News
University of Michigan uses recycled Kevlar fiber to solve lithium-sulfur battery life cycle issues
The University of Michigan Chemical Sciences and Engineering team, led by Professor Nicholas Kotov, has developed a “new biologically inspired battery membrane” with recycled Kevlar fibers that could quintuple electric vehicle ranges and have a lifespan of 1,000 cycles.
The Ann Arbor, Michigan research facility is one of the best in the world, and Kotov, whose research focuses on the development of biomimetic nanocomposites, the self-assembly of nanoparticles, and chiral nanostructures, has worked to change the narrative on lithium-sulfur cells. “There are a number of reports claiming several hundred cycles for lithium-sulfur batteries, but it is achieved at the expense of other parameters—capacity, charging rate, resilience, and safety,” Kotov said in a press release from the University. “The challenge nowadays is to make a battery that increases the cycling rate from the former 10 cycles to hundreds of cycles and satisfies multiple other requirements including cost.”
Lithium-sulfur batteries can enable five times the capacity of standard lithium-ion cells, which are used in electric vehicles. However, as Professor Kotov mentioned in his quote, the lifespan is significantly decreased due to chemical reactions between molecules. The most common reason for reduced life cycles in lithium-sulfur batteries is dendrites, which are appendages that are designed to receive communications from other cells. These can pierce the membrane of cells, reducing the life span and thus the life cycle of a battery cell.
Another problem is polysulfides, or small molecules of lithium and sulfur, can form and flow to the lithium. They bond and cause blockages, reducing the effectiveness of the membrane. “The membrane is needed to allow lithium ions to flow from the lithium to the sulfur and back—and to block the lithium and sulfur particles, known as lithium polysulfides.”
However, Kevlar, the same material used in bulletproof vests, can stop dendrites from penetrating the membrane using dense aramid fibers found in the material. The cells that Kotov and his team developed use recycled Kevlar fibers. The Kevlar “can enable lithium-sulfur batteries to overcome their Achilles heel of cycle life,” caused by the two previously mentioned reactions between molecules.
An example of the Kevlar system is shown in the images below, as the typical Celgard membrane on the left allows lithium polysulfides to flow through. The Kevlar membrane (right) blocked the polysulfides from traveling through.
“Just half an hour on, the Celgard membrane (left) leaks lithium polysulfides. However, the U-M membrane (right) completely blocks the lithium polysulfides 96 hours later. Image credit: Ahmet Emre, Kotov Lab.” Credit: University of Michigan
“Achieving record levels for multiple parameters for multiple materials properties is what is needed now for car batteries,” Kotov stated. Kotov added that the design of the lithium-sulfur batteries is “nearly perfect” due to its capacity and efficiency reaching theoretical limits. It can also behave more resiliently than lithium-ion cells in warm and cold weather climates, which both have effects on range and efficiency. However, fast charging could reduce the number of lifespans, Kotov added.
Lithium-sulfur batteries could be a good alternative as sulfur is more readily available and abundant than cobalt, which is controversial due to its mining practices. However, automakers like Tesla are reducing cobalt in their batteries vying for other metals, like nickel, instead. Sulfur’s low lifespan and instability, as it changes in size by 78 percent during charging, reduced the possibility of automakers using it in the past, The Independent reported.
The research was funded by the National Science Foundation and the Department of Defense.
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Tesla stock (NASDAQ: TSLA) has landed an elusive “must own” status from Wall Street firm Melius, according to a new note released early this week.
Analyst Rob Wertheimer said Tesla will lead the charge in world-changing tech, given the company’s focus on self-driving, autonomy, and Robotaxi. In a note to investors, Wertheimer said “the world is about to change, dramatically,” because of the advent of self-driving cars.
He looks at the industry and sees many potential players, but the firm says there will only be one true winner:
“Our point is not that Tesla is at risk, it’s that everybody else is.”
The major argument is that autonomy is nearing a tipping point where years of chipping away at the software and data needed to develop a sound, safe, and effective form of autonomous driving technology turn into an avalanche of progress.
Wertheimer believes autonomy is a $7 trillion sector,” and in the coming years, investors will see “hundreds of billions in value shift to Tesla.”
A lot of the major growth has to do with the all-too-common “butts in seats” strategy, as Wertheimer believes that only a fraction of people in the United States have ridden in a self-driving car. In Tesla’s regard, only “tens of thousands” have tried Tesla’s latest Full Self-Driving (Supervised) version, which is v14.
Tesla Full Self-Driving v14.2 – Full Review, the Good and the Bad
When it reaches a widespread rollout and more people are able to experience Tesla Full Self-Driving v14, he believes “it will shock most people.”
