As impressive as the Kia EV9 is, a growing number of owners are experiencing serious battery pack issues and enduring long waits for repairs. It will be a huge concern for Kia, particularly given that several other EVs from the broader Hyundai Group have also suffered serious powertrain-related faults in recent years.

Reports from EV9 owners have been swirling online since at least last year, and a UK writer from The Verge, who just so happens to own an EV9, has experienced them firsthand. It started with a small issue, where the 12-volt battery was drained, and he was unable to unlock the car. To get it up and running, he had to access the frunk manually and then hook up a booster to the battery. As it turns out, this fault would soon be the least of his worries.

Review: Kia’s 2026 EV9 Earth Gets The Hard Part Right And Stumbles On The Obvious One

Several weeks later, he says the SUV’s battery would suddenly jump from 82 percent to 100 percent charge when plugged into his home AC charger. The EV’s estimated driving range at 100 percent also plummeted. After purchasing an OBD-II scanner, he discovered that when the Kia displayed 100 percent charge, it was actually only holding 71 kWh, despite having a 99.8 kWh pack. The scanner revealed that some of the pack’s 38 individual modules were dead.

Long Waits For Battery Replacements

A Kia dealership soon verified the issue and confirmed the SUV would need to have the high-voltage battery pack replaced. It’s been entered into Kia’s battery repair program, available through the eight-year warranty for the batteries in the UK, but there’s no clear timeline for when it will be repaired.

The Verge writer says he’s spoken with more than a dozen other EV9 owners in the country who have had similar problems, and some have been unable to continue driving their vehicles while waiting for a new battery. He says at least one has seen their EV9’s range drop to just 30 miles (48 km). Numerous owners in the US have also complained about battery pack failures, indicating this could be a global issue.

Widespread Faults Across Hyundai’s EV Lineup

For years, EVs from Hyundai, Kia, and Genesis have also suffered failures of the Integrated Charging Control Unit (ICCU). The automaker stayed quiet about the problem for a long time before finally acting in 2024, recalling every e-GMP-based EV sold in the US. That didn’t resolve things. Owners continued reporting faults, and Hyundai eventually extended warranties for electric vehicles with ICCU-related problems.

At this stage, no recall has been issued for battery pack failures in the EV9. However, if more owners start experiencing problems and these reports receive greater media coverage, the South Korean car manufacturer may be forced to act.

Another U.S. electric vehicle battery plant is on shaky ground as local EV demand keeps sliding. This one is the massive facility GM and Samsung have been building near New Carlisle, Indiana, and its future is now anything but certain.

The $3.5 billion plant was announced three years ago with initial plans for it to produce nickel-rich prismatic batteries. GM anticipated the site would initially have 30 GWh of capacity, meaning it could produce battery packs for up to 300,000 EVs annually. Capacity was then supposed to ramp up to 36 GWh.

Read: GM’s EV Dream Plant Is Now A Gas Powerhouse In The Making

The problem is what’s happened to the market since. With the Trump administration killing off the $7,500 federal EV tax credit, U.S. demand has cratered, and it’s getting harder for automakers and tech firms to justify writing checks this big for plants of this size.

GM has confirmed that construction of the plant will be paused. In a statement to Detroit News, GM spokesperson Kevin Kelly said: “Construction of the battery cell plant in New Carlisle, Indiana will be paused to align production capacity with current demand. GM and Samsung SDI will communicate plans for the site at a future date.”

The plan, for now, is to finish the building’s exterior as quickly as possible. However, after that, the future of the site remains unclear.

GM’s EV Mistakes

It’s possible the car manufacturer could completely withdraw from its joint venture with Samsung, which is exactly what it did in late 2024 when it pulled out of its partnership with LG Energy Solution on a Michigan battery plant. GM reportedly sold its stake to LG for $1 billion.

An alternative is for GM and Samsung to remain partners and instead manufacture more common lithium-iron phosphate batteries at the site.

If GM pulls out of its joint venture with Samsung, it’ll come at a cost. The company has already revealed it took up to $8.7 billion in EV-related charges and write-downs in 2025, and the money invested in the Indiana plant could be yet another misstep in its EV strategy. The site was supposed to employ up to 1,600 workers and initially set to set producing battery cells this year, although this was later delayed to 2027 a couple of years ago.

