A bitter cold snap in Chicago, an extreme heatwave in Phoenix, a severe hurricane in Miami — these weather extremes are concerning weather experts more and more each new day. They also highlight the growing challenges faced by electric vehicle (EV) owners and manufacturers.
A record 1.2 million U.S. vehicle buyers chose to go electric in the past year, representing the fastest-growing car sales category. While sales continue to rise, some consumers are deterred by the lack of charging infrastructure that remains a work in progress. Now adding to their angst is a so-called temperature “range anxiety,” defined as EV’s ability to operate in unique seasonal conditions.
All cars lose efficiency in extreme weather; that’s nothing new. However, EV owners face significant challenges in cold temperatures, impacting both performance and consumer perception. Understanding and addressing the impact of extreme temperatures on EVs is crucial for the continued growth and adoption of electric vehicles in diverse climates.
Cold weather challenges
In very cold weather, EVs face significant challenges, primarily affecting battery efficiency and resulting in range loss. Lithium-ion batteries, the cornerstone of most EVs, are designed to operate efficiently within a specific temperature range between 32° F and 140° F (0 to 60° C). Severe cold can slow the chemical reactions required to generate energy, causing the electrolytes to thicken within the battery cells and decreasing both capacity and discharge rate. This leads to reduced mechanical stability and an increased risk of sudden failure. Internal components, such as the separator that prevents the anode and cathode from coming into contact, can become brittle and compromised.
While lithium batteries technically don’t freeze, freezing temperatures can affect the intercalation rate of lithium ions, resulting in a reduction in overall performance. The transfer of lithium ions in and out of the battery slows and decreases the power output. Lithium-ion alloy plates form on the anode surface, hindering current flow and drastically reducing battery capacity. Charging the battery in cold weather further compromises these chemical reactions, causing rapid plating that punctures the separator and damages the battery.
In addition to the impact on battery chemistry, several factors sap range in cold weather. Increased energy is needed to run the cabin heater, seat heaters, defroster and other accessories that combat the cold weather inside the car, diminishing overall efficiency and EV performance.
Examples of range drop data in cold weather include:
- CAR Magazine said that the Honda E's range dropped by about 10% to 15% in winter, while more robust models like the Tesla Model S experienced a reduction of around 16.4%.
- At 20° F (-7° C) with the HVAC system powered on, an EV’s average driving range can drop by 41%, according to the American Automobile Association (AAA). This means for every 100 miles of combined urban/highway driving, the range at 20° F would be reduced to 59 miles.
- Recurrent Auto said that many EVs can lose between 30% to 40% of their range in extreme cold.
- In recent Consumer Reports testing, it was found that short trips in the cold, with frequent stops and the need to reheat the cabin after a parking pause, can reduce up to 50% of the range.
Severe cold can slow the chemical reactions required to generate energy, causing the electrolytes to thicken within the battery cells and decreasing both capacity and discharge rate in EVs. Source: Tricky Shark/Adobe Stock
Future innovations and adaptations
Controlling weather and extreme temperatures may not be possible, but scientists are trying to make EVs more weather resilient. A host of promising trends and technologies aimed at green energy solutions are accelerating, focusing on ways to guard against reduced range and prolong EV battery life.
Electrolyte design
Improving lithium-ion batteries involves innovative approaches to electrolyte design, aiming for high energy density, fast charging and a wide operating temperature range. By using small-sized solvents with low solvation energy, advanced electrolytes can enhance lithium-ion transport and create an inorganic-rich interphase, overcoming the limitations of current electrolytes.
Heat pump standards
More recent EV models use heat pumps to warm the cabin. Inside a heat pump’s compressor, liquid refrigerant is pushed through an expansion valve, transforming it into a gas. The refrigerant becomes extremely cold, and the air warms more than the refrigerant. Since heat passes from warmer to cooler areas, the warm air flows into the car’s interior.
