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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 Cybercab is set to launch in Austin, Texas, on September 3, as the company has officially started sending out invitations to a dedicated event it will hold in the city where its headquarters is located.
The Cybercab is Tesla’s dedicated ride-sharing vehicle: it features just two seats and has no steering wheel or pedals. It is aimed at fully autonomous passenger transport, and will operate in the Robotaxi fleet alongside the Tesla Model Y, which has been performing driverless rides for real-world passengers for more than a year.
Thank you so much @Tesla for inviting us to the Cybercab launch in Austin! 🤠 pic.twitter.com/F1rAR8zd5O
— TESLARATI (@Teslarati) August 22, 2026
The launch of the Cybercab marks the next chapter in Tesla’s autonomy story. The company has been developing autonomous transport for years with its Full Self-Driving (Supervised) platform, which is available in any vehicle the company has built with the proper hardware and software capabilities.
Its capabilities vary by hardware and software version, but Tesla says its latest hardware version, known as AI4, can deliver full autonomy. However, future vehicles will operate with even more robust hardware packages, as Tesla will develop AI4.5 and AI5 for even more capability in its vehicles.
Following a report from The Information that surfaced earlier this week, the writing was on the wall that Tesla was set to launch Cybercab in the near term. The report stated Tesla could launch Cybercab as soon as the end of August. Tesla came close and has booked it for September 3.
The big thing with this event being scheduled is not necessarily that Tesla is launching a new vehicle, but instead that it is launching a vehicle that has no steering wheel or pedals and will operate exclusively on a self-driving program that is evidently nearing full autonomy. If the event allows vehicles to take passengers on public roads and drop them off wherever they please within the City of Austin, it will be a drastic advancement in the company’s self-driving story.
People have ridden in Cybercab previously: Tesla had the “We, Robot” event in October 2024, which allowed people to experience fully autonomous rides in a closed circuit at Warner Bros. Studios in Burbank.
🚨 Ride in a Tesla Cybercab with us
— TESLARATI (@Teslarati) May 11, 2025
Additionally, Tesla launched employee rides in Cybercab in July.
It’s a drastic step forward for Tesla, whose CEO, Elon Musk, has promised for years that the company would release a fully autonomous vehicle and platform capable of allowing drivers to relinquish any responsibility behind the wheel.
Elon Musk put a number on where he thinks SpaceX’s Starship program is headed by 2030, replying on X a day after President Trump signed a memo pushing the country toward 1,000 space launches and reentries a year.
The exchange started when Aaron Burnett, co-founder of propulsion startup Mach 33, posted that “1,000 launches/reentries is the goal,” quoting White House science adviser Michael Kratsios on the newly signed National Space Transportation Policy. Burnett noted that the FAA’s own bull-case forecast reached only 385 annual launches by 2030, while his firm’s conservative model already put SpaceX alone near 940. Musk responded, “We’re aiming to reach 30+ Starship launches/day in 2030, which is ~10k annualized. Still tiny numbers compared to airplane flights!”
We’re aiming to reach 30+ Starship launches/day in 2030, which is ~10k annualized.
Still tiny numbers compared to airplane flights!
— Elon Musk (@elonmusk) August 21, 2026
That figure is specific to Starship, the rocket SpaceX is still developing for orbital and lunar missions, not the Falcon 9 fleet that carries most of the company’s current launch volume. Starship has flown twice this year, a slower pace than the four and five flights SpaceX managed in 2024 and 2025. Getting from two flights a year to 30 a day is the scale of jump the new federal policy is meant to clear regulatory room for.
Trump’s memo, signed Thursday, directs agencies to identify new launch and reentry sites on federal land, including a new reentry site within 90 days, and to speed up the permitting and environmental reviews that have long slowed cadence growth. It also sets a goal of returning American astronauts to the moon by 2028 and placing initial lunar base elements by 2030, tying the launch buildout directly to NASA’s Artemis program.
SpaceX has already been pushing the FAA toward higher numbers on its own. The agency approved up to 44 annual Starship launches from Kennedy Space Center in February, on top of a 2024 review that raised the cap at Starbase in Texas to 25 a year. Those approvals cover a fraction of the 10,000 annual flights Musk is now describing, which shows how far current permitting still sits from the administration’s stated target.
The near-term test of all this is more modest. SpaceX cleared a full-duration, six-engine static fire on its next Starship vehicle this week, the last major hardware checkpoint before Flight 14, which is targeting no earlier than August 28 and is expected to attempt the vehicle’s first full orbital mission. Musk said last week that a tower catch of the upper stage is still probably months away, a reminder that the immediate roadmap remains far more incremental than the daily launch numbers he just posted.
Tesla will resolve its massive recall of nearly three million vehicles in China with stickers and a software update.
On Friday, Chinese regulators filed recall plans against Tesla, Xiaomi, Leapmotor, Xpeng, Chery, Geely, Dongfeng, Arcfox, and FAW to resolve what is essentially a carbon-copy issue throughout each of the companies’ vehicle models: emergency door release latches are simply not visible enough.
Tesla door handle saga gets its latest chapter and a big change is coming
The companies will be required to add things that will make these latches, which will open the door in the event of an emergency, more visible. Of the 7 million vehicles impacted, Tesla accounts for 2,975,910 units. More than 1.9 million of those are Model Y vehicles, with the rest, just over 970,000, being Model 3s.
To resolve the issue, Tesla is going to add warning labels to the emergency latches free of charge, and then utilize an Over-the-Air update to add a post-crash window-lowering strategy, according to CNEVpost.
This massive effort to fix the all-electric Model Y and Model 3’s emergency latch system comes just months after several probes across various markets identified the trouble some had identifying this latch. Those who had gotten involved in car accidents that stripped the vehicle of its power were not aware that every Tesla has emergency door latches.
China’s State Administration for Market Regulation (SAMR) said that severe crashes that disable a vehicle’s low-voltage system could not only hinder occupants from getting out, but also make it more difficult for emergency response workers to gain entry.
SAMR is starting to tighten the regulations it has on door handles on vehicles. A new mandatory national standard will take effect for all models starting January 1, 2027, and will require all doors to be equipped with mechanical release mechanisms. This will effectively end purely electronic door handles. Models already on sale with type approval have been granted a two-year transition period, which will enable things to change until January 2029.
Tesla Cybercab launch gets official date in Austin with dedicated event
SpaceX and a new Trump order that could rewrite the next decade of launches
