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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 parked 50+ Cybercabs outside its Texas Factory with some crash tested
Dozens of Tesla Cybercabs have been spotted at Giga Texas crash testing facility ahead of launch.
Drone footage captured by longtime Giga Texas observer Joe Tegtmeyer shows over 50 units of Tesla Cybercab at the Austin factory campus, including several units clustered by Tesla’s on-site crash testing facility.
The outbound lot at Gigafactory Texas sits just outside the factory exit and serves as the primary staging area where finished vehicles are held before being loaded onto transport carriers or dispatched for validation testing. On any given day, the lot holds a mix of Model Y and Cybertruck units alongside the growing Tesla Cybercab fleet, as can be seen in the drone footage captured by Joe Tegtmeyer.
Tesla Cybercab fleet spotted at Gigafactory Texas on April 13, 2026 [Credit: Joe Tegtmeyer)
Tesla Cybercab fleet spotted at Gigafactory Texas [Credit: Joe Tegtmeyer)
Tesla Cybercab crash test units spotted at Gigafactory Texas [Credit: Joe Tegtmeyer)
Tesla announced its Spring 2026 software update, and it’s the most feature-dense seasonal release the company has put out. The update covers twelve named changes spanning FSD, voice AI, safety lighting, dashcam storage, and pet display customization, among other things.
The centerpiece for owners with AI4 hardware is a redesigned Self-Driving app. The new interface lets owners subscribe to Full Self-Driving with a single tap and view ongoing FSD usage stats directly in the vehicle.
Grok gets its biggest in-car upgrade yet. The update adds a “Hey Grok” hands-free wake word along with location-based reminders, so a driver can now say “remind me to pick up groceries when I get home” without touching the screen. Grok first arrived in vehicles in July 2025, but each update has pushed it closer to genuine daily utility. Musk framed the broader vision clearly at Davos in January, saying Tesla is “really moving into a future that is based on autonomy.”
On safety, the update introduces enhanced blind spot warning lights that integrate directly with the cabin’s ambient lighting, building on the blind spot door warning that arrived in update 2026.8.
Dog Mode has been renamed Pet Mode and now lets owners choose a dog, cat, or hedgehog icon and add their pet’s name to the display.
Dashcam retention now extends up to 24 hours, up from the previous one-hour rolling loop, with a permanent save option for any clip. Weather maps now show rain and snow with better color differentiation and include the past hour of precipitation data along the route.
Tesla has now established a clear rhythm of two major OTA pushes per year. As with last year’s Spring update, that cycle started taking shape in 2025 with adaptive headlights and trunk customization. The 2025 Holiday Update then added Grok to the vehicle for the first time. This Spring follows that structure: the Holiday update introduces new architecture, and the Spring update broadens it across the fleet.
Two notable features still did not make it. IFTTT automations, which launched in China earlier this year, were held back from this North American release for unknown reasons, and Apple CarPlay remains absent, reportedly still delayed by iOS 26 and Apple Maps compatibility issues.
Below is the full list of feature updates released by Tesla.
— Tesla (@Tesla) April 13, 2026
News
Tesla launches new Model Y interior option
Produced at Gigafactory Shanghai, the update applies to all five-seat Premium Model Y configurations and started being seen on customer deliveries this week. The move marks the first major interior refresh for the compact crossover since its global debut.
Tesla has rolled out a striking new interior choice for its best-selling Model Y in China, replacing the long-familiar white cabin with a fresh option: Zen Grey.
Produced at Gigafactory Shanghai, the update applies to all five-seat Premium Model Y configurations and started being seen on customer deliveries this week. The move marks the first major interior refresh for the compact crossover since its global debut.
The Zen Grey interior swaps the classic black-and-white contrast for a softer, more unified palette. Seats, door panels, and center console trim now feature a warm light-grey tone that covers far more surface area than before.
Previously, black accents on the console, door handles, and lower dashboard are now color-matched in the same pebbled vegan leather, creating a brighter, less clinical cabin.
Tesla describes the material as durable and easy to maintain while delivering a noticeably more premium feel. Early photos and videos from Chinese owners show the new shade reflecting natural light beautifully, giving the spacious Model Y an even airier, more inviting atmosphere without sacrificing the minimalist design customers expect:
🚨 First look at Tesla’s new Zen Grey interior, which differs slightly in tone and in placement compared to the now discontinued White Interior https://t.co/rRRuEOrbm4 pic.twitter.com/p7uyNfO3xY
— TESLARATI (@Teslarati) April 13, 2026
The change is not an added-cost upgrade but a direct replacement for the discontinued white interior on Shanghai-built vehicles. Customers configuring a new Model Y in China, Hong Kong, or Macau now see Zen Grey as the default light-colored choice.
The update also flows to export markets supplied by Giga Shanghai, including Australia, New Zealand, South Korea, Japan, and the Philippines. Tesla has used its Chinese factory as an innovation hub before, and executives appear to be testing broader appeal with this subtler, warmer tone that avoids the high-maintenance reputation sometimes associated with bright white leather.
Beyond the interior, the refreshed Model Y from Shanghai includes minor exterior tweaks such as blacked-out badges on some trims and optional dark 20-inch wheels.
These changes arrive as Tesla faces stiff competition from domestic EV makers in its largest market. By refreshing the Model Y’s cabin without raising prices, the company is signaling continued commitment to value and constant improvement.
With over 1.2 million Model Y units already on Chinese roads, the Zen Grey launch gives existing owners a fresh talking point and new buyers another reason to choose Tesla. As deliveries ramp up this month, the updated interior is expected to become the dominant light-colored choice across the Asia-Pacific region.
Tesla has not yet confirmed whether the Zen Grey will reach Fremont, Austin, or Berlin-built Model Ys, but Shanghai’s track record suggests the option could spread quickly if customer feedback remains strong.
Tesla parked 50+ Cybercabs outside its Texas Factory with some crash tested
Tesla 2026 Spring Update drops 12 new features owners have been waiting for
