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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 makes latest move to remove Model S and Model X from its lineup
Tesla’s latest decisive step toward phasing out its flagship sedan and SUV was quietly removing the Model S and Model X from its U.S. referral program earlier this week.
Tesla has made its latest move that indicates the Model S and Model X are being removed from the company’s lineup, an action that was confirmed by the company earlier this quarter, that the two flagship vehicles would no longer be produced.
Tesla has ultimately started phasing out the Model S and Model X in several ways, as it recently indicated it had sold out of a paint color for the two vehicles.
Now, the company is making even more moves that show its plans for the two vehicles are being eliminated slowly but surely.
Tesla’s latest decisive step toward phasing out its flagship sedan and SUV was quietly removing the Model S and Model X from its U.S. referral program earlier this week.
The change eliminates the $1,000 referral discount previously available to new buyers of these vehicles. Existing Tesla owners purchasing a new Model S or Model X will now only receive a halved loyalty discount of $500, down from $1,000.
The updates extend beyond the two flagship vehicles. New Cybertruck buyers using a referral code on Premium AWD or Cyberbeast configurations will no longer get $1,000 off. Instead, both referrer and buyer receive three months of Full Self-Driving (Supervised).
The loyalty discount for Cybertruck purchases, excluding the new Dual Motor AWD trim level, has also been cut to $500.
NEWS: Tesla has removed the Model S and Model X from the referral program.
New owners also no longer get a $1,000 referral discount on a new Cybertruck Premium AWD or Cyberbeast. Instead, you now get 3 months of FSD (Supervised).
Additionally, Tesla has reduced the loyalty… pic.twitter.com/IgIY8Hi2WJ
— Sawyer Merritt (@SawyerMerritt) March 6, 2026
These adjustments apply only in the United States, and reflect Tesla’s broader strategy to optimize margins while boosting adoption of its autonomous driving software.
The timing is no coincidence. Tesla confirmed earlier this year that Model S and Model X production will end in the second quarter of 2026, roughly June, as the company reallocates factory capacity toward its Optimus humanoid robot and next-generation vehicles.
With annual sales of the low-volume flagships already declining (just 53,900 units in 2025), incentives are no longer needed to drive demand. Production is winding down, and Tesla expects strong remaining interest without subsidies.
Industry observers see this as the clearest sign yet of an “end-of-life” phase for the vehicles that once defined Tesla’s luxury segment. Community reactions on X range from nostalgia, “Rest in power S and X”, to frustration among long-time owners who feel perks are eroding just as the models approach discontinuation.
Some buyers are rushing orders to lock in final discounts before they vanish entirely.
Doug DeMuro names Tesla Model S the Most Important Car of the last 30 years
For Tesla, the move prioritizes efficiency: fewer discounts on outgoing models, a stronger push for FSD subscriptions, and a focus on high-margin Cybertruck trims amid surging orders.
Loyalists still have a narrow window to purchase a refreshed Plaid or Long Range model with remaining incentives, but the message is clear: Tesla’s lineup is evolving, and the era of the original flagships is drawing to a close.
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Tesla Australia confirms six-seat Model Y L launch in 2026
Compared with the standard five-seat Model Y, the Model Y L features a longer body and extended wheelbase to accommodate an additional row of seating.
Tesla has confirmed that the larger six-seat Model Y L will launch in Australia and New Zealand in 2026.
The confirmation was shared by techAU through a media release from Tesla Australia and New Zealand.
The Model Y L expands the Model Y lineup by offering additional seating capacity for customers seeking a larger electric SUV. Compared with the standard five-seat Model Y, the Model Y L features a longer body and extended wheelbase to accommodate an additional row of seating.
The Model Y L is already being produced at Tesla’s Gigafactory Shanghai for the Chinese market, though the vehicle will be manufactured in right-hand-drive configuration for markets such as Australia and New Zealand.
Tesla Australia and New Zealand confirmed the vehicle will feature seating for six passengers.
“As shown in pictures from its launch in China, Model Y L will have a new seating configuration providing room for 6 occupants,” Tesla Australia and New Zealand said in comments shared with techAU.
Instead of a traditional seven-seat arrangement, the Model Y L uses a 2-2-2 layout. The middle row features two individual seats, allowing easier access to the third row while providing additional space for passengers.
Tesla Australia and New Zealand also confirmed that the Model Y L will be covered by the company’s updated warranty structure beginning in 2026.
“As with all new Tesla Vehicles from the start of 2026, the Model Y L will come with a 5-year unlimited km vehicle warranty and 8 years for the battery,” the company said.
The updated policy increases Tesla’s vehicle warranty from the previous four-year or 80,000-kilometer coverage.