Despite regional variability in climate, electricity sources, congestion, and the wide variation in individual driving patterns, electric vehicles generate less greenhouse gas emissions and do not cost more than comparable gas-powered vehicles for drivers and vehicle fleet owners in most parts of the United States, according to a new study by MIT researchers.

The team’s approach captures many key factors that contribute to regional and individual differences in the life-cycle emissions and ownership cost of electric vehicles, including meteorological data, the distance and duration of trips, and fuel prices.

To paint a fuller picture of emissions and costs than was previously available, the researchers sourced data from thousands of U.S. zip codes and drilled down to the level of individual drivers within those locations. Their study considers time-averaged fuel prices so as not to be overly influenced by fluctuations in prices at any one point in time. They finalized their analysis at the end of 2024 and early 2025.

Their results indicate that a person’s driving behaviors can matter as much as regional factors like the local electricity mix when it comes to the emissions savings of an electric vehicle, compared to a similar gas-powered vehicle. In most locations, a battery-electric vehicle reduces emissions between 40 and 60 percent, with larger impacts in urban areas. 

They also found that colder climates do not reduce overall emission benefits as much as some media reports assume.

The researchers utilized this detailed analysis to update a public tool they previously developed, carboncounter.com, which enables individuals to compare the life-cycle emissions and total ownership costs of nearly any car on the market. A new version of carboncounter.com is also being released today.

“There are a lot of statements being thrown around, like that electric vehicles don’t reduce emissions very much in cool climates, and we wanted to analyze these factors systematically and evaluate these statements against one another simultaneously. Rather than simply asking, ‘Are EVs better?’, this paper helps answer ‘better for whom, and under what conditions?’” says Marco Miotti PhD ’20, a senior researcher at ETH Zurich who completed this research while a graduate student in the Institute for Data, Systems, and Society (IDSS) at MIT. 

He is joined on the paper by senior author Jessika Trancik, a professor in IDSS. The research appears today in Environmental Research Letters.

A holistic approach

Many prior studies that compare emissions and costs of electric vehicles (EVs) to combustion-engine vehicles cover a few factors, like the amount of renewable energy in the grid and how gas prices impact affordability, Miotti says.

“To our knowledge, there have been few efforts so far that bring all these factors together. But if someone wants to buy a car and have a better understanding of the factors that affect emissions and costs, this holistic approach is important,” he adds.

The researchers focused on two types of EVs: battery-electric vehicles, which only operate on electricity, and plug-in hybrid electric vehicles, which also have a combustion engine that works in tandem with the battery to optimize fuel savings.

The team expanded and improved a set of previously developed vehicle cost and emissions models to incorporate a wider variety of factors and data types.

For instance, they refined an existing model that estimates energy use and gas mileage so it could capture more nuances of local climate variability. 

“But the real effort was not just in extending these different models, but in bringing together all these different data and making them work with the models in a consistent manner,” Miotti says.

The team sourced data on a wide variety of factors for each U.S. zip code, such as typical drive cycles, the amount of traffic, local gas and electricity prices, makeup of the regional electricity mix, meteorological profiles, and more. They used statistical approaches to amalgamate different types of data. 

For example, the team used a probabilistic matching technique to combine data on how often people drive, which was drawn from nationwide travel surveys, with more detailed GPS data that includes factors like drivers’ acceleration patterns and the distance they usually drive on each day of the week.

The researchers designed their analysis to focus on the spatial picture of emissions and costs, based on U.S. zip codes, while simultaneously considering the impact of the size and features of each specific vehicle model.

“At the end of the day, it’s the vehicle and fleet owners who make decisions about vehicle purchases. So, we wanted to make sure to consider their wide-ranging individual perspectives rather than simply performing a region-by-region comparison,” says Trancik.

Lower emissions, comparable costs

In the end, their modeling framework revealed that all factors they analyzed matter about equally in determining emissions-reduction potential of EVs compared to internal combustion vehicles. 

EVs reduce emissions the most in areas with a cleaner electricity mix, denser traffic, higher annual travel distances, and a mild climate, in decreasing order of importance. In each area, emission reductions increase for drivers who drive more often, drive larger vehicles, and are more frequently stuck in traffic. 

In a colder area like North Dakota, fuel economy of battery-electric vehicles might be reduced by as much as 50 percent on a particularly frigid night, but the effect on annual emission benefits is minimal. 

