A bitter cold stroke in Chicago forced electric vehicle drivers (EV) to queue for hours in the charging stations last month; Some even found themselves blocked on the death of their battery as they were waiting in the queues. The rechargeableLithium-ion batteries that feed most electric vehicles allow you to be difficult in the cold, so scientists and car manufacturers around the world are busy rushing for solutions. These include more sophisticated IT models to ensure advanced performance, as well as more durable batteries that advance cars – and their safe drivers – whether it is freezing or burning on the road.
Such upgrades are aimed at approaching significant obstacles to the promised revolution in electric vehicles. Biden administration is working on the increase in the property of electric vehicles in an ambitious thrust to reduce greenhouse emissions, and the president hopes that electric vehicles constitute half of all new vehicles sold in the United States by 2030 (compared to around 8% of car sales in first half of 2023). But recent accidents, such as the stalling of cars in Chicago, show how current EV technology could bend as the future time becomes even more extreme: climate change continues to raise global temperatures, but this disturbs the models that have long regulated the weather of the planet – so that global warming cannot introduce worse cold buttons.
“The extreme cold presents security risks for the burden of batteries,” explains Paul Gasper, scientist of the staff of the National Renewable Energy Laboratory electrochemical storage group. Scientists generally consider lithium -ion batteries to be used in a relatively narrow temperature range – between 32 to 140 degrees Fahrenheit (zero at 60 degrees Celsius), but estimates vary. When it reaches 20 degrees F (minus seven degrees c) outside, an average motor beach of an EV drops by 12% compared to its beach at 75 degrees F (24 degrees C), the American Automobile Association found in 2019. To understand why, we must dive into chemistry which feeds an EV battery.
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Temperature check
When the EV batteries are enriched, the lithium ions carrying loads cross a liquid electrolyte from one end of each battery cell to another (between the positive cathode and the negative anode). Then, as cars sits the stored energy of the battery during the discs – the ions turn in the opposite direction. If a battery cools (in a cold snap, for example), the liquid highway between the anode and the cathode thickens, slowing down the ions. This means that the cooler batteries can take longer to load, and they can waste this load earlier than to softer temperatures.
Load cars when it is less than 32 degrees F can cause an accumulation of lithium ions on the surface of the anode because the particles cannot move fairly quickly. These clusters of ions, called veneer, can cause a short-circuit of the battery and even trigger an explosion. (However, electric cars take fire relatively rarely compared to gas cars, and researchers study conceptions for the batteries that go out.)
In addition to that, the entire EV has overtime to warm things up. Its thermal management system, which regulates the temperature of the battery, electric motor and other components, also drains the load. And when a driver turns on the heat of the cabin, the battery must feed the HVAC system and other devices such as define and seat heater. Gas cars with internal combustion engines also suffer from cold; Their fuel economy decreases by around 15% to 20 degrees F, compared to what they would obtain at 77 degrees F (25 degrees C), according to the US Energy Ministry. But the equivalent loss for an EV can reach 39% to 20 degrees F.
Extremely hot days can also affect the performance of an electric vehicle. Higher temperatures accelerate travel ions, and at a point, this triggers a cascade of involuntary chemical reactions which can degrade the components of the battery – including electrolyte – during the life of a car. When external temperatures reach 95 degrees F (35 degrees C) and drivers increase air conditioning, the practice may decrease by 17%, according to the AAA ratio.
AI adjustment
DIY with car software can better benefit from the batteries that are already on the market. Teslas and other electric vehicles with sophisticated computers use complex artificial intelligence models to ensure that batteries work safely and efficiently; These AI programs analyze data from temperature and voltage sensors to prevent battery overload and predict how far a car can lead to its remaining load. Teslas also has a characteristic called preconditioning, in which cars heat or cool their battery at the appropriate charging temperature. But these models need some improvements, says Gasper.
On the one hand, they could be better personalized to account for the health of a battery because it degrades over time, he explains. He also thinks that AI models could push cars to succeed in a wider range of temperatures (by distributing liquidity or by controlling fans, for example) without putting risks to the car or the driver. As these models improve, we could better trust electric vehicles to safely manage the battery “in its widest possible operating window”, explains Gasper.
For the moment, AI models can only give drivers only an approximation of the current load and health levels of a battery, explains the electrician engineer I. Safak Bayram, an associate professor at the University of Strathclyde in Scotland. This is why electric vehicle drivers often experience sudden drops in the estimates of their vehicle guard, he adds. In Chicago in January, an Uber driver was blocked even if his car showed that there were 30 miles stayed on his battery.
But the smarter models of AI can only push cars so far, says Gasper. Putting electric vehicles to the next level in sustainable extreme temperatures will also require progress in battery technology itself.
Best batteries
Scientists try several strategies to make batteries more resilient with bad weather. A promising method is to improve electrolyte. Zheng Chen, scientist and materials engineer at the University of California in San Diego, and his colleagues have created a new electrolyte that worked well in laboratory tests at temperatures as low as –40 degrees F (–40 degrees C) and 122 degrees F (50 degrees C), according to a study by researchers published in 2022.
The team has reached there by mixing a lithium salt with a solvent called dibutyl ether, which easily passes around lithium ions and remains a liquid even at subzero and super -fectic temperatures. Although the recipe is promising, it is difficult to say if it will work on a large scale with commercially available battery parts. And this type of formula is probably not a unique solution: car manufacturers use a variety of materials in lithium-ion batteries, which they are continuously modifying to follow technological progress and guarantee, for example, more affordable components or a longer range. No metal solvent or salt can comb out with all battery materials on the market, says Chen.
Although it is difficult to find electrolytes and other materials that excel in real variable conditions, Gasper says that artificial intelligence can help accelerate the discovery process. Researchers have programmed robots inspired by technology that the pharmaceutical industry already uses the discovery of drugs to test candidate substances.
Some experts believe that self-heating batteries could be another way to help electric vehicles beat the cold. In 2018, Pennsylvania State University scientists announced that they had created such a battery by incorporating a nickel sheet that intercepts the electrons when the battery dives below the room temperature. The captured electrons warm aluminum foil, heating the whole battery in turn. Scientists say that could allow fast load batteries even at temperatures as low as –58 degrees F (–50 degrees C). Other approaches, such as the car’s electric power operating pulses, can also warm the batteries for faster load in the cold.
But EV engineers face a dilemma that they call “and the problem”: it is difficult to design a battery that works effectively in a range of environments And Remains affordable and lasting. “In a way, we try to balance costs, performance and security,” explains Chen. Car manufacturers can approach these factors differently depending on their priorities. Some, for example, assess higher performance than affordability and can integrate more expensive battery materials. This is why the more expensive EVs tend to have higher ranges of kilometers.
In the end, it may be preferable to adapt the battery conceptions for specific climates across the country and the world, suggests Gasper. Drivers in climates closer to the posts would use batteries suitable for cold. Heat resilient batteries are particularly important for people living in equatorial regions. There, faster chemical reactions, stimulated by heat, can degrade batteries – potentially leading to higher long -term EV costs in regions where income is lower than the global average. “It’s a problem of economic justice,” says Gasper. The industry is not yet there, but it is a problem that EV experts know that they must solve.
