News
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 launched unsupervised Robotaxi service in San Antonio, Texas, on November 9, 2026, with the first rides beginning at 5 a.m. local time.
The company’s official Robotaxi account on X posted the announcement just after midnight, sharing a map that outlines a large operational zone covering much of the city. The geofence is roughly 274 to 275 square miles, making it Tesla’s largest day-one Robotaxi service area to date.
🚨 Tesla just announced that Robotaxi is available in San Antonio, TX
First rides at 5am local time! https://t.co/azck6NlD8H
— TESLARATI (@Teslarati) November 9, 2026
The zone centers on downtown, covers nearly everything inside Loop 410, and extends north to Loop 1604 between Interstate 10 and U.S. 281, with further reach west past State Highway 151, east beyond I-35, and south toward I-37. This area encompasses about one million residents and hundreds of thousands of jobs.
San Antonio International Airport lies inside the geofence, though Tesla is not currently offering airport pickups or drop-offs. This hopefully will happen soon, as ride-sharing to and from the airport can be expensive.
The launch makes San Antonio Tesla’s eighth unsupervised Robotaxi city and its fifth in Texas, joining Austin, Houston, Dallas, and Fort Worth. Florida markets in Miami, Orlando, and Tampa are also live.
🚨 Here’s every active geofence, by size (not including the Bay Area geofence):
• Austin: 435 sq mi (first ride Jun 22, 2025) · Cybercabs live, expanded today • San Antonio: ~275 sq mi (first ride Nov 9, 2026) • Houston: 254 sq mi (Apr 18, 2026) • Fort Worth: 143 sq mi (Nov 2, 2026) • Dallas: 81 sq mi (Apr 18, 2026) • Miami: 31 sq mi (Jul 3, 2026) • Orlando: 26 sq mi (Jul 21, 2026) • Tampa: 24 sq mi (Jul 21, 2026)
— TESLARATI (@Teslarati) November 9, 2026
Service uses modified Model Y vehicles operating without a safety driver in the vehicle, consistent with recent unsupervised expansions. Cybercab two-seaters remain limited primarily to Austin for now. It’s worth noting that Dept. of Transportation officials in Texas have already ok’d the Cybercab’s operation in Austin, and one official called it “a tangible example of how quickly our transportation system is evolving.”
San Antonio was previously listed among near-term targets in Tesla’s October 2026 Robotaxi safety materials, alongside Las Vegas, Phoenix, and Jacksonville. The rapid Texas rollout follows Fort Worth’s unsupervised debut on November 2 and builds on Austin’s original launch in June 2025.
The 274-square-mile debut remains substantially larger than Waymo’s local footprint and marks continued progress in Tesla’s unsupervised autonomy efforts after starting the year with no such rides. The company has stated ambitions for broader 24/7 operations by the end of 2026 as vehicle counts and software reliability improve.
Tesla has started to perform earthworks engineering on the roughly 3,000-acre site in Fort Bend County, Texas, advancing the massive $10 billion Project Crystal Sun plan to build a vertically integrated solar manufacturing complex.
Flyover drone footage from S.E. Robinson, Jr. released this morning shows the location under development. Tesla has crews on site performing large clearings, but you can also see equipment staging areas, the use of an existing homestead, and active leveling across a substantial portion of the property.
Tesla has started construction on Project Crystal Sun, its $10B vertically integrated solar factory near Houston, Texas.
The plant will make everything from silicon ingots and wafers to finished cells and panels, with operations targeted for Q1 2029.
@SERobinsonJr with a great flyover of the facility:
— TESLARATI (@Teslarati) November 9, 2026
Public filings first submitted in July under Texas’s Jobs, Energy, Technology and Innovation Act describe a plant that would manufacture the full solar chain: everything from silicon ingots, wafers, coated cells, and finished modules.
Tesla projects 9,712 permanent jobs by 2033, ramping from roughly 1,900 positions in the first year of operations, plus a peak of about 1,147 construction jobs. Construction is targeted for 2026–2028, with commercial production beginning in the first quarter of 2029. An accompanying economic analysis estimates the project could add roughly $107 billion to Texas GDP over several decades.
Local incentives have cleared major hurdles. Lamar Consolidated Independent School District unanimously approved school-tax limitations in September, and Fort Bend County commissioners approved a package of abatements and related agreements in late October that could extend equipment tax breaks for as long as 35 years.
Tesla had previously indicated it was evaluating a competing out-of-state location.