ZF, a German electric motor manufacturer, has developed a propane-driven heat pump that shows promise in extending electric vehicles’ cold weather range by one-third. In addition, it can cool the car’s cabin with its hermetically sealed R290 refrigerant circuit that controls the car’s inverter, motor, and charging components with twin water coolant circuits.
Battery upgrades
Researchers have created an alternative to water-based liquid electrolytes for energy transfer into a vehicle. Using a new active material, multi-electron heteropoly acid H6P2W18O62 with a low freezing point and high conductivity achieves a higher power density and stability without decay.
Since solid-state batteries use solids rather than liquids to generate energy, they are more dependable in cold weather. Both Volkswagen and Toyota have developed production-ready solid-state EV batteries. The Volkswagen battery will have an 80% range advantage over lithium-ion EV batteries and retain 80% of its capacity after 800 charging cycles. It can function at temperatures as low as -30° C and charge faster than lithium-ion batteries. Even better, it presents no safety risk since the battery is non-combustible.
Although EV enthusiasts will have to wait until 2027 to purchase a vehicle with a Toyota solid-state battery, it looks well worth the wait. This battery is more resistant to cold, has a 745-mile range, and charges in 10 minutes. It will weigh about half that of a conventional lithium-ion battery, making it safer in an accident.
Practical tips for EV drivers
There are an array of practices that current owners can use to minimize EV degradation in the face of extreme temperatures and weather patterns.
Preconditioning
Preconditioning is one of the lesser known but genius features of EVs, offering several practical benefits.
Whether it’s a freezing winter morning, preconditioning allows a driver to pre-heat the cabin before starting a journey. The feature can be activated through the infotainment system or a connected smartphone app, allowing prescheduling that mirrors an owner’s driving behavior. While the EV is plugged in, electricity is drawn from the mains, not the car's battery, so there is no impact on the driving range and the car starts out with a fully charged battery.
Preconditioning can also help to maintain lithium-ion battery health. By warming the battery to its optimal temperature in extreme environments, using power from the mains, battery cells are preserved, battery life is prolonged, and range is maintained. Advanced EVs already feature systems that automatically heat or cool the battery on the move, ensuring it stays within the ideal temperature range for optimal performance.
Battery recycling
An EV will typically retire when the battery is at about 70% to 80% of the original rated capacity. A recent study found that 71% of Americans are concerned about used EV batteries ending up in landfills. In fact, EV recycling is already profitable and capable of recovering more than 95% of the key minerals.
If in good condition, the battery can be removed from an EV and reused for other purposes like stationary energy storage prior to recycling. Steel, copper and aluminum scrap metal usually go into a national metals-recycling program. The cells themselves are most highly prized for their lithium, cobalt, manganese, nickel, and aluminum and can be ground up, purified and reused.
Additionally, tinkering with car software can take better advantage of the batteries. Teslas and other EVs with sophisticated onboard computers use complex artificial intelligence models to ensure safe and efficient operation by analyzing data from temperature and voltage sensors to prevent overcharging and predict driving range based on remaining charge.
Conclusion
Extreme weather of all kinds is becoming the new normal and is leading to EV performance concerns. Cold weather slows the chemical reactions within lithium-ion batteries, reducing capacity and decreasing range by up to 50% in severe conditions.
Despite these concerns, strides are being made to enhance EV performance in these extreme conditions. Innovations in heat pump technology, advanced liquid cooling systems and new electrolyte designs are improving battery resilience and efficiency. Preconditioning features and AI-driven battery management systems are helping to mitigate weather impact and preserve battery health and range.
By continuing to innovate and invest in these technologies, the future of EVs looks promising, ensuring they remain a viable solution for sustainable transportation in diverse climates.
About the author
Emily Main holds a J.D. in Compliance Law and a BS in Telecommunications. With extensive experience in the intersection of technology and law, Main has contributed to numerous publications and conferences, exploring technical challenges, innovations, trends and applications. Passionate about communication and networking, she is dedicated to sharing the latest advances in the field with a professional engineering audience through engaging and informative articles.
