Understanding EV Range Anxiety

EV range anxiety refers to the fear that an electric vehicle has insufficient range to reach its destination, leaving the driver stranded without a charging station in proximity. This has been one of the initial primary concerns deterring consumers from adopting EVs. The anxiety stems from early electric vehicles’ limited range, the sparse distribution of charging infrastructure, and longer charging times compared to the convenience of refuelling gasoline vehicles.

The automotive industry's evolution is aimed in various directions:

• Lightweighting
• Fast-charge, long-duration lithium batteries
• Higher voltage platforms

Lightweighting

In terms of lightweighting, a development underway since many years in the automotive sector, aimed at increasing efficiency, automakers and Tier-1s are working on possible further applications, as each weight reduction improves the range of electric vehicles. Some companies are working on developing components – such as the audio system – that not only weigh between 30-60% less but also draw 60% less power from the car without affecting performance. 

EVs are considerably heavier than their ICE counterparts vehicles, not only due to the bulky/ heavier batteries but also the heavier structural supports, including the body frame and the battery enclosure. Even though the lightweighting strategy of the ICE vehicles has already been initiated, it should be accelerated to address the outgrowing issues of EVs, such as limited travel range and increased curb weight. Extensive attention needs to be paid to materials selection in terms of substituting metallic and traditional plastics with high-performance lightweight composite materials using glass/carbon fibers.

Fabrications of automotive structural components, including cellular plastics with significant strength and stability, could effectively lead to both lightweighting and cost reduction. Advancing cellular plastic manufacturing using polymer blends/alloys and reinforced plastics could enhance their performance with an effective reduction of their mass. These could be adopted as structural components for EVs. 

Fior Markets reported that the global microcellular plastics market is projected to increase from USD 12,426 million in 2020 to over USD 23,343.66 million by 2028 at 8.2% of compound annual growth rate (CAGR), which indicates a secured supply chain towards this emerging demand.

As the global transportation industry looks for lighter components with higher strength characteristics, sandwich structures are an emerging option for these demands. Sandwich structures receive the benefit of two different mechanical properties from the face sheet and core materials. By adopting satiable core geometries (I, V, O, VF and X panels), sandwich structures provide high strength with a 30–50% weight savings compared to traditional steel applications.

In recent years, 3D printing technology is also receiving increasing investigation within the automotive sector for a wide range of applications, from prototyping and tools to lower-volume parts manufacturing. The advancements in 3D printing technologies led to the ability to fabricate high-precision auto parts, achieve comparable mechanical properties, and fabricate complicated structures not achievable by other polymer manufacturing methods. Moreover, 3D printing technology enables the fabrication of automotive components from pristine, reinforced, and cellular plastics to achieve the desired structural, mechanical, durable and lightweighting properties.

Fast-charge, long-duration lithium batteries

Lithium-ion batteries are among the most popular means of powering electric vehicles and smartphones as they are lightweight, reliable and relatively energy-efficient. However, they take hours to charge, and lack the capacity to handle large surges of current.

Cornell University engineers published a paper, whose lead author is Shuo Jin, a doctoral student in chemical and biomolecular engineering, published in Joule: "Fast-Charge, Long-Duration Storage in Lithium Batteries". 

The researchers pinpointed indium as an exceptionally promising material for fast-charging batteries. Indium is a soft metal, mostly used to make indium tin oxide coatings for touch-screen displays and solar panels. The new study shows indium has two crucial characteristics as a battery anode: an extremely low migration energy barrier, which sets the rate at which ions diffuse in the solid state; and a modest exchange current density, which is related to the rate at which ions are reduced in the anode. The combination of those qualities -- rapid diffusion and slow surface reaction kinetics -- is essential for fast charging and long-duration storage.

Higher voltage platforms

The new developments towards 800V and 900V platforms represent another monumental leap in addressing range anxiety and improving overall EV performance:

• Faster charging - higher voltage platforms enable much faster charging times. For example, vehicles built on an 800V architecture, can charge from 5% to 80% in just about 22 minutes under ideal conditions. This is a stark improvement over the 400V systems used in many earlier EVs, which typically take longer to achieve a similar state of charge.
• Increased efficiency - higher voltage systems can reduce the current for the same power output, leading to less heat generation and lower energy losses. This efficiency improvement means that vehicles can achieve longer ranges on a single charge, directly addressing range anxiety.
• Enhanced performance - the transition to higher voltage systems allows for improved vehicle performance. The higher voltage allows for more power to be transmitted to the vehicle's motor(s), which can translate into faster acceleration and, in some cases, higher top speeds. Additionally, these platforms can provide greater flexibility in vehicle design and architecture. For example, they enable more efficient integration of regenerative braking systems, which convert a vehicle's kinetic energy back into electrical energy, further extending its range.

Addressing Infrastructure Challenges

Charger anxiety is the sinking feeling electric car owners experience when arriving at a charging station only to find it is out of order — or there is a long queue to use the only functioning charger. As electric vehicle sales continue to grow, the number of broken fast chargers at any one time is a major problem, as charger anxiety is particularly salient in regional areas where charging infrastructure is further apart.

While the shift to 800V and 900V platforms represents a significant advancement in EV technology, it also poses challenges for the existing charging infrastructure. To fully leverage the benefits of these high-voltage systems, the development of compatible charging stations is essential. This necessitates considerable investment in upgrading current EV charging infrastructure to support faster charging speeds and accommodate the electrical grid's demands.

Current EV charging stations, predominantly designed for 400V systems, cannot fully exploit the fast-charging capabilities of the newer high-voltage vehicles. Thus, there is a growing demand for the development and deployment of high-power charging stations that can deliver the higher voltages and currents required by 800V and 900V EVs. Moreover, these advancements necessitate innovations in battery technology and thermal management systems to safely manage the higher power levels and ensure the longevity of the vehicle's battery pack.

The adoption of 800V and 900V platforms represents a pivotal shift in the EV industry, promising to significantly reduce charging times, enhance efficiency, and improve vehicle performance. As automakers continue to innovate and invest in these technologies, and as infrastructure evolves to support them, the future of electric mobility looks increasingly promising. Overcoming the technical and logistical challenges will be key to fully realizing the potential of high-voltage EV platforms and ensuring their widespread adoption.