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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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Elon Musk
Elon Musk spotlights the Starlink rescue that got through where no cell tower could
Elon Musk spotlighted how Starlink helped rescuers reach five people stranded in Kazakhstan’s snowy mountains.
Elon Musk put a spotlight on a mountain rescue in eastern Kazakhstan on Sunday, writing “Starlink saves lives” in response to a post describing how SpaceX’s satellite internet helped five stranded people reach emergency crews.
The post from DogeDesigner, which had been viewed more than 500,000 times by Sunday afternoon, said the group’s SUV broke down about 15 kilometers from the village of Kystau Kurchum in an area with no usable mobile network. Starlink carried their call for help and kept them in contact with rescuers, who used the connection to locate them.
The rescue itself took place in October. Local outlet YK.kz reported on October 22 that Kazakhstan’s Ministry of Emergency Situations responded to the breakdown in the Kurchum district of East Kazakhstan region and noted that the group stayed in touch through Starlink. Rescuers covered roughly 100 kilometers in a Trekol, a low pressure tire vehicle built for snow and marshland, then escorted the disabled SUV back to Kystau Kurchum. Nobody needed medical attention.
Starlink saves lives
— Elon Musk (@elonmusk) November 8, 2026
Conditions in the region were rough at the time. Kazakh broadcaster Channel 7 identified the five as hunters caught in a snow trap and said satellite communication allowed rescuers to pinpoint where they were. A spokesperson for the East Kazakhstan emergency department said a storm warning was in effect and urged residents not to leave populated areas unless necessary. The same weather stranded seven utility workers repairing power lines in the nearby Kuygan rural district, according to Tengrinews.
Kazakhstan has been one of Starlink’s more notable markets in Central Asia. Teslarati reported in 2024 that Starlink was serving 1,731 of the country’s 1,879 schools, with the country’s Education Minister saying it had set a new standard for internet service in schools.
Rescue stories like this one have followed Starlink for years, usually in places where ground networks fail or never existed in the first place. Then Florida CFO Jimmy Patronis called Starlink a “game changer” for search and rescue crews during Hurricane Milton, and SpaceX and T-Mobile switched on Starlink Direct to Cell in North Carolina to push emergency alerts to phones after Hurricane Helene.
The next target is dead zones for people who do not carry a dish at all. SpaceX is building out Starlink Mobile and earlier this week selected Qualcomm to supply core infrastructure for a planned terrestrial 5G network in the United States, which it intends to pair with its next generation satellite constellation.
Sunday’s post is at least the third time Musk has written “Starlink saves lives” on X this week, following identical posts on November 5 and November 7.
SpaceX plans to attempt what will be a defining moment in rocket reusability on Starship Flight 15.
As Elon Musk announced in a recent X post, SpaceX will attempt to catch both the Super Heavy Booster and the Starship upper stage during the upcoming orbital flight. If successful, it will mark the first time that all parts of an orbital rocket return to Earth intact, a breakthrough Musk has called essential to making life multiplanetary.
SpaceX will attempt to catch both the Super Heavy booster and Starship on the upcoming flight.
If both are successful, it will mark the first time that all parts of an orbital rocket return to Earth intact.
This is the critical breakthrough needed to make life multiplanetary.
— Elon Musk (@elonmusk) November 6, 2026
Previous flights have demonstrated the tower-catch technique with Super Heavy. SpaceX has successfully caught V1 boosters three times (on Flights 5, 7, and 8), with some even reflown. The Ship upper stage has never been caught.
Returning from orbital velocity after deploying payload makes it a significantly harder challenge due to higher energy, heat loads, and the need for precise belly-flop reentry, a flip maneuver, and a final landing burn to settle between the Mechazilla tower’s chopstick arms.
Flight 15, using Booster 22 and Ship 42 (both Block 3 vehicles), is targeted for no earlier than Friday, November 13, 2026, from Orbital Launch Pad 2 at Starbase, Texas. The 75-minute window opens at 4:45 p.m. CT, pending regulatory approval. After hot staging and separation, the booster is planned to return for a catch roughly 6 minutes and 35 seconds after liftoff.