“We even did a sensitivity study to see if the range is reduced in very cold climates, and we found that, even in the most unfavorable conditions, EVs still reduce emissions by a substantial amount,” Miotti says.

On the cost side, the models show that, in most places across the U.S., EVs are competitive with comparable combustion-engine vehicles in terms of lifetime ownership cost, even without clean vehicle tax credits. And in areas where electricity is relatively affordable, battery-electric vehicles tend to cost less than their plug-in hybrid or combustion-engine counterparts.

In the future, the researchers want to expand this analysis to include a temporal dimension, so the framework also considers how changes in vehicle, fuel, and electricity prices affect emissions and costs over time. 

“While we found that the electricity mix is a big driver of the spatial variation in emissions savings of EVs, the electricity grid is decarbonizing everywhere. As that happens, emissions savings across space will become more homogenous for EVs, but the differences across one driver to another will remain,” Miotti says.

They could also use the framework to explore regions outside the United States or incorporate data on hybrid-electric vehicles that cannot be plugged in.

This work was funded, in part, by the MIT Martin Family Society of Fellows for Sustainability.

© Credit: iStock

Electric vehicles are quick, quiet, and typically offer awesome packaging and an easier maintenance schedule than combustion-powered cars. Where they struggle to keep up with their gas-powered competition is on the refueling side of things.

Charging infrastructure is nowhere near what it is for gas-powered cars, and when one does find a charger, it can take a long time to get a battery that’s flat back to full. Now, CATL says it’s found a solution, and it’ll charge a battery from 10 to 98 percent in just 6.5 minutes.

More: This New Battery Could Outlive You, Never Mind Your Car

According to The Wall Street Journal, the new Shenxing 3 battery hits that mark in roughly 6.5 minutes, beating the charging capability BYD revealed just last month, which took nine minutes to go from 10 to 97 percent, or seven minutes from 10 to 70. Bernstein analysts told the publication the new battery “effectively closes the gap with ICE vehicles.”

CATL says the new pack is capable of a 10C charging rate and can go from 10 to 80 percent in just 3 minutes and 44 seconds. Even more impressive, the company claims the battery can still charge from 20 to 98 percent in around nine minutes even when temperatures plunge to -22 degrees Fahrenheit (-30 Celsius).

Perhaps most impressive is that CATL says these charging speeds don’t destroy long-term battery life. Evidently, the Shenxing 3 still retains over 90 percent of its capacity after 1,000 full charging cycles.

CATL also introduced the new Qilin 3 battery, which it says can deliver up to 621 miles (1,000 km) of range while weighing just 1,378 pounds (625 kg). That makes it significantly lighter than comparable packs and, according to the company, improves efficiency, acceleration, braking, and handling. Oh, and wait, there’s more.

A new Qilin Condensed battery can deliver up to 932 miles (1,500 km) of range in a sedan or over 621 miles (1,000 km) in a full-size SUV. Obviously, that kind of range would be a giant benefit for the EV industry as it would reduce range anxiety and the need for additional charging infrastructure.

CATL says the Shenxing 3 and Qilin 3 batteries are intended for production vehicles rather than distant concepts, with the first applications likely arriving within the next year or so. The more ambitious Qilin Condensed battery appears further off, while CATL says its sodium-ion battery will enter mass production by the end of 2026.

Electric vehicles are quick, quiet, and typically offer awesome packaging and an easier maintenance schedule than combustion-powered cars. Where they struggle to keep up with their gas-powered competition is on the refueling side of things. Charging infrastructure is nowhere near what it is for gas-powered cars, and when one does find a charger, it can take a long time to get a battery that’s flat back to full. Now, CATL says it’s found a solution, and it’ll charge a battery from 10 to 98 percent in just 6.5 minutes.

According to The Wall Street Journal, the new Shenxing 3 battery can hit that mark in roughly 6.5 minutes, beating the approximately nine-minute charging capability BYD revealed just last month. Bernstein analysts told the publication the new battery “effectively closes the gap with ICE vehicles.”

