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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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A Tesla upfitter has offered to take over Cybertruck lines from the company in a last-ditch effort to save the all-electric pickup from being completely canceled in the middle of 2027.
Unplugged Performance, the Hawthorne, California-based Tesla aftermarket specialist, has publicly offered to take over Cybertruck production from Tesla, funding the effort “through a consortium of investors.”
An open offer to Tesla: We fully support putting Cybercab first, and we’d be glad to take the Cybertruck line off your hands.
We’d fund it with a consortium of investors and run it at no cost to Tesla’s floor space, headcount, or focus. All of that goes to Cybercab. Cybercab gets first call on battery cells too. We’ll wait our turn.
Tesla gains incremental profit: a license fee, plus FSD and Robotaxi network revenues on every vehicle built.
We’d build the Cybertruck, a three-row CyberSUV, and an unmanned CyberCargo hauler. More autonomous miles, across every surface of this planet and beyond.
Worth a conversation?— UP (@UnpluggedTesla) November 10, 2026
The proposal comes as Tesla prioritizes its Cybercab Robotaxi program and prepares to wind down Cybertruck assembly at Gigafactory Texas around mid-2027.
Founded in 2013 by Ben Schaffer and located adjacent to Tesla’s Design Studio and SpaceX, Unplugged Performance has become a leading provider of premium upgrades for Tesla vehicles, including extensive Cybertruck packages under its UP INVINCIBLE line.
Through its UP.FIT division, the company has also developed purpose-built police and fleet versions of the Cybertruck, including deliveries to agencies such as the Las Vegas Metropolitan Police Department.
In an X post on Tuesday, Unplugged said:
“An open offer to Tesla: We fully support putting Cybercab first, and we’d be glad to take the Cybertruck line off your hands. We’d fund it with a consortium of investors and run it at no cost to Tesla’s floor space, headcount, or focus. All of that goes to Cybercab. Cybercab gets first call on battery cells too. We’ll wait our turn. Tesla gains incremental profit: a license fee, plus FSD and Robotaxi network revenues on every vehicle built. We’d build the Cybertruck, a three-row CyberSUV, and an unmanned CyberCargo hauler. More autonomous miles, across every surface of this planet and beyond. Worth a conversation?”
The arrangement would free Tesla resources and manufacturing capacity for Cybercab while allowing continued production of the stainless-steel pickup and expanded variants. Unplugged Performance indicated it would wait for battery cells after Cybercab needs are met and would generate ongoing revenue for Tesla through licensing and software/network services on the vehicles it produces.
Following strong initial interest, Unplugged Performance posted a follow-up inviting potential investors and strategic partners to email cyber@unpluggedperformance.com. The company clarified that the outreach is solely to gauge interest and does not constitute an offer to sell securities or acceptance of funds at this stage.
The proposal arrives shortly after Elon Musk indicated that Cybertruck production in Texas would be phased out by roughly the middle of 2027 to expand Cybercab output.
Whether Tesla engages with the offer remains to be seen, but the public overture highlights both the aftermarket specialist’s deep experience with the Cybertruck platform and the growing focus on autonomy within Tesla’s manufacturing plans.
Elon Musk said the Tesla Cybercab will perform “a majority of all passenger miles” where it is allowed to operate and that point is “obvious to anyone with eyes and a brain.”
Musk used the point to double down on the company’s decision to ax the cult-favorite Cybertruck, as its production space will be removed and transitioned into additional Cybercab lines. The move has catalyzed a polarizing conversation on whether its right or wrong.
Whatever side you are on — it’s happening.
Dodge ended the Viper.
Audi retired the R8.
Mitsubishi said goodbye to the Lancer Evo.
Ford bid farewell to the Bronco (at one point).
Chevrolet sunset the Camaro.Tesla is ending the Cybertruck. I’m pissed. I’m upset.
Fans of those five automakers mentioned did the same thing. It happens. It sucks. I don’t like it.