The Ship will insert into a roughly 275 km orbit, deploy 26 advanced Starlink V3 satellites, complete about 14 orbits over more than 22 hours, and—if systems check out—perform a deorbit burn, reentry, flip, and landing burn for a tower catch at approximately T+22 hours 32 minutes.
SpaceX confirms Starship 15 launch window with massive ambitions
A simulation shown during SpaceX’s October earnings call depicted the Ship descending in a belly-flop attitude, flipping upright with a short engine burn, and being captured by the arms:
From simulation to reality
SpaceX is just ONE WEEK away from attempting its most ambitious Starship catch yet https://t.co/nHrxSX6DSz
— X Freeze (@XFreeze) November 6, 2026
Contingency splashdown zones exist in the Gulf of Mexico (booster) and Pacific (Ship) if a catch is not viable. SpaceX has stressed rigorous health checks before committing the Ship to a return-to-launch-site trajectory.
Musk has described the odds of success on this first dual-catch attempt as “more likely than not,” noting a steady stream of additional flights is already scheduled if needed. Full recovery would enable rapid inspection, refurbishment, and reflight—slashing costs and supporting the high launch cadence required for Starlink expansion, lunar missions, and eventual Mars settlement.
As Musk put it, this is “the critical breakthrough needed to make life multiplanetary.”
Tesla Cybercab is going to get some pretty substantial updates, including improvements to efficiency and a new color.
CEO Elon Musk said in a post on X on Saturday that Tesla would be working to refine the Cybercab even more, following the announcement during the week that the company would eliminate the Cybertruck lines within Giga Texas for more Cybercab manufacturing capacity.
“There are efficiency improvements coming that will allow for a 40kWh Cybercab pack,” Musk posted on X. “We will make this in liquid silver, so the colors are not too monotonous.”
There are efficiency improvements coming that will allow for a 40kWh Cybercab pack. We will make this in liquid silver, so the colors are not too monotonous.
The biggest thing most people fail to understand is that there are a very limited number of smart, dedicated people! They can only do so many things.
If we have to maintain a complex production line, supply chain and allocate engineering for Cybertruck, we can’t use those people or factory space and machinery for scaling Cybercab, which is the vehicle that will PROFOUNDLY transform the world of terrestrial transport!
— Elon Musk (@elonmusk) November 7, 2026
A new, more efficient model of the Cybercab will be engineered, which will only help Tesla’s profitability and margins, and it also boosts the argument for why the Cybertruck should be discontinued, at least from a business perspective.
The current Cybercab that operates in the Robotaxi platform in Austin, Texas, has a 48 kWh pack, and it sounds like Musk believes Tesla is on its way to introducing a version that has fewer cells but can manage the same workload thanks to engineering efficiencies.
Credit: Tesla
Musk also doubled down on the decision to prioritize Cybercab production over Cybertruck, which is a decision that has been extremely polarizing within the community, and many fans have made it abundantly clear that they are not particularly pleased with the plans.
“If we have to maintain a complex production line, supply chain, and allocate engineering for Cybertruck, we can’t use those people or factory space and machinery for scaling Cybercab, which is the vehicle that will PROFOUNDLY transform the world of terrestrial transport,” Musk said.
A good look at Tesla’s new Liquid Silver Cybercab, planned with a 40 kWh battery pack following new improvements
😍 https://t.co/IUYsUcCBMs
— TESLARATI (@Teslarati) November 8, 2026
Cybercab is obviously Tesla’s path forward in an automotive sense. It seems that Tesla is less concerned about catering to the passenger vehicle market and is more prone to focus on transforming passenger transportation in a way that prioritizes autonomy. However, this requires some sacrifice on Tesla’s end, and the Cybertruck is unfortunately a victim of this.
Cybercab holds an extremely crucial part of Tesla’s future. With the company already revolutionizing passenger transportation once, this is the next phase, and Cybercab is the path forward.
Elon Musk spotlights the Starlink rescue that got through where no cell tower could
SpaceX will perform Starship double catch attempt with Flight 15