More: This New Battery Could Outlive You, Never Mind Your Car

CATL says the new pack is capable of a 10C charging rate and can go from 10 to 80 percent in just 3 minutes and 44 seconds. Even more impressive, the company claims the battery can still charge from 20 to 98 percent in around nine minutes even when temperatures plunge to -22 degrees Fahrenheit (-30 Celsius). Perhaps most impressive is that CATL says these charging speeds don’t destroy long-term battery life. Evidently, the Shenxing 3 still retains over 90 percent of its capacity after 1,000 full charging cycles.

CATL also introduced the new Qilin 3 battery, which it says can deliver up to 621 miles (1,000 km) of range while weighing just 1,378 pounds (625 kg). That makes it significantly lighter than comparable packs and, according to the company, improves efficiency, acceleration, braking, and handling. Oh, and wait, there’s more.

A new Qilin Condensed battery can deliver up to 932 miles (1,500 km) of range in a sedan or over 621 miles (1,000 km) in a full-size SUV. Obviously, that kind of range would be a giant benefit for the EV industry as it would reduce range anxiety and the need for additional charging infrastructure.

CATL says the Shenxing 3 and Qilin 3 batteries are intended for production vehicles rather than distant concepts, with the first applications likely arriving within the next year or so. The more ambitious Qilin Condensed battery appears further off, while CATL says its sodium-ion battery will enter mass production by the end of 2026.

Just after unveiling its all-new electric C-Class, Mercedes-Benz confirmed a key piece of its future EV strategy. The next generation of its electric models will draw power from battery cells supplied by South Korea’s Samsung SDI.

The agreement, signed earlier this week, secures a steady flow of nickel, cobalt, and manganese (NMC) battery cells. Samsung claims these packs will deliver strong energy density, long service life, and the kind of sustained output and range figures premium EV buyers have come to expect, at least on paper.

Read: Mercedes’ Electric C-Class Is The BMW i3’s Neue Nightmare

Mercedes has yet to put a firm date on when these NMC batteries from Samsung will make their debut. Still, industry insiders point to models built on the upcoming Mercedes Modular Architecture (MMA) from 2028 onward. That would cover a wide spread of compact and mid-size SUVs, along with a handful of coupes that, for now, remain unnamed.

German Cars, Asian Batteries

The German brand already offers several of its EVs with NMC batteries, including the CLA 250+ and CLA 350 4Matic, sourced from China’s CATL. In addition, the all-electric Mercedes VLE uses a 115 kWh NMC battery pack, while the newly-revealed electric C-Class uses a 94.5 kWh NMC battery, promising a range of up to 472 miles (760 km).

“This partnership brings together the innovative DNA of both companies,” Samsung SDI said. “It is meaningful in that SAMSUNG SDI has secured a battery order aimed at strengthening its position in the global EV market.”

There are trade-offs between nickel, cobalt, and manganese (NMC) batteries and lithium iron phosphate (LFP) packs, the two chemistries currently dominating the EV space. NMC’s headline advantage is energy density, which means more range from a similarly sized battery, something premium brands tend to prioritize.

LFP, on the other hand, takes a more pragmatic approach. These packs are typically more durable over time and can be charged to 100 percent far more frequently without accelerating degradation. That makes them well suited to daily-use scenarios, even if they cannot quite match NMC’s outright range potential.

Some records stand for decades. Bob Beamon’s 8.9 m 1968 long jump, still unbroken 58 years later, is one. Others, like the 5 minutes it takes BYD’s Blade 2.0 battery to go from 10-70 percent, seem spectacular at the time, but here we are only weeks later and it’s already been smashed not once, but twice.

First it was Geely, whose Golden Brick battery can charge from 10-70 percent in 4 minutes 22 seconds. And now battery giant CATL has made even that look like it was hooked up to a household AC socket.

Related: Geely’s Golden Brick Battery Charges Faster Than BYD, But Good Luck Finding A Plug For It

CATL’s 3rd-gen Shenxing LFP battery stops the clock at 3 minutes 44 seconds. And that’s not even charging to 70 percent, but to 80 percent. Geely’s battery needs almost two minutes longer to reach the same point.

And that’s not the only crushing stat. If you’ve ever charged an EV, you’ll know that charge rates aren’t linear. It takes a while to reach peak charge speed and then the rate falls away again as the battery gets closer to full. But the CATL pack comes out all guns blazing, charging from 10-35 percent in just 1 minute.