The effort fits broader statements by Musk that Tesla and SpaceX are each working toward 100 gigawatts of annual U.S. solar manufacturing capacity. If built as described, Project Crystal Sun would stand as one of the largest domestic attempts to create a fully integrated solar supply chain on American soil.
While Tesla has not issued a formal groundbreaking announcement, the visible site preparation and high-profile social media activity represent a concrete step forward for a project that has moved from confidential filings to active earthworks in a matter of months.
Elon Musk continues to shed more reasons that justify the cancelation of the Tesla Cybertruck, but some of the reasons for the sunset, as well as the process the company is choosing, do not make a lot of sense.
Musk announced last week on X that Tesla would wind down Cybertruck production in mid-2027, a decision that aims to prioritize Cybercab and its importance to the company’s future and passenger transportation as a whole.
But some of what Tesla and Musk are saying does not seem to make much sense. From the process the company is taking with orders to some of the reasoning for the cancelation, the whole situation seems strange.
With that being said: I totally see the merit in prioritizing Cybercab, but I also believe there is room for Cybertruck, a vehicle that has traditionally had low volumes, especially now at its current price point. If it were not for the cancelation, Cybertruck would sell very few units with the recent price adjustments.
Musk Talks Order Rate vs. Production Rate
The first thing that does not make a lot of sense here is the fact that this morning, Musk said that “The Cybertruck order rate far exceeds our production rate. We will try to make as any as possible before shutting down the line in about 8 months, but will have to return deposits for a lot of people.”
The Cybertruck order rate far exceeds our production rate. We will try to make as many as possible before shutting down the line in about 8 months, but will have to return deposits for a lot of people.
This is not a case of Cybertruck being unprofitable, as has been misreported by legacy media, but rather that the opportunity cost of the complexity of Cybertruck is vastly outweighed by the value of incremental Cybercab production.
— Elon Musk (@elonmusk) November 9, 2026
Then why is Tesla STILL accepting orders for the Cybertruck if it already cannot fulfill its order log by mid-2027?
There are so many people ordering Cybertruck that will not receive it. If Tesla already is having trouble seeing how it will build its current orders, why would it allow additional ones?
There are going to be a lot of people who are very upset next June or July, all because they placed an order for a truck that Tesla knew it would not have the time to build. At this point, it seems like a better idea from a customer service standpoint to simply stop accepting orders on a certain date, build those trucks, fulfill those orders, and then close production.
Continuing to accept orders at this point seems wildly strange. If anything, it feels like the $59k Cybertruck orderers will be the ones who get the short end of the stick here, but that’s speculation and just a hunch on my end.
If not Cybertruck, then what?
With only the Model 3 and Model Y available for consumers, meaning the general public, to buy, there is now no utility vehicle in the Tesla lineup, and that is definitely a disappointment.
Ford already washed its hands of the Lightning, which means the Rivian R1T will likely be the best-selling EV pickup on the market, dueling with the GMC Hummer Pickup, Chevy Silverado EV, and the GMC Sierra EV. There are several pickups that are set to hit the market soon, like the Slate EV Truck, and Ford’s new EV pickup, the Fathom.
Tesla could provide some some transparency on what it is planning to do with a future pickup or utility design. Musk said in the past that something much cooler than a minivan will be built. Cries for a full-size SUV have been heard by Tesla, but the company seems to adamant on prioritizing ridesharing vehicles instead of vehicles people want for work, climate, or hobbies.
Some clarity here, past the point of “Tesla is still going to build cars” would be nice. Even a simple, “Yes” response from all the people asking if Tesla will build something larger would be more than enough. We don’t need all the details now, but something would be nice.
Closing Thoughts
More than anything, it is important to note that I do believe Tesla is making a tough decision and one that, from a business standpoint, does make sense. However, I also believe that there is room for the Cybertruck in Tesla’s lineup.
One thing I think it’s worth mentioning is Tesla is not that much different from many companies. They do things that are better for the business that will surely upset consumers. The difference is very few companies have a following like Tesla, so when these things happen, they feel very personal.
Add in the fact that Cybertruck has truly become a symbol of Tesla, and people are even more upset about it.
It will all get figured out, but it’s still very confusing when we step back and take a look at the bigger picture.
Tesla Robotaxi enters its newest city, reaching San Antonio
Tesla begins groundworks on $10B ‘Project Crystal Sun’ in Texas
