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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News
Tesla’s new Holiday perk is timed perfectly to make FSD a household name
Tesla AI4 owners get FSD (Supervised) through Christmas, New Year’s Eve and well into the post-holiday travel season.
Tesla quietly rolled out a free Full Self-Driving (Supervised) trial for roughly 1.5 million HW4 owners in North America who never bought the package, and the timing could very well be genius.
As it turns out, the trial doesn’t end after 30 days. Instead, it expires January 8, 2026, meaning owners get FSD (Supervised) through Christmas, New Year’s Eve and well into the post-holiday travel season. This extended window positions the feature for maximum word-of-mouth exposure.
A clever holiday gift
Tesla watcher Sawyer Merritt first spotted the detail after multiple owners shared screenshots showing the trial expiring on January 8. He confirmed with affected users that none had active FSD subscriptions before the rollout. He also observed that Tesla never called the promotion a “30-day trial,” as the in-car message simply reads “You’re Getting FSD (Supervised) For the Holidays,” which technically runs until after the new year.
The roughly 40-day period covers peak family travel and gatherings, giving owners ample opportunity to showcase the latest FSD V14’s capabilities on highway trips, crowded parking lots and neighborhood drives. With relatives riding along, hands-off highway driving and automatic lane changes could become instant conversation starters.
Rave reviews for FSD V14 highlight demo potential
FSD has been receiving positive reviews from users as of late. Following the release of FSD v14.2.1, numerous owners praised the update for its smoothness and reliability. Tesla owner @LactoseLunatic called it a “huge leap forward from version 14.1.4,” praising extreme smoothness, snappy lane changes and assertive yet safe behavior that allows relaxed monitoring.
-->Another Tesla owner, @DevinOlsenn, drove 600 km without disengagements, noting his wife now defaults to FSD for daily use due to its refined feel. Sawyer Merritt also tested FSD V14.2.1 in snow on unplowed New Hampshire roads, and the system stayed extra cautious without hesitation. Longtime FSD tester Chuck Cook highlighted improved sign recognition in school zones, showing better dynamic awareness. These reports of fewer interventions and a more “sentient” drive could turn family passengers into advocates, fueling subscriptions come January.
Elon Musk
Elon Musk predicts AI and robotics could make work “optional” within 20 years
Speaking on entrepreneur Nikhil Kamath’s podcast, Musk predicted that machines will soon handle most forms of labor, leaving humans to work only if they choose to.
Elon Musk stated that rapid advances in artificial intelligence and robotics could make traditional work unnecessary within two decades.
Speaking on entrepreneur Nikhil Kamath’s podcast, Musk predicted that machines will soon handle most forms of labor, leaving humans to work only if they choose to.
Work as a “hobby”
During the discussion, Musk said the accelerating capability of AI systems and general-purpose robots will eventually cover all essential tasks, making human labor a choice rather than an economic requirement. “In less than 20 years, working will be optional. Working at all will be optional. Like a hobby,” Musk said.
When Kamath asked whether this future is driven by massive productivity growth, Musk agreed, noting that people will still be free to work if they enjoy the routine or the challenge. He compared future employment to home gardening, as it is something people can still do for personal satisfaction even if buying food from a store is far easier.
“Optional” work in the future
Elon Musk acknowledged the boldness of his claim and joked that people might look back in 20 years and say he was wrong. That being said, the CEO noted that such a scenario could even happen sooner than his prediction, at least if one were to consider the pace of the advancements in AI and robotics.
-->“Obviously people can play this back in 20 years and say, ‘Look, Elon made this ridiculous prediction and it’s not true,’ but I think it will turn out to be true, that in less than 20 years, maybe even as little as ten or 15 years, the advancements in AI and robotics will bring us to the point where working is optional,” Musk said.
Elon Musk’s comments echo his previous sentiments at Tesla’s 2025 Annual Shareholder Meeting, where he noted that Optimus could ultimately eliminate poverty. He also noted that robots like Optimus could eventually provide people worldwide with the best medical care.
Elon Musk
Elon Musk reiterates why Tesla will never make an electric motorcycle
Tesla CEO Elon Musk preemptively shut down speculations about a Tesla road bike once more.
Tesla CEO Elon Musk preemptively shut down speculations about a Tesla road bike once more, highlighting that the electric vehicle maker has no plans to enter the electric motorcycle market.
Musk posted his clarification in a post on X.
Musk’s reply to a fun AI video
X user @Moandbhr posted an AI video featuring the Tesla CEO on the social media platform, captioning it with “Mr. Elon Musk Just Revealed the Game-Changing Tesla Motorcycle.” The short clip depicted Musk approaching a sleek, single-wheeled vehicle, stepping onto it, and gliding off into the distance amid cheers. The fun video received a lot of traction on X, gaining 3.1 million views as of writing.
Musk replied to the post, stating that a Tesla motorcycle is not going to happen. “Never happening, as we can’t make motorcycles safe. For Community Notes, my near death experience was on a road bike. Dirt bikes are safe if you ride carefully, as you can’t be smashed by a truck,” Musk wrote in his reply.
Musk’s Past Comments on Two-Wheelers
Musk also detailed his reservations about motorcycles in a December 2019 X post while responding to questions about Tesla’s potential ATV. At the time, he responded positively to an electric ATV, though he also opposed the idea of a Tesla road-going motorcycle. Musk did state that electric dirt bikes might be cool, since they do not operate in areas where large vehicles like Class 8 trucks are present.
-->“Electric dirt bikes would be cool too. We won’t do road bikes, as too dangerous. I was hit by a truck & almost died on one when I was 17,” Musk wrote in his post.
Considering Musk’s comments about dirt bikes, however, perhaps Tesla would eventually offer a road bike as a recreational vehicle. Such a two-wheeler would be a good fit for the Cybertruck, as well as future products like the Robovan, which could be converted into an RV.
Tesla’s new Holiday perk is timed perfectly to make FSD a household name
Elon Musk predicts AI and robotics could make work “optional” within 20 years