And from 10-98 percent takes only 6 minutes and 27 seconds. That compares with 8 minutes 42 seconds for a 10-97 percent fill with Geely’s Golden Brick and 9 minutes for BYD’s Blade 2.0. Or to put it another way, the CATL goes from flat to full 13 seconds faster than it takes a Ford Mustang GTD to lap the Nurburgring.

Cold Weather? No Problem

These numbers are all achieved in optimal temperatures, of course, but CATL threw out another one to show that even in less than ideal condition charging is still really rapid. Drop the temperature to -30˚ C (-22˚F) and the 10-98 percent top-up still only takes 9 minutes.

Unveiling the new battery at its Tech Day Event, CATL claimed the pack’s 0.25 milliohms internal resistance is 50 percent lower than the industry average. It also features multi-point temperature monitoring for each cell and Self-Heating tech that involves using pulses of heat to improve low-temperature charging speeds.

Long Lifespan

Just as importantly, CATL claims that the battery health remains above 90 percent even after 1,000 ultra-fast charge cycles, countering skepticism from BMW engineers about the viability of the new generation of insanely fast-filling Chinese batteries.

BYD has already begun to expand its Flash Charging network to Europe, and CATL also claims it’s looking into bringing its own tech behind China’s borders together with SAIC-GM-Wuling. But don’t bank on it arriving in the US any time soon.

CATL, Ford

Advancements in battery innovation are transforming both mobility and energy systems alike, according to Kurt Kelty, vice president of battery, propulsion, and sustainability at General Motors (GM). At the MIT Energy Initiative (MITEI) Fall Colloquium, Kelty explored how GM is bringing next-generation battery technologies from lab to commercialization, driving American battery innovation forward. The colloquium is part of the ongoing MITEI Presents: Advancing the Energy Transition speaker series.

At GM, Kelty’s team is primarily focused on three things: first, improving affordability to get more electric vehicles (EVs) on the road. “How do you drive down the cost?” Kelty asked the audience. “It's the batteries. The batteries make up about 30 percent of the cost of the vehicle.” Second, his team strives to improve battery performance, including charging speed and energy density. Third, they are working on localizing the supply chain. “We've got to build up our resilience and our independence here in North America, so we're not relying on materials coming from China,” Kelty explained.

To aid their efforts, resources are being poured into the virtualization space, significantly cutting down on time dedicated to research and development. Now, Kelty’s team can do modeling up front using artificial intelligence, reducing what previously would have taken months to a couple of days.

“If you want to modify … the nickel content ever so slightly, we can very quickly model: ‘OK, how’s that going to affect the energy density? The safety? How’s that going to affect the charge capability?’” said Kelty. “We can look at that at the cell level, then the pack level, then the vehicle level.”

Kelty revealed that they have found a solution that addresses affordability, accessibility, and commercialization: lithium manganese-rich (LMR) batteries. Previously, the industry looked to reduce costs by lowering the amount of cobalt in batteries by adding greater amounts of nickel. These high-nickel batteries are in most cars on the road in the United States due to their high range. LMR batteries, though, take things a step further by reducing the amount of nickel and adding more manganese, which drives the cost of batteries down even further while maintaining range.

Lithium-iron-phosphate (LFP) batteries are the chemistry of choice in China, known for low cost, high cycle life, and high safety. With LMR batteries, the cost is comparable to LFP with a range that is closer to high-nickel. “That’s what’s really a breakthrough,” said Kelty.

LMR batteries are not new, but there have been challenges to adopting them, according to Kelty. “People knew about it, but they didn’t know how to commercialize it. They didn’t know how to make it work in an EV,” he explained. Now that GM has figured out commercialization, they will be the first to market these batteries in their EVs in 2028.

Kelty also expressed excitement over the use of vehicle-to-grid technologies in the future. Using a bidirectional charger with a two-way flow of energy, EVs could charge, but also send power from their batteries back to the electrical grid. This would allow customers to charge “their vehicles at night when the electricity prices are really low, and they can discharge it during the day when electricity rates are really high,” he said.

In addition to working in the transportation sector, GM is exploring ways to extend their battery expertise into applications in grid-scale energy storage. “It’s a big market right now, but it’s growing very quickly because of the data center growth,” said Kelty.