Battery and drive unit warranties remain unchanged depending on the variant. Rear-wheel-drive models carry an eight-year or 160,000-kilometer warranty, while Long Range and Performance variants are covered for eight years or 192,000 kilometers.
Tesla has not yet announced official pricing or range figures for the Model Y L in Australia.
A newly published Tesla patent could offer one of the clearest signals yet that the long-awaited next-generation Roadster is nearly ready for its public debut.
Patent No. US 20260061898 A1, published on March 5, 2026, describes a “vehicle seat system” built around a single continuous composite frame – a dramatic departure from the dozens of metal brackets, recliner mechanisms, and rivets that make up a traditional car seat. Tesla is calling it a monolithic structure, with the seat portion, backrest, headrest, and bolsters all thermoformed as one unified piece.
The approach mirrors Tesla’s broader manufacturing philosophy. The same company that pioneered massive aluminum castings to eliminate hundreds of body components is now applying that logic to the cabin. Fewer parts means fewer potential failure points, less weight, and a cleaner assembly process overall.
Tesla Roadster Seat Concept Image by TESLARATI
Tesla ramps hiring for Roadster as latest unveiling approaches
The timing of the filing is difficult to ignore. Elon Musk has publicly targeted April 1, 2026 as the date for an “unforgettable” Roadster design reveal, and two new Roadster trademarks were filed just last month. A patent describing a seat architecture suited for a hypercar, and one that Tesla has promised will hit 60 mph in under two seconds.
The Roadster, originally unveiled in 2017, has been one of Tesla’s most anticipated yet most delayed products. With a target price around $200,000 and engineering ambitions to match, it is being positioned as the ultimate showcase for what Tesla’s technology can do.
The patent was first flagged by @seti_park on X.
Tesla Roadster Monolithic Seat: Feature Highlights via US Patent 20260061898 A1
- Single Continuous Frame (Monolithic Construction). The core invention is a seat assembly built from one continuous frame that integrates the seat portion, backrest portion, and hinge into a single component — eliminating the need for separate structural parts and mechanical joints typical in conventional seats.
- Integrated Flexible Hinge. Rather than a traditional mechanical recliner, the hinge is built directly into the continuous frame and is designed to flex, and allowing the backrest to move relative to the seat portion. The hinge can be implemented as a fiber composite leaf spring or an assembly of rigid linkages.
- Thermoformed Anisotropic Composite Material. The continuous frame is manufactured via thermoforming from anisotropic composite materials, including fiberglass-nylon, fiberglass-polymer, nylon carbon composite, Kevlar-nylon, or Kevlar-polymer composites, enabling a molded-to-shape monolithic structure.
- Regionally Tuned Stiffness Zones. The frame is engineered with up to six distinct stiffness regions (R1–R6) across the seat, backrest, hinge, headrest, and bolsters. Each zone can have a different stiffness, allowing precise ergonomic and structural tuning without adding separate components.
- Linkage Assembly Hinge Mechanism. The hinge incorporates one or more linkage assemblies consisting of multiple interlocking links with gears, connected by rods. When driven by motors or actuators, these linkages act as a flexible member to control backrest movement along a precise, ergonomically optimized trajectory.
- Multi-Actuator Six-Degree-of-Freedom Positioning System. The seat uses four distinct actuator pairs, all controlled by a central controller. These actuators work in coordinated combinations to achieve fore/aft, height, cushion tilt, and backrest rotation adjustments simultaneously.
- ECU-Based Controller Architecture. An Electronic Control Unit (ECU) and programmable controller manage all seat actuators, receive user input via a user interface (touchscreen, buttons, or switches), and incorporate sensor feedback to confirm and maintain desired seat positions, essentially making this a software-driven seat system.
- Airbag-Integrated Bolster Deployment System. The backrest bolsters (216) are geometrically shaped and sized to guide airbag deployment along a specific, pre-configured trajectory. Left and right bolsters can have different shapes so that each guides its respective airbag along a distinct trajectory, improving occupant protection.
- Ventilation Holes Formed into the Backrest. The continuous frame includes one or more ventilation holes formed directly into the backrest portion, configured to either receive airflow into or deliver airflow from the seat frame — enabling passive or active thermal comfort without requiring separate ventilation components.
- Soft Trim Recess for Tool-Free Integration. The headrest and backrest portions together define a molded recess, specifically designed to receive and secure a soft trim component (foam, fabric, or cushioning) directly into the continuous frame, eliminating the need for separate attachment hardware and simplifying final assembly.
Tesla makes latest move to remove Model S and Model X from its lineup
Tesla Australia confirms six-seat Model Y L launch in 2026
