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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 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.
Elon Musk
Tesla launches 200mph Model S “Gold” Signature in invite-only purchase
Tesla’s final 350-unit Signature Edition closes the book on two cars that changed everything.
Tesla has announced a super limited Signature Edition run of 250 Model S Plaid and 100 Model X Plaid units as an invite only purchase in a bid to give its original flagship vehicles a proper send-off.
When the Model S first launched in 2012, the first 1,000 units sold were “Signature” editions that required a $40,000 deposit and cost nearly $100,000 each. Those early buyers were Tesla’s first real believers. This new Signature Edition deliberately echoes that moment, bookending a 14-year run with numbered collector hardware.
Both models are finished in an exclusive Garnet Red paint not available on any current Tesla production vehicle, with gold Tesla T badges up front, a gold Plaid badge and Signature badge at the rear, and a white Alcantara interior featuring gold Plaid seat badges, gold piping, Signature-marked door sills, and a numbered dash plate. The Model S adds carbon ceramic brakes with gold calipers. Every unit ships with Tesla’s Luxe Package, bundling Full Self-Driving (Supervised), four years of Premium Service, free lifetime Supercharging, and a Signature Edition key fob. Both are priced at $159,420, a roughly $35,000 premium over standard Plaid inventory.
The discontinuation is part of a broader strategic shift. At Tesla’s Q4 2025 earnings call, Musk described the decision as “slightly sad” but necessary, saying: “It’s time to basically bring the Model S and X programs to an end with an honorable discharge, because we’re really moving into a future that is based on autonomy.”
The Fremont factory floor that built these cars is being converted to manufacture Optimus humanoid robots, with a target of one million units annually.
Elon Musk
Tesla FSD in Europe vs. US: It’s not what you think
Tesla FSD is approved in the Netherlands, but the European version differs from what US drivers use.
On April 10, 2026, the Dutch vehicle authority RDW granted Tesla the first European type approval for Full Self-Driving Supervised, making the Netherlands the first country on the continent to authorize Tesla’s semi-autonomous system for customer use on public roads.
As Teslarati reported, the RDW approval followed 18 months of testing, more than 1.6 million kilometers driven on EU roads, 13,000 customer ride-alongs, and documentation covering over 400 compliance requirements. Tesla Europe had been running public demo drives through cities like Amsterdam and Eindhoven since early 2026, giving passengers their first experience of the system on European streets.
The European version of FSD is not the same software US drivers use. The RDW’s own statement is direct, noting that the software versions and functionalities in the US and Europe “are therefore not comparable one-to-one.” We’ve compile a table below that captures the most significant differences between US-based Tesla FSD vs. European Tesla FSD that’s based on what regulators and Tesla have publicly confirmed.
| Feature | FSD US | FSD Europe (Netherlands) |
| Regulatory framework | Self-certification, post-market oversight | Pre-market type approval required (UN R-171 + Article 39) |
| Hands requirement | Hands-off permitted on highway | Hands must be available to take over immediately |
| Auto turning from stop lights | Available — navigates intersections, turns, and traffic signals autonomously | Available in EU build — confirmed in Amsterdam demo footage handling unprotected turns and signalized intersections |
| Driving modes | Multiple profiles including a more aggressive “Mad Max” mode | EU build is more conservative by default and errs on the side of restraint when it cannot confirm the limit |
| Summon | Available — Smart Summon navigates parking lots to driver | Status unclear — not confirmed as part of the RDW-approved feature set; urban FSD approval targeted separately for 2027 |
| Driver monitoring | Camera-based eye tracking | Stricter continuous monitoring with more frequent intervention alerts |
| Software version | FSD v14.3 | EU-specific builds that must be separately validated by RDW |
| Geographic restriction | US, Canada, China, Mexico, Australia, NZ, South Korea | Netherlands only; EU-wide vote pending summer 2026 |
| Subscription price | $99/month | €99/month |
| Full urban FSD scope | Available | Partial — separate urban application planned for 2027 |
The approval comes as Tesla is under real pressure to grow FSD subscriptions globally. Musk’s 2025 CEO compensation package, approved by shareholders, includes a milestone requiring 10 million active FSD subscriptions as one condition for his stock awards to vest. Tesla hit one million subscriptions during its Q4 2025 earnings call, which is a meaningful start, but still a long way from the target. Opening Europe as a market for subscriptions, rather than just hardware sales, directly accelerates that number.
Tesla has said it anticipates EU-wide recognition of the Dutch approval during summer 2026, which would extend FSD access to Germany, France, and other major markets through a mutual recognition process without each country repeating the full 18-month review. That timeline is Tesla’s projection, not a confirmed regulatory outcome. As Musk acknowledged at Davos in January 2026, “We hope to get Supervised Full Self-Driving approval in Europe, hopefully next month.”
Tesla launches new Model Y interior option
Tesla launches 200mph Model S “Gold” Signature in invite-only purchase