When looking to the future of battery manufacturing and EVs in the United States, Kelty remains optimistic: “we’ve got the technology here to make it happen. We’ve always had the innovation here. Now, we’re getting more and more of the manufacturing. We’re getting that all together. We’ve got just tremendous opportunity here that I’m hopeful we’re going to be able to take advantage of and really build a massive battery industry here.”

This speaker series highlights energy experts and leaders at the forefront of the scientific, technological, and policy solutions needed to transform our energy systems. Visit MITEI’s Events page for more information on this and additional events.

© Photo: Gretchen Ertl

Around 80 percent of global energy production today comes from the combustion of fossil fuels. Combustion, or the process of converting stored chemical energy into thermal energy through burning, is vital for a variety of common activities including electricity generation, transportation, and domestic uses like heating and cooking — but it also yields a host of environmental consequences, contributing to air pollution and greenhouse gas emissions.

Sili Deng, the Doherty Chair in Ocean Utilization and associate professor of mechanical engineering at MIT, is leading research to drive the transition from the heavy dependence on fossil fuels to renewable energy with storage.

“I was first introduced to flame synthesis in my junior year in college,” Deng says. “I realized you can actually burn things to make things, [and] that was really fascinating.”

Deng says she ultimately picked combustion as a focus of her work because she likes the intellectual challenge the concept offers. “In combustion you have chemistry, and you have fluid mechanics. Each subject is very rich in science. This also has very strong engineering implications and applications.”

Deng’s research group targets three areas: building up fundamental knowledge on combustion processes and emissions; developing alternative fuels and metal combustion to replace fossil fuels; and synthesizing flame-based materials for catalysis and energy storage, which can bring down the cost of manufacturing battery materials.

One focus of the team has been on low-cost, low-emission manufacturing of cathode materials for lithium-ion batteries. Lithium-ion batteries play an increasingly critical role in transportation electrification (e.g., batteries for electric vehicles) and grid energy storage for electricity that is generated from renewable energy sources like wind and solar. Deng’s team has developed a technology they call flame-assisted spray pyrolysis, or FASP, which can help reduce the high manufacturing costs associated with cathode materials.

FASP is based on flame synthesis, a technology that dates back nearly 3,000 years. In ancient China, this was the primary way black ink materials were made. “[People burned] vegetables or woods, such that afterwards they can collect the solidified smoke,” Deng explains. “For our battery applications, we can try to fit in the same formula, but of course with new tweaks.”

The team is also interested in developing alternative fuels, including looking at the use of metals like aluminum to power rockets. “We’re interested in utilizing aluminum as a fuel for civil applications,” Deng says, because aluminum is abundant in the earth, cheap, and it’s available globally. “What we are trying to do is to understand [aluminum combustion] and be able to tailor its ignition and propagation properties.”

Among other accolades, Deng is a 2025 recipient of the Hiroshi Tsuji Early Career Researcher Award from the Combustion Institute, an award that recognizes excellence in fundamental or applied combustion science research.

© Photo: John Freidah/MIT MechE

Before batteries lose power, fail suddenly, or burst into flames, they tend to produce faint sounds over time that provide a signature of the degradation processes going on within their structure. But until now, nobody had figured out how to interpret exactly what those sounds meant, and how to distinguish between ordinary background noise and significant signs of possible trouble.

Now, a team of researchers at MIT’s Department of Chemical Engineering have done a detailed analysis of the sounds emanating from lithium ion batteries, and has been able to correlate particular sound patterns with specific degradation processes taking place inside the cells. The new findings could provide the basis for relatively simple, totally passive and nondestructive devices that could continuously monitor the health of battery systems, for example in electric vehicles or grid-scale storage facilities, to provide ways of predicting useful operating lifetimes and forecasting failures before they occur.

The findings were reported Sept. 5 in the journal Joule, in a paper by MIT graduate students Yash Samantaray and Alexander Cohen, former MIT research scientist Daniel Cogswell PhD ’10, and Chevron Professor of Chemical Engineering and professor of mathematics Martin Z. Bazant.

“In this study, through some careful scientific work, our team has managed to decode the acoustic emissions,” Bazant says. “We were able to classify them as coming from gas bubbles that are generated by side reactions, or by fractures from the expansion and contraction of the active material, and to find signatures of those signals even in noisy data.”