Citing things like Tesla’s massive data pool from its vehicles, as well as its shift to end-to-end neural nets in 2021 and 2022, as well as the upcoming AI5 chip, which will be put into a handful of vehicles next year, but will reach a wider rollout in 2027, Melius believes many investors are not aware of the pace of advancement in self-driving.
Tesla’s lead in its self-driving efforts is expanding, Wertheimer says. The company is making strategic choices on everything from hardware to software, manufacturing, and overall vehicle design. He says Tesla has left legacy automakers struggling to keep pace as they still rely on outdated architectures and fragmented supplier systems.
Tesla shares are up over 6 percent at 10:40 a.m. on the East Coast, trading at around $416.
News
Tesla on track to break Volkswagen’s historic record in Norway: report
As per Elbil Statistik, Tesla reached 26,127 Norwegian sales so far this year, without counting 13 imported Cybertrucks.
Tesla is surging towards a historic milestone in Norway this month, putting the company on track to break Volkswagen’s long-standing annual sales record in the country.
With 3,732 units sold in November alone and more than 26,000 delivered year-to-date, Tesla is poised to become one of the most successful car brands in Norway’s modern automotive history.
Tesla closes in on Norway’s all-time sales record
Norway’s demand for Tesla vehicles has intensified as drivers attempt to beat the incoming VAT changes on electric cars. Once the VAT changes take effect, the best-selling Model Y could become 50,000 kroner more expensive, as noted in a CarUp report. This has likely caused a rise in sales for Tesla in the country as of late.
As per Elbil Statistik, Tesla reached 26,127 Norwegian sales so far this year, without counting 13 imported Cybertrucks. This places the brand just hundreds of units away from surpassing Volkswagen’s 2016 record of 26,572 annual registrations. With one month left in 2025, it seems all but certain that Tesla will overtake Volkswagen’s all-time record in Norway.
Tesla sees challenges in Sweden
While Norway is delivering historic results, Tesla’s Swedish performance has moved in the opposite direction. Registrations have dropped 68% this year, totaling just 6,147 vehicles so far. November has seen only 291 deliveries, highlighting challenges in the domestic market’s momentum.
Tesla Sweden is also still dealing with an increasing number of union-backed protests and blockades. Despite the pressure, however, Tesla Sweden has maintained its stance, IF Metall union chair Marie Nilsson to urge Elon Musk to reconsider his perception of organized labor. She also stated that Swedish unions are not like their American counterparts, as they are not as combative.
Tesla Full Self-Driving has officially landed in a new country today, its seventh overall after it launched in both Australia and New Zealand earlier this year.
On Sunday, Tesla owners in South Korea reported that the company’s Full Self-Driving (Supervised) had started arriving in their vehicles. Owners reported that it was v14.1.4, which is not the latest version available in other countries, but is one of the most recent releases Tesla has deployed to drivers:
From 6 to 7
Tesla Full Self-Driving has launched in South Korea; the 7th country to have FSD https://t.co/X6gm1SyoxV
— TESLARATI (@Teslarati) November 23, 2025
This marks the seventh country in which Tesla has enabled its Full Self-Driving suite, following the United States and Puerto Rico, Canada, China, Mexico, Australia, and New Zealand.
Tesla launched Full Self-Driving most recently in Australia and New Zealand about three months ago. The expansion is a major breakthrough for the company as it aims to launch Full Self-Driving on a global scale.
However, the company’s biggest challenge thus far has been getting European regulatory agencies to handle the red tape that has inhibited Tesla from launching its semi-autonomous driving suite on the continent. Recently, it admitted that it sees a pathway through Dutch regulatory bodies, which seem to be the most willing to work with Tesla to get FSD in Europe.
Tesla Full Self-Driving appears to be heading to Europe soon
The company said that it has driven over 1 million kilometers safely on European roads across 17 different countries in internal testing. But its path to success will be by “partnering with the Dutch approval authority RDW to gain exemption for the feature. This involves proving compliance with existing regulations (UN-R-171 DCAS) + filing an exemption (EU Article 39) for yet-to-be-regulated behaviors like Level 2 systems off-highway, system-initiated lane changes with hands-off the wheel, etc.”
Perhaps the expansion into Europe will be the biggest challenge for Tesla, but it could also yield major results and advantages for the company moving forward. Tesla said it hopes to have FSD available in Europe sometime early next year.
For now, the expansion in South Korea is the latest win for Tesla and its self-driving efforts. In the U.S., it now turns its focus toward fully autonomous operation, as it works with state agencies to launch Robotaxi outside of Texas, California, and most recently, Arizona.
Tesla stock lands elusive ‘must own’ status from Wall Street firm
Tesla on track to break Volkswagen’s historic record in Norway: report
