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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 (NASDAQ: TSLA) reported its earnings for the third quarter of 2026, marking a reasonable performance on the various financial metrics. Tesla still plans to hold a call that will field investor questions at 5:30 p.m. ET, 4:30 p.m. CT.
Here’s where Earnings came in:
- Total Revenues: $28.046 reported vs. $28.34B expected
- Non-GAAP EPS: $0.48 reported vs. $0.45 expected
- Operating Margin: 2.6 % reported vs. 2.5% expected
- Operating Income: $718M reported vs. $721M expected
- Free Cash Flow: $1.531B reported vs. ~-$4.51B expected
Tesla $TSLA Earnings Results:
Revenues: $28.046B
Non-GAAP EPS: $0.48
Operating Margin: 2.6%
Operating Income: $718M
FCF: $1.531B— TESLARATI (@Teslarati) October 21, 2026
Major Takeaways
Full Self-Driving (Supervised)
“FSD (Supervised)⁴ attach rate continued to grow, reaching over 75% of new vehicle deliveries in North America – our most mature market – a nearly twenty percentage point sequential increase. We believe that FSD is driving demand in markets where it is available, and we continue to work with regulators to get it approved in other markets.”
Tesla Semi
“We began volume production of Tesla Semi, our Class 8 heavy-duty truck. The top variant can go 500 miles at full 82,000 lbs gross combination weight while achieving an efficiency of 1.7 kWh/mile. That efficiency allows the Tesla Semi to use a third of the energy used by a comparable diesel truck to haul the same payload. In a transportation market where energy is one of the largest components of total cost per mile, this will provide a meaningful advantage to Tesla Semi operators.”
SI Compute
“We plan to reach 400 MW of SI training compute by the end of the year, supporting the development of both vehicle and humanoid robot autonomy software. Additionally, we continued construction for the Austin Fab, where we plan to start commissioning equipment in 2027.”
Robotaxi
“We began deployment of Cybercab into our Robotaxi fleet in Austin. We reached nearly two million cumulative unsupervised miles for our Robotaxi service as of the end of the quarter. Operating hours in Austin are now 6am to midnight, and we expect to reduce wait times via increased fleet supply and improvement of Robotaxi orchestration algorithms. Grok is available in Cybercab with access to Grok Bot and Connectors, which allows users to manage their inbox, calendars, files, chats and tasks – all hands free via voice command – making Cybercab a mode of transport, a productivity space and, with our entertainment options, a second living room.”
Interested in ordering a Tesla? Use my referral code for three free months of Full Self-Driving (Supervised) here.
Tesla (NASDAQ: TSLA) reports its earnings for Q3 today. Here’s what to expect, as the company will reveal its balance sheet after the market closes on Wednesday.
Tesla already reported deliveries just after Q3 ended, and it demolished Wall Street consensus estimates of roughly 462,000 vehicles. Tesla delivered 486,532 cars in the third quarter, which was a big beat, but was down 2.1 percent from the same quarter last year. Energy storage deployments were 13.7 GWh, up year-over-year.
Tesla showrooms picked clean ahead of Q3 end as demand looks strong
For the quarter, analysts have already compiled their predictions for what Tesla will report this afternoon:
- Total Revenues: $28.34B
- Non-GAAP EPS: $0.43
- Operating Margin: 2.5%
- Operating Income: $721M
- Free Cash Flow: ~-$4.51B
Here are a few things we are looking forward to hearing about on the call:
Automotive Gross Margin and Overall Profitability
This was 16.3 percent in Q2, down from 19.2 percent in Q1, and was impacted by warranty charges and some fading regulatory credits. Consensus implies overall gross margin near 18 percent, but a miss here would potentially reinforce concerns about pricing pressure on its vehicles.
Pay attention to energy storage margins as well, especially since Tesla missed GWh expectations, although it was still a strong quarter.
Robotaxi/Cybercab, Unsupervised FSD, and Optimus Progress
The Say questions from retail investors usually focus on these types of projects, and this quarter is no different. Scaling the Cybercab fleet beyond Austin amid the open NHTSA safety review, timeline for Unsupervised FSD in customer cars, Robotaxi unit economics, and Optimus cost per unit plus when it could start generating revenue, are all things to be looking for.
Any concrete timelines or regulatory path details will likely move the stock more than the near-term numbers. SpaceX merger speculation, which was detailed during SpaceX’s earnings call last night, may also surface, although the key details were shared last night.
Elon Musk just confirmed the Tesla and SpaceX merger step everyone was waiting for
Say Investor Questions
- How does the Cybercab fleet scale past Austin, and what’s the regulatory path outside Texas given NHTSA’s open safety review?
- When can we anticipate FSD unsupervised in customer cars?
- When will the CyberCab be available for customer purchase/ownership?
- What’s the unit economics per paid robotaxi mile, and how does it compare to the thirty-cent target?
- Tesla has acknowledged that HW3 vehicles cannot support unsupervised FSD. When will owners know whether they can upgrade their hardware for free, and when will Tesla provide a clear plan?
The full Earnings Call will be streamed this evening after market close around 5 p.m. this evening.
SpaceX confirmed the date of Starship’s 15th launch window with some massive ambitions for the mission, as it will attempt to catch Ship for the first time.
CEO Elon Musk confirmed during SpaceX’s Earnings Call last night on October 20 that it would launch Starship for its 15th test flight in November, and there are some incredible things the company wants to try, making it perhaps the most groundbreaking launch in the program’s history.
SpaceX delivers blockbuster Q3 results as Super Intelligence segment booms
The most major development of the call was SpaceX’s intention to catch Ship alongside catching the Super Heavy Booster, something that has happened in the past. SpaceX showed an animation of the Ship catch, which will be done on the launch tower’s chopsticks:
SpaceX has released a new Starship tower catch animation for the upcoming Flight 15! https://t.co/kStn01Da8u
— Truthful🛰️ (@Truthful_ast) October 20, 2026
This monumental goal is to catch both the Ship and Booster in a dual-catch scenario, an incredible feat since SpaceX has never been able to reuse a Ship after launch. Musk said it would be “the first time that an orbital launch vehicle has been fully recovered,” and said it would be a “profound technology milestone.”
Musk said the odds of success on this first Ship catch attempt are “more likely than not,” but SpaceX is ultimately prepared for more tries moving forward. The SpaceX frontman said that, starting next year, Starship would have a “steady stream” of flights through the end of the year.
The cadence will accelerate in 2027, with Musk stating the company plans to target weekly flights in the first half of 2027 and twice-weekly by year-end.
The Flight 15 attempt follows that of Flight 14, which took off in late September and was Starship’s first orbital mission. It deployed 26 Starlink V3 satellites, accomplished a controlled ocean splashdown of both stages, and shed more light on potential challenges for the program moving forward.
As of now, the Starship program is firing on all cylinders.
Interested in ordering a Tesla? Use my referral code for three free months of Full Self-Driving (Supervised) here.
Tesla Q3 2026 Earnings results: in-line revenues, slight beat on EPS
Tesla reports Q3 Earnings today: here’s what to expect