Samantaray explains that, “I think the core of this work is to look at a way to investigate internal battery mechanisms while they’re still charging and discharging, and to do this nondestructively.” He adds, “Out there in the world now, there are a few methods that exist, but most are very expensive and not really conducive to batteries in their normal format.”

To carry out their analysis, the team coupled electrochemical testing with recording of the acoustic emissions, under real-world charging and discharging conditions, using detailed signal processing to correlate the electrical and acoustic data. By doing so, he says, “we were able to come up with a very cost-effective and efficient method of actually understanding gas generation and fracture of materials.”

Gas generation and fracturing are two primary mechanisms of degradation and failure in batteries, so being able to detect and distinguish those processes, just by monitoring the sounds produced by the batteries, could be a significant tool for those managing battery systems.

Previous approaches have simply monitored the sounds and recorded times when the overall sound level exceeded some threshold. But in this work, by simultaneously monitoring the voltage and current as well as the sound characteristics, Bazant says, “We know that [sound] emissions happen at a certain potential [voltage], and that helps us identify what the process might be that is causing that emission.”

After these tests, they would then take the batteries apart and study them under an electron microscope to detect fracturing of the materials.

In addition, they took a wavelet transform — essentially, a way of encoding the frequency and duration of each signal that is captured, providing distinct signatures that can then be more easily extracted from background noise. “No one had done that before,” Bazant says, “so that was another breakthrough.”

Acoustic emissions are widely used in engineering, he points out, for example to monitor structures such as bridges for signs of incipient failure. “It’s a great way to monitor a system,” he says, “because those emissions are happening whether you’re listening to them or not,” so by listening, you can learn something about internal processes that would otherwise be invisible.

With batteries, he says, “we often have a hard time interpreting the voltage and current information as precisely as we’d like, to know what’s happening inside a cell. And so this offers another window into the cell’s state of health, including its remaining useful life, and safety, too.” In a related paper with Oak Ridge National Laboratory researchers, the team has shown that acoustic emissions can provide an early warning of thermal runaway, a situation that can lead to fires if not caught. The new study suggests that these sounds can be used to detect gas generation prior to combustion, “like seeing the first tiny bubbles in a pot of heated water, long before it boils,” says Bazant.

The next step will be to take this new knowledge of how certain sounds relate to specific conditions, and develop a practical, inexpensive monitoring system based on this understanding. “Now, we know what to look for, and how to correlate that with lifetime and health and safety,” Bazant says.

One possible application of this new understanding, Samantaray says, is “as a lab tool for groups that are trying to develop new materials or test new environments, so they can actually determine gas generation or active material fracturing without having to open up the battery.”

Bazant adds that the system could also be useful for quality control in battery manufacturing. “The most expensive and rate-limiting process in battery production is often the formation cycling,” he says. This is the process where batteries are cycled through charging and discharging to break them in, and part of that process involves chemical reactions that release some gas. The new system would allow detection of these gas formation signatures, he says, “and by sensing them, it may be easier to isolate well-formed cells from poorly formed cells very early, even before the useful life of the battery, when it’s being made,” he says.

The work was supported by the Toyota Research Institute, the Center for Battery Sustainability, the National Science Foundation, and the Department of Defense, and made use of the facilities of MIT.nano.

© Photo: Alexander Cohen

A German startup believes it has the recipe for electric vehicle battery cells that are cheaper, more energy dense, and less problematic for the environment than current lithium-ion cells. But commercialization seems a long way off. Theion announced Thursday in a press release that it is close to completing a 15 million euro (approximately $16.2...

Chinese researchers claim to have developed a process to recover nearly all of the lithium from used electric vehicle batteries for recycling. The Independent (via InsideEVs) reports on study results first published in the German academic journal Angewandte Chemie claiming recovery of 99.99% of lithium from a used battery, as well as 97% of nickel...

Deployment of 5-minute battery swaps could support hundreds of commercial EVs Ample says it's a straightforward retrofit, switching to its own battery packs Solution is less demanding on the grid than fast-charging stations California-based startup Ample is looking to deploy its battery-swapping tech with fleets of electric delivery trucks in...

Chinese battery firm CATL and automaker Nio are preparing to launch what the two companies claim will be the world's largest electric vehicle battery swapping network. CATL and Nio announced a technical partnership last year that included battery swapping, but on Tuesday they confirmed plans to start coordinating efforts as they build out battery...

