior acceleration and responsiveness. While this instantaneous torque is commonly associated with higher acceleration, it is also extremely advantageous for superior traction control. These benefits translate to higher performance and safety in applications like forklifts, bicycles, and AGVs.

Reduced noise pollution

Conventional ICE vehicles generate considerably higher noise than similarly performing eMobility solutions. For example, Formula 1 cars generate around 134 dB when racing, which can cause hearing damage, while similar Formula E cars generate only 80 dB, making them roughly as loud as an alarm clock or vacuum. eMobility applications can be highly advantageous in delicate or regulated environments such as construction sites, urban areas, and marine settings.

Energy efficiency

Electric powertrains boast significantly higher energy efficiency than their ICE counterparts. Electric motors can convert more than 85% of their electrical energy into mechanical energy, whereas ICEs convert less than 40% of their chemical energy into mechanical energy. This energy efficiency is especially advantageous in sectors like manufacturing and transportation, where energy expenses are a large portion of operating costs. In other applications, such as rental sharing scooters, energy efficiency is critical to meeting customer needs and providing a full day's worth of transportation on a single charge.

Environmental sustainability

eMobility solutions offer a sustainable alternative to internal combustion engines. For example, traditional two-stroke engines produce very high levels of hydrocarbon exhaust emissions at nearly 5,500 ppm, compared to 4-stroke 850 ppm emissions found in cars. Due to this disparity, nearly 20 years ago, the U.S. Environmental Protection Agency (EPA) enacted stringent restrictions on the emissions of two-stroke engines.

Dirt bikes, ATVs, UTVs, jet skis, mopeds, lawn equipment, and other small personal mobility devices have traditionally used two-stroke engines given their high power-to-weight ratios and low cost. As a result, large pollution issues have become common in developing countries where these devices are more commonplace.

Image: Visible air pollution in Jodhpur’s Blue City related to the abundance of two-stroke motor vehicles

Electric motors offer zero emissions, providing an immediate solution. eMobility solutions can directly reduce the number of pollutant-related deaths and drastically reduce greenhouse gas emissions in these applications, making them a viable environmental sustainability measure around the world.

The challenges of eMobility solutions

Infrastructure limitations

eMobility solutions rely heavily on a vast electrical infrastructure that can support a specific application’s power demand. For small consumer eMobility devices, this demand is largely met via standard home electricity infrastructure. But in applications with large power demands such as manufacturing and mining, eMobility charging infrastructure must be vast and high-powered to meet the industry’s needs/

Limited range and battery charge life

Despite advancements in battery and power management technology, eMobility solutions are limited in range compared to traditional fuel sources. Devices such as marine vessels and machinery may necessitate frequent recharging or larger battery capacities to fulfill operational demands. In smaller engine applications like scooters, wheelchairs, and eBikes, replacement batteries are commonplace.

Luckily, the selection of appropriate battery voltage and chemistry can help optimize the performance and efficiency of eMobility solutions. Different battery chemistries offer an array of parameters such as energy density, power output, lifecycles, thermal stability, specific energy, and weight, which can be used to configure a system design to be application oriented. The figure below showcases various types of lithium-ion battery chemistries.

Isolated DC-DC Converter

For example, NCA lithium batteries (short for Lithium Nickel Cobalt Aluminum Oxide) can be used for certain types of electric vehicles requiring high power loads over time. Other electric vehicles may utilize Lithium Iron Phosphate (LiFePO4 or LFP) given their exceptional thermal stability and long lifespan. Meanwhile, Lithium Titanate (Li2TiO3) or LTO batteries are thermally stable and have an even longer lifespan, making them more common in smaller electric powertrains.

Additionally, proper selection of battery voltage and control hardware can help optimize eMobility performance for specific applications.

Isolated DC-DC Converter

The utilization of high-efficiency, high-power MOSFETs such as NTMFS5C404N from onsemi or IPT012N08NF2SATMA1 from Infineon can further extend the range of eMobility devices, as they have a higher efficiency and power density than traditional silicon-based devices. SiC MOSFETs enable higher-voltage power systems, enabling greater performance and total system efficiency, extending device range and charge life.

Initial cost

The initial investment required for a completed eMobility overhaul, including individual devices and the charging infrastructure, is substantial compared to ICE systems. Long-term operational savings may justify the expenditure, but the higher upfront cost can deter adoption in budget-constrained environments such as low-margin industries and developing nations.

In individual devices, the utilization of higher efficiency components such as the latest low RDSon MOSFETs and LTO lithium-ion batteries can contribute to even higher upfront costs, but this expenditure can be offset by better long-term cost stability and extended life.

Safety and thermal management

In December 2015, the U.S. Consumer Product Safety Commission (CPSC) identified concerns over 12 incidents of eMobility-device-related fires that caused significant damage. All 12 incidents were related to the then-popular ‘hoverboard’ devices, a self-balancing two-wheeled consumer eMobility toy.

Hoverboards quickly became associated with spontaneously catching fire. By July 2016, over 60 hoverboard fire incidents were documented, causing over $2 million in property damage. Surprisingly, the hoverboard fires were not associated with any specific improper use case. They would spontaneously catch fire when not in use, ignite when being charged, or overheat and combust while in use.

As a result, the UL 2272 standard for the Safety of Personal E-Mobility Devices was created to ensure eMobility devices adhere to strict safety standards. Lithium-ion batteries contain highly combustible electrolyte liquids, and eMobility devices must ensure proper thermal management and prevention of short circuits to prevent device fire. Thermal monitoring, cooling systems, and protective circuitry are all imperative to maintain safe operating temperatures and prevent catastrophic failures such as those observed in the hoverboard fires.

Again, the selection of proper battery chemistry and componentry is imperative for guaranteeing device safety. Certain battery chemistries are more thermally stable than others, often at the sacrifice of performance or longevity. Additionally, high-efficiency devices such as SiC MOSFETs can provide lower converter operating temperatures, further reducing the risk of device overheating.

The global shift towards eMobility

The evolving landscape of electric powertrains across a variety of sectors is igniting the eMobility revolution. While traditionally confined to smaller devices, electric powertrains offer a modern solution to consumer and environmental needs across a wide array of eMobility markets, including consumer mobility, industrial machinery, and transportation.

While eMobility solutions offer enhanced performance, energy efficiency, and environmental sustainability, challenges continue to limit adoption. Careful design consideration and collaboration between engineers, consumers, and governments can spur eMobility adoption and limit the environmental impacts of historically toxic devices. By leveraging advancements in battery chemistry, semiconductor technology, and system integration, consumers and industry can propel the transition towards a cleaner, more sustainable future of mobility at a global scale.

See related product

C3M0060065D

WOLFSPEED, INC MOSFETs View

See related product

1317

Adafruit Industries Batteries View

See related product

ENC-180-48

MEAN WELL Battery Chargers View

Are you on the list?

Sign up to receive exclusive offers, product announcements, and the latest industry news.