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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 Roadster: Three configs, one can fly, 0-60 in 0.8 seconds
Tesla’s Roadster comes in Performance, Thrust and Rocket versions, with a claimed 0-60 under 0.59 seconds.
Tesla finally showed the next generation Roadster on Thursday night, and the demo had more in common with a SpaceX test than a track lap. At an event outside Waco, Texas, near SpaceX’s McGregor site, the car used a mix of fans and cold gas thrusters to drive up a curved ramp until it was upside down, then flew off, flipped and landed on the pavement. “Well, it worked,” Elon Musk said. “Flying cars are real.”
The Roadster also hovered itself over a Cybercab, Cybertruck, Tesla Semi, Model Y and Model 3 while moving, and that Tesla showed it going 0 to 60 mph in one second. Musk said “this will be the actual car that’s on the roads” and that it “literally is just going to puff itself up” to perform the maneuvers whenever an owner wants. He called the result a collaboration between Tesla and SpaceX engineers that is “better than any James Bond car,” with Franz von Holzhausen and Lars Moravy on site.
Tesla published new mind-blowing stats for the car that replace the previous targets. The Performance version is road ready and seats two, with active aerodynamics and a multi-mode suction system, and Tesla lists 0 to 60 mph in under 1.6 seconds. The Thrust version is race ready, also seats two, and adds rear-mounted cold gas thrusters for a 0 to 60 time of under 0.9 seconds. The Rocket version is described as air ready, seats one, and uses perimeter-mounted thrusters for forward and upward acceleration plus lateral rotational movement.
| Configuration | Seats | 0 to 60 mph |
|---|---|---|
| Performance | 2 | under 1.6 s |
| Thrust | 2 | under 0.9 s |
| Rocket | 1 | under 0.59 s |
Tesla’s own description: “So…yes, it can fly.” It lists a 0 to 60 time of under 0.59 seconds for Rocket, a top speed of up to more than 230 mph, and range of more than 300 miles. Tesla has not yet given pricing in the information we have seen, but has reopened $50,000 reservations in the newly updated Tesla Roadster configurator. Production is planned for Giga Texas in 2027 or 2028, and Musk has said it would follow the demo by 12 to 18 months.
Every car on the road today is limited by one thing: tire grip
Roadster’s thruster system generates 4–5x the force the tires can.
More force on the same mass means significantly better acceleration – physics does the rest https://t.co/zdPRT2aKwZ
— Tesla (@Tesla) October 16, 2026
Tesla’s Roadster page adds more on how the car works. A multi-mode fan and ground sealing system pulls air from under the car, producing enough suction to hold it upside down even when stationary. Active wings, steer-by-wire with a yoke, and a Track Mode that lowers the car round out the driving setup. The cold gas thrusters use all-electric actuators for micro adjustments to stabilize the car in flight. Tesla says it cut weight with magnesium, titanium and carbon fiber, manual controls and a fixed seat position, and the exterior has hidden headlights, a full-length taillight and Ano White paint inspired by aerospace coatings. Inside are an Ultrawhite interior with gray microsuede, a center touchscreen and two smaller forward displays, and gold tinted glass modeled on spacesuit visors. Availability is tiered: Performance is by reservation, Thrust is a limited release, and Rocket is invite only. Tesla notes the car is not approved for public road use, and that Rocket is not available in all regions.
Tesla Roadster Highlights
- Aero and suction: a multi-mode fan and ground sealing system pulls air from under the car and can hold it upside down even when stationary. There are also active wings and a Track Mode that lowers the car.
- Controls and thrusters: steer-by-wire with a yoke. The cold gas thrusters use all-electric actuators for micro adjustments that stabilize the car in flight.
- Weight: magnesium, titanium and carbon fiber, manual controls and a fixed seat position.
- Design: hidden headlights, a full-length taillight, Ano White paint inspired by aerospace coatings, and gold tinted glass modeled on spacesuit visors.
- Interior: an Ultrawhite interior with gray microsuede, a center touchscreen and two smaller forward displays.
- Availability: Performance is by reservation, Thrust is a limited release, and Rocket is invite only.
- Road use: Tesla notes the car is not approved for public road use, and that Rocket isn’t available in all regions.
Musk has described the Roadster as “the best of the last of the human-driven cars,” and he has been open that it is a halo product. He said he is “not sure it moves the needle massively from a revenue standpoint,” and has warned that anyone whose top priority is safety should not buy it. Tesla reports third quarter earnings on October 21.
Roadster is a true pilot’s car: active aerodynamics, a multi-mode suction system & cold-gas thrusters
Exterior
– Concealed headlights, full-length taillight & flush-mounted surfaces for a minimalist, highly technical form– Super light wheels w/ thin spokes that reinforce structural strength when earthbound
– Ano White paint brings an aerospace-derived finish w/ UV & cryogenic protection, electrostatic dissipation & corrosion resistance
– Gold Glazed tinted glass mimicking the copper coating of spacesuit visors, w/ subtle titanium accents
— Tesla (@Tesla) October 16, 2026
Elon Musk
Amazon shuts out Elon Musk’s Grok Bot so he may just build his own rival store
Musk promises SpaceX will cover Grok Bot purchase errors, tells users to shop beyond Amazon.
Elon Musk said SpaceX will reimburse users if Grok Bot botches a purchase or leaks their card details. A few hours later he was telling users to take their shopping elsewhere after Amazon shut the agent out.