SK On will supply batteries to Nissan for U.S.-made electric vehicles, the two companies announced Wednesday in a press release. Under the agreement, SK On will supply nearly 100 gigawatt-hours of batteries to Nissan from 2028 to 2033. They'll go into EVs produced at the automaker's Canton, Mississippi, assembly plant starting in 2028. Nissan...

Researchers in Norway are looking at ways to make electric vehicle battery cells more resilient. As part of an EU-funded project involving a series of battery suppliers and researchers, the Norwegian University of Science and Technology (NTNU) said in a recent press release (via Tech Xplore) that its researchers have been looking at different ways...

Honda is looking to source batteries from Toyota for U.S.-market hybrids amid continuing uncertainty over the Trump Administration's tariffs, Nikkei Asia reported Monday. Starting this fiscal year, Honda is planning to buy enough batteries for approximately 400,000 vehicles, according to the report. Honda sold 308,000 hybrids in the U.S. in 2024...

Once hyped as a potential cornerstone for an expanded European battery industry, Swedish battery maker Northvolt on Wednesday announced that it was filing for bankruptcy in its home country. "Like many companies in the battery sector, Northvolt has experienced a series of compounding challenges in recent months that eroded its financial position...

The following commentary was written by Mel Mackinm, director of state policy at Ceres, a nonprofit that works with investors and companies to advance clean energy policy. See our commentary guidelines for more information.

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Look out across Michigan and you’ll see groundbreakings for major solar panel manufacturing sites, huge investments to build battery cells, and sparkling new facilities to ensure the state stays in the driver’s seat as the auto industry moves into the future.

It seems Michigan manufacturing is having a moment.

It’s little wonder why. Michigan has always had the legacy, the workforce, the supply chains, and the know-how to serve as the epicenter of an American manufacturing renaissance. That’s exactly what’s happened since Congress finalized the nation’s largest-ever clean energy investment in the summer of 2022.

Powered by incentives for companies to manufacture and deploy clean energy infrastructure and technology here in the U.S., the Inflation Reduction Act has unlocked more than $360 billion in private-sector investment in less than two years, according to research from Climate Power. Its impact has been felt in every corner of the country with hundreds of new projects taking shape to build innovative technologies, employ hundreds of thousands of workers, and power the economy – all while cutting costs and pollution. But no other state has seen as much activity as Michigan, the site of 58 new clean energy projects.

Michigan policymakers deserve some credit for moving quickly to take full advantage of this opportunity. In 2022, Gov. Gretchen Whitmer made clear in her MI Healthy Climate Plan that she wanted to make Michigan one of the best places in the world to build and deploy clean energy. Lawmakers since followed her lead with legislation that will move the state to 100% clean electricity by 2040 and ensure clean power infrastructure can be built both quickly and responsibly – a pair of laws that boasted ample support from Michigan companies that recognize confronting climate change is also an economic opportunity.

These policies were designed to fully harness the Inflation Reduction Act, making clear that the state is ready to support the growing number of businesses that supply or rely on innovative clean technology. In response, businesses that include classic Michigan manufacturers like GM, global brands like Corning, and upstarts like Lucid Motors have flooded the state with more than $21.5 billion in new clean energy innovation and manufacturing investment, creating some 20,100 new jobs.

With projects located from Detroit to Holland to Traverse City, so much of the state is already benefitting. That includes communities that have so far been left behind in the 21st century economy. About half of the state’s recent clean energy investment is located in rural or low-income areas, such as Norm Fasteners’ $77 million facility that will create 200 electric vehicle supply chain jobs in Bath Charter Township.

Now is not the time to slow down. We are now in the throes of the 2024 election, and we all know Michigan has been getting a lot of attention. No matter what happens in November, Michigan and the U.S. must continue investing in this revamped manufacturing base. Policymakers on both sides of the aisle have prioritized rebuilding American industry to provide good jobs and bolster U.S. leadership

Michigan’s clean energy manufacturing boom provides clear evidence that this shared goal is coming to fruition. Policymakers at both the federal and state levels, along with leaders in the private sector, must maintain this momentum and the strong policy environment that will allow the U.S. and its workforce to lead the global economy in the emerging industries of the future – with Michigan, as it so often has, standing strong as the foundation.

Commentary: Michigan is the epicenter of America’s clean energy manufacturing renaissance is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.