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 has officially opened Robotaxi access to everyone and everyone, but there is one catch: you have to have an iPhone.
Tesla’s Robotaxi service in Austin and its ride-hailing service in the Bay Area were both officially launched to the public today, giving anyone using the iOS platform the ability to simply download the app and utilize it for a ride in either of those locations.
It has been in operation for several months: it launched in Austin in late June and in the Bay Area about a month later. In Austin, there is nobody in the driver’s seat unless the route takes you on the freeway.
In the Bay Area, there is someone in the driver’s seat at all times.
The platform was initially launched to those who were specifically invited to Austin to try it out.
Tesla confirms Robotaxi is heading to five new cities in the U.S.
Slowly, Tesla launched the platform to more people, hoping to expand the number of rides and get more valuable data on its performance in both regions to help local regulatory agencies relax some of the constraints that were placed on it.
Additionally, Tesla had its own in-house restrictions, like the presence of Safety Monitors in the vehicles. However, CEO Elon Musk has maintained that these monitors were present for safety reasons specifically, but revealed the plan was to remove them by the end of the year.
Now, Tesla is opening up Robotaxi to anyone who wants to try it, as many people reported today that they were able to access the app and immediately fetch a ride if they were in the area.
We also confirmed it ourselves, as it was shown that we could grab a ride in the Bay Area if we wanted to:
🚨 Tesla Robotaxi ride-hailing Service in Austin and the Bay Area has opened up for anyone on iOS
Go download the app and, if you’re in the area, hail a ride from Robotaxi pic.twitter.com/1CgzG0xk1J
— TESLARATI (@Teslarati) November 18, 2025
The launch of a more public Robotaxi network that allows anyone to access it seems to be a serious move of confidence by Tesla, as it is no longer confining the service to influencers who are handpicked by the company.
In the coming weeks, we expect Tesla to then rid these vehicles of the Safety Monitors as Musk predicted. If it can come through on that by the end of the year, the six-month period where Tesla went from launching Robotaxi to enabling driverless rides is incredibly impressive.
News
Tesla analyst sees Full Self-Driving adoption rates skyrocketing: here’s why
“You’ll see increased adoption as people are exposed to it. I’ve been behind the wheel of several of these and the different iterations of FSD, and it is getting better and better. It’s something when people experience it, they will be much more comfortable utilizing FSD and paying for it.”
Tesla analyst Stephen Gengaro of Stifel sees Full Self-Driving adoption rates skyrocketing, and he believes more and more people will commit to paying for the full suite or the subscription service after they try it.
Full Self-Driving is Tesla’s Level 2 advanced driver assistance suite (ADAS), and is one of the most robust on the market. Over time, the suite gets better as the company accumulates data from every mile driven by its fleet of vehicles, which has swelled to over five million cars sold.
The suite features a variety of advanced driving techniques that many others cannot do. It is not your typical Traffic-Aware Cruise Control (TACC) and Lane Keeping ADAS system. Instead, it can handle nearly every possible driving scenario out there.
It still requires the driver to pay attention and ultimately assume responsibility for the vehicle, but their hands are not required to be on the steering wheel.
It is overwhelmingly impressive, and as a personal user of the FSD suite on a daily basis, I have my complaints, but overall, there are very few things it does incorrectly.
Tesla Full Self-Driving (Supervised) v14.1.7 real-world drive and review
Gengaro, who increased his Tesla price target to $508 yesterday, said in an interview with CNBC that adoption rates of FSD will increase over the coming years as more people try it for themselves.
At first, it is tough to feel comfortable with your car literally driving you around. Then, it becomes second nature.
Gengaro said:
“You’ll see increased adoption as people are exposed to it. I’ve been behind the wheel of several of these and the different iterations of FSD, and it is getting better and better. It’s something when people experience it, they will be much more comfortable utilizing FSD and paying for it.”
Tesla Full Self-Driving take rates also have to increase as part of CEO Elon Musk’s recently approved compensation package, as one tranche requires ten million active subscriptions in order to win that portion of the package.
The company also said in the Q3 2025 Earnings Call in October that only 12 percent of the current ownership fleet are paid customers of Full Self-Driving, something the company wants to increase considerably moving forward.
News
Tesla scores major court win as judge rejects race bias class action
The ruling means the 2017 lawsuit cannot proceed as a class action because plaintiff attorneys were unable to secure testimony commitments from at least 200 workers.
Tesla scored a significant legal victory in California after a state judge reversed a class certification in a high-profile race harassment case involving 6,000 Black workers at its Fremont plant. The ruling means the 2017 lawsuit cannot proceed as a class action because plaintiff attorneys were unable to secure testimony commitments from at least 200 workers ahead of a 2026 trial, a threshold the judge viewed as necessary to reliably represent the full group.
No class action
In a late-Friday order, California Superior Court Judge Peter Borkon concluded that the suit could not remain a class action, stating he could not confidently apply the experiences of a much smaller group of testifying workers to thousands of potential class members. His ruling reverses a 2024 decision by a different judge who had certified the case under the belief that a trial of that size would be manageable, as noted in a Reuters report.
The lawsuit was originally filed by former assembly-line worker Marcus Vaughn, who alleged that Black employees at Tesla’s Fremont factory were exposed to various forms of racially hostile conduct, including slurs, graffiti, and instances of disturbing objects appearing in work areas. Tesla has previously said it does not tolerate harassment and has removed employees found responsible for misconduct. Neither Tesla nor the plaintiffs’ legal team immediately commented on the latest ruling.
Tesla’s legal challenges
While the decertification narrows the scope of this particular case, Tesla still faces additional litigation over similar allegations. A separate trial involving related claims brought by a California state civil rights agency is scheduled just two months after the now-vacated class trial date. The company is also contending with federal race discrimination claims filed by the U.S. Equal Employment Opportunity Commission, alongside several individual lawsuits it has already resolved.
For now, the reversal removes the large-scale exposure Tesla would have faced in a unified class trial, shifting the dispute back to individual claims rather than a single mass action. The case is Vaughn v. Tesla, filed in Alameda County Superior Court.
Tesla opens Robotaxi access to everyone — but there’s one catch
Tesla analyst sees Full Self-Driving adoption rates skyrocketing: here’s why
