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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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Tesla Robotaxi app update now tells riders if Cybercab is the better choice
Tesla’s Robotaxi app now shows ETAs, wait times and availability for Cybercab and Model Y.
Tesla has rolled out a new vehicle selection screen in its Robotaxi app, and it puts the numbers riders care about most in front of them before they book.
Version 26.11.0 of the app shows the estimated arrival time, the expected wait and current availability for each vehicle option on a single screen, according to a video shared by @gheeunit on X on November 7. Riders deciding between a Cybercab and a Model Y Robotaxi can now compare those figures side by side instead of picking a car first and learning how long it will take afterward.
Tesla first gave riders that choice on September 3, the day paid Cybercab rides began in Austin. The original version of the screen listed the Cybercab, which seats two, next to the Model Y, which seats four. A later build, 26.8.2, added a seating capacity indicator so groups knew which car would fit them. What it did not show was whether choosing the Cybercab meant standing on the curb a few extra minutes.
Newest version of @robotaxi app has a new vehicle selector UI for choosing between Cybercab and Model Y and shows you the fare for both simultaneously! https://t.co/7qoDQ0vACX — mantequilla 🧈 (@gheeunit) November 7, 2026
That question matters more now than it did two months ago. Tesla had 45 Cybercabs on the Texas DMV roster when rides started. By late October the state listed 573, alongside 631 Model Ys, and community trackers logged a record 1,576 Cybercab sightings across Austin on Halloween alone. With two large fleets sharing one service area, the closest car and the quickest pickup are not always the same vehicle.
Inline availability also changes what happens when demand spikes. If no Cybercab is free nearby, the rider sees that on the selection screen rather than after trying to book one.
For now the comparison is mostly an Austin feature. Riders in Dallas, Houston, Fort Worth and the Florida markets are still matched with Model Y vehicles, though Tesla said on its third quarter earnings call that Cybercab rides would launch in Dallas this month.
The update follows a steady run of smaller changes to the rider experience. Late last month Tesla brought a quiet mode that blacks out the cabin screen to Model Y Robotaxis after first testing it in the Cybercab, and it has stretched Austin service to run from 6 a.m. to 2 a.m.
The Cybercab side of that selection screen is about to get much busier. Elon Musk said this week that Tesla will wind down Cybertruck production at Gigafactory Texas around the middle of 2027 to make room for more Cybercab output, and Tesla has said it is aiming to get Cybercabs to customers by the end of this year.
Tesla has not published official release notes for version 26.11.0.
Tesla is ending Cybertruck production sometime in mid-2027, according to CEO Elon Musk.
Musk made the announcement on X last night, which came as a shock to many. He said that the Cybertruck will end production “to make room for increased Cybercab production” at Gigafactory Texas.
It is a huge blow to the fans of Tesla who have come to love the Cybertruck and identify with it as a symbol of their fandom. It has been the best-selling electric pickup, but it has had an underwhelming sales performance in terms of what was expected. This is mostly due to Tesla not meeting the prices it planned to offer the Cybertruck, as its unveiling and actual release were four years apart.
Tesla will be winding down production of the Cybertruck at Gigafactory Texas around the middle of next year to make room for increased Cybercab production
— Elon Musk (@elonmusk) November 6, 2026
Overall, the responses were mixed. Some fans understood the move toward Cybercab production, especially as Tesla is truly pushing the autonomous future through its Robotaxi platform. However, others did not understand it.
“Damn, how many Cybercabs do you guys need?” one response read. Another said it was “Sad but understandable.”Even analyst Gary Black had responded to the news, stating he hoped Tesla planned to replace it with a traditional pickup design.
It doesn’t seem like that will be the case.
Tesla is so hell-bent on delivering autonomy and eventually providing a driverless service that owning a car seems like an arbitrary idea, according to their thesis. Instead, Cybercabs will be available to pick you up and drop you off on demand, safely, without any human help.
As a result, Tesla has thinned its lineup considerably, and one can only ask where the vehicle lineup goes from here. Eventually, it seems like Cybercab could be the only vehicle that Tesla will sell.
Elon Musk
SpaceX’s next Starship flight set to make history on Friday the 13th
SpaceX is targeting Friday, November 13 for Starship Flight 15 and its first ship catch.
SpaceX is targeting Friday, November 13 for Starship Flight 15, the mission the company plans to use for its first attempt at catching the ship itself with the launch tower.
SpaceX Vice President of Launch Kiko Dontchev shared the date on stage at the UP.Summit on Thursday, according to Ars Technica’s Eric Berger, who was in attendance. It is the first launch target to come directly from a SpaceX executive. Until now, the public schedule had relied on FAA air traffic planning slides, which listed Flight 15 for no earlier than November 8 and later November 12. SpaceX has not posted an official mission page yet, and no launch time has been shared.
The date lands inside the window Elon Musk sketched out last month. Speaking at Giga Texas on October 10, Musk said the flight would “probably launch a little bit before Thanksgiving,” as Teslarati reported. On SpaceX’s third quarter earnings call ten days later, he confirmed that Flight 15 would try to catch both the Super Heavy booster and the ship, and put the odds of a successful ship catch at “more likely than not.” SpaceX also aired an animation of the maneuver during that webcast, showing the ship swinging vertical over Starbase before dropping into the tower’s chopsticks.
The hardware is ready. Booster 22 fired all 33 of its Raptor engines for a full duration static fire at Pad 2 on October 25. Ship 42 followed with a single engine burn simulating a deorbit maneuver on October 26 and a 60 second firing of all six engines the next day, according to NASASpaceflight. Ship 42 had already rehearsed the catch in September, when the Pad 2 arms lifted it into position and crews connected the quick disconnect arm while the vehicle hung from the tower.
The remaining hurdle is regulatory. The FAA’s Starship page does not yet list a Flight 15 license. SpaceX President Gwynne Shotwell said in October that, after “significant constructive engagement with the FAA,” she expects the license to cover a return to the launch site and a tower catch for both stages. Bringing the ship home means a reentry path that heads toward land, rather than ending over open ocean as every Starship flight so far has.
SpaceX has caught Super Heavy three times, on Flights 5, 7 and 8, but the ship comes back from orbital velocity and has never been caught. Flight 14 on September 28 was the first Starship to reach orbit, deploying 26 Starlink V3 satellites before splashing down despite an early engine shutdown that Musk blamed on engine computer software.
Musk has called a successful ship catch “the first time that there’s been full recovery of an orbital class rocket,” and he has already named the step after it: a Flight 16 where both the booster and the ship fly again. NASASpaceflight reports that Ship 43, the next vehicle in line, is set for static fire testing in December.
Tesla Robotaxi app update now tells riders if Cybercab is the better choice
Tesla is ending Cybertruck production