But I still love Tesla. I love my Model Y. I hoped to be in a Cybertruck in a little under two years.
I won’t be. But I still won’t put my family in anything else. Too safe. Too advanced. Too much better than everything else.
— TESLARATI (@Teslarati) November 10, 2026
Regardless, Musk seems to be getting to the point that he is done talking about the choice. At some point, you have to think that this was truly a difficult decision for him and the company as well, and this is not something he took lightly. In fact, he’s probably a little bit disappointed with it, too.
But the point remains that the Cybertruck is gone. Musk’s focus is purely on developing an autonomous platform that the world will utilize for transportation, and he’s telling you that anyone “with eyes and a brain” can see it:
@PalmerLuckey @carlhancock Cybercab will do a majority of all passenger miles in any jurisdiction where it is not prohibited by law.
Obvious to anyone with eyes and a brain.
— Elon Musk (@elonmusk) November 10, 2026
Tesla is betting that all of its passengers in the future will be okay with not owning their own personal cars and will be fine with ride-hailing for the rest of their lives. Every dinner, every errand, every trip to the airport and transportation thereafter, will all be operated by ride-sharing, and in Tesla’s perfect world, it will happen in a Cybercab.
As of now, Cybercab is only active in Austin, but it has been spotted all over the country with a driver behind the wheel in those prototypes. In Austin, the car has no steering wheel or pedals for people to control the vehicle.
The Cybertruck dilemma is one that has truly come across the entire Tesla community and while it seems to be a great idea to keep it because people love it, the business side of things is steering Musk and Tesla in another direction.
Tesla has slimmed its Cybertruck offerings to offer only its most expensive trim: the Cyberbeast.
After announcing that the Cybertruck would no longer be produced and the company would wind down manufacturing sometime in the middle of 2027, Tesla started to eliminate some of the configurations offered to customers.
Tesla has stopped taking orders for the Cybertruck Premium AWD.
The Cyberbeast is now the only trim you can order, and its price went up $7,500 to $109,990.
Estimated deliveries have also slipped to March–June 2027 as the Giga Texas line heads toward its mid-2027 wind-down. https://t.co/o28epA0ZQl
— TESLARATI (@Teslarati) November 10, 2026
Now, only one remains: the $109,990 Cyberbeast. This is truly what seems like Tesla’s last effort to deter any remaining orders from coming in: eliminate the cheap trims and leave only the high-dollar vehicle within the lineup of Cybertruck options.
Those who want to take advantage of this last-ditch opportunity to own Tesla’s symbolic pickup have to pay to play.
Tesla says the reason for the wind down is truly because of Cybercab and its importance to the future.
Despite cries for Tesla to continue production of the pickup, Musk says it is too difficult to ramp a high-volume line instead of ending the truck altogether. He also says Cybercab is what will take passengers around for the “majority of all miles in any jurisdiction where it is not prohibited by law.”
@PalmerLuckey @carlhancock Cybercab will do a majority of all passenger miles in any jurisdiction where it is not prohibited by law.
Obvious to anyone with eyes and a brain.
— Elon Musk (@elonmusk) November 10, 2026
Tesla is going all in on autonomy, and that’s never been a secret. But the commitment to a two-door, two-seat Cybercab truly limits people from having options for labor or hobbies. It also limits people from having their entire family in a single car.
Parents with even a single child will be required to take multiple vehicles if Cybercab is truly the only option Tesla plans to have.
Elon Musk keeps justifying Tesla Cybertruck’s cancelation, but it’s confusing
Tesla has stated the Robovan will also be in production eventually, but it still does not seem like the most ideal vehicle to own. It seems like it is geared more toward commercial uses, but Tesla might have something in the pipeline for families.
Tesla upfitter offers to keep Cybertruck alive
Elon Musk says Tesla Cybercab future is ‘obvious to anyone with eyes and a brain’