The first post was a reply to an X user who said Grok Bot booked him a flight after he sent a photo of his credit card. “This works well,” Musk wrote. “If Grok @Bot makes a mistake with a purchase or leaks your card (never happened yet), SpaceX will make you whole,” said Musk.
The second came after another user posted the error his Grok Bot hit on Amazon: “Continued access by an unauthorized AI agent violates Amazon’s Conditions of Use, to which our customers have agreed.” The user said his bots can no longer order from the site. Musk answered, “Just ask Grok @Bot to buy what you want someplace else and get a better deal. There are far more purchasing websites than just Amazon!” He later added, “Maybe we should start a competitor to Amazon,” a possible hint at an X shopping service.
Just ask Grok @Bot to buy what you want someplace else and get a better deal.
There are far more purchasing websites than just Amazon!
— Elon Musk (@elonmusk) October 15, 2026
The Amazon block did not start Thursday. A reply to Musk on October 10 said Amazon was blocking the bot, and Musk responded that Grok would find another way, then showed an order it placed on Lego’s website.
The latest reimbursement promise builds on late August when Musk told a Tesla investor weighing whether to give Grok Bot access to his bank accounts, “If Grok Bot messes up, we will make you whole,” as Teslarati covered when SpaceXAI added its Finance integration. That promise goes further than the company’s consumer terms, which make users responsible for what their agents do and generally cap liability at the greater of fees paid or $100. Neither Thursday post says those terms have changed, so for now it remains a statement on X rather than a published policy.
The two posts matter to Tesla owners because Grok Bot is no longer limited to a phone. Tesla brought it into its vehicles on September 22, and it is now enabled across every Cybercab and the rest of the Model Y Robotaxi fleet, as noted when Teslarati looked at why Grok Bot may be the Cybercab’s real advantage. A rider who asks for groceries or a coffee order is relying on retailers that let the agent in. Amazon has now said it will not, and Musk’s answer is to route around it.
Amazon has not commented publicly on the block in the posts Teslarati reviewed, and it is unclear whether Musk will follow through on a rival store.
So, how many of you do the vast majority of shopping on Amazon and hate that you do? Comment and let us know your thoughts!
Elon Musk
Elon Musk says Tesla’s Roadster demo could be a bang, quite literally
Musk says tonight’s Roadster demo will be a banger, maybe literally. The clues add up.
Elon Musk spent Wednesday and Thursday stacking teases on top of Tesla’s Roadster event, and the wording is getting harder to read as routine hype. Tesla streams the unveil tonight at 7:55 p.m. Central on X. Musk has called it “a candidate for greatest product demo of all time,” then added that “this demo will be a BANGER, probably metaphorically, though some chance literally.”
New Roadster is
beyond movies,
beyond imagination,
beyond human,
yet still made
by humans
on Earth— Elon Musk (@elonmusk) October 15, 2026
The “some chance literally” part is the line to watch. The Roadster has been tied to a SpaceX option package since 2018, and as we reported when the date was announced, the system is reportedly codenamed A71 and uses cold gas thrusters fed by a composite overwrapped pressure vessel, the same tank design SpaceX uses on Falcon 9. Musk has said a thruster equipped car could reach 60 mph in about 1.1 seconds. Cold gas thrusters firing at full output are loud, and reports ahead of the event say the car will be unmanned with spectators kept several hundred yards back. A literal bang could simply mean a demonstration that sounds like one, though it is also an admission that something could go wrong on stage.
Then there is “Timing is everything,” which Musk posted a day earlier. Stocktwits noted that 7:55 p.m. is 19:55 on a 24 hour clock, which echoes 1955, the year Marty McFly travels to in Back to the Future. Musk has made that connection before. In 2019 he replied to an animation of a flying DeLorean by saying the new Roadster “will actually do something like this.” Nothing from Tesla confirms the movie reference, but the stream time was chosen by someone, and Tesla has not been shy about this kind of wink.
Also, Tesla said it moved the event because it “can only be held outdoors,” and Musk then wrote that the demo was postponed “due to high winds,” as Teslarati covered at the time. A car running a standing start in front of a crowd shrugs off wind. A car that leaves the ground does not. The venue near SpaceX’s McGregor test site and the FAA airspace closures reported around the original date point the same way, though we also noted the delay could be a plain safety precaution. Musk has also described the new Roadster as “beyond movies, beyond imagination, beyond human, yet still made by humans on Earth.”
The only official figures remain the 2017 ones: 620 miles of range, a top speed above 250 mph, a 1.9 second 0 to 60 time, and prices of $200,000 for the base car and $250,000 for the Founders Series. Production is expected at Giga Texas in 2027 or 2028. Tesla has said the event will cover pricing, specifications and production targets, and its livestream preview has the full rundown. Tesla reports third quarter earnings on October 21, so whatever lands tonight will be fresh going into that call. We will have live coverage as soon as the stream starts.
Tesla Roadster: Three configs, one can fly, 0-60 in 0.8 seconds
Amazon shuts out Elon Musk’s Grok Bot so he may just build his own rival store
Elon Musk says Tesla’s Roadster demo could be a bang, quite literally
The Pentagon taps Elon Musk to design the battlefield of the future
SpaceX reveals how its 1 Million AI satellite network will work and prevent space collisions
