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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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Elon Musk’s Grokipedia surges to 5.6M articles, almost 79% of English Wikipedia
The explosive growth marks a major milestone for the AI-powered online encyclopedia, which was launched by Elon Musk’s xAI just months ago.
Elon Musk’s Grokipedia has grown to an impressive 5,615,201 articles as of today, closing in on 79% of the English Wikipedia’s current total of 7,119,376 articles.
The explosive growth marks a major milestone for the AI-powered online encyclopedia, which was launched by Elon Musk’s xAI just months ago. Needless to say, it would only be a matter of time before Grokipedia exceeds English Wikipedia in sheer volume.
Grokipedia’s rapid growth
xAI’s vision for Grokipedia emphasizes neutrality, while Grok’s reasoning capabilities allow for fast drafting and fact-checking. When Elon Musk announced the initiative in late September 2025, he noted that Grokipedia would be an improvement to Wikipedia because it would be designed to avoid bias.
At the time, Musk noted that Grokipedia “is a necessary step towards the xAI goal of understanding the Universe.”
Grokipedia was launched in late October, and while xAI was careful to list it only as Version 0.1 at the time, the online encyclopedia immediately earned praise. Wikipedia co-founder Larry Sanger highlighted the project’s innovative approach, noting how it leverages AI to fill knowledge gaps and enable rapid updates. Netizens also observed how Grokipedia tends to present articles in a more objective manner compared to Wikipedia, which is edited by humans.
Elon Musk’s ambitious plans
With 5,615,201 total articles, Grokipedia has now grown to almost 79% of English Wikipedia’s article base. This is incredibly quick, though Grokipedia remains text-only for now. xAI, for its part, has now updated the online encyclopedia’s iteration to v0.2.
Elon Musk has shared bold ideas for Grokipedia, including sending a record of the entire knowledge base to space as part of xAI’s mission to preserve and expand human understanding. At some point, Musk stated that Grokipedia will be renamed to Encyclopedia Galactica, and it will be sent to the cosmos.
“When Grokipedia is good enough (long way to go), we will change the name to Encyclopedia Galactica. It will be an open source distillation of all knowledge, including audio, images and video. Join xAI to help build the sci-fi version of the Library of Alexandria!” Musk wrote, adding in a later post that “Copies will be etched in stone and sent to the Moon, Mars and beyond. This time, it will not be lost.”
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Tesla Model 3 becomes Netherlands’ best-selling used EV in 2025
More than one in ten second-hand electric cars sold in the country last year was a Tesla Model 3.
The Tesla Model 3 became the most popular used electric car in the Netherlands in 2025, cementing its dominance well beyond the country’s new-car market.
After years at the top of Dutch EV sales charts, the Model 3 now leads the country’s second-hand EV market by a wide margin, as record used-car purchases pushed electric vehicles further into the mainstream.
Model 3 takes a commanding lead
The Netherlands recorded more than 2.1 million used car sales last year, the highest level on record. Of those, roughly 4.8%, or about 102,000 vehicles, were electric. Within that growing segment, the Tesla Model 3 stood far ahead of its competitors.
In 2025 alone, 11,338 used Model 3s changed hands, giving the car an 11.1% share of the country’s entire used EV market. That means more than one in ten second-hand electric cars sold in the country last year was a Tesla Model 3, Auto Week Netherlands reported. The scale of its lead is striking: the gap between the Model 3 and the second-place finisher, the Volkswagen ID3, is more than 6,700 vehicles.
Rivals trail as residual values shape rankings
The Volkswagen ID.3 ranked a distant second, with 4,595 used units sold and a 4.5% market share. Close behind was the Audi e-tron, which placed third with 4,236 registrations. As noted by Auto Week Netherlands, relatively low residual values likely boosted the e-tron’s appeal in the used market, despite its higher original price.
Other strong performers included the Kia Niro, the Tesla Model Y, and the Hyundai Kona, highlighting continued demand for compact and midsize electric vehicles with proven range and reliability. No other model, however, came close to matching the Model 3’s scale or market presence.
News
Tesla Model Y Standard Long Range RWD launches in Europe
The update was announced by Tesla Europe & Middle East in a post on its official social media account on X.
Tesla has expanded the Model Y lineup in Europe with the introduction of the Standard Long Range RWD variant, which offers an impressive 657 km of WLTP range.
The update was announced by Tesla Europe & Middle East in a post on its official social media account on X.
Model Y Standard Long Range RWD Details
Tesla Europe & Middle East highlighted some of the Model Y Standard Long Range RWD’s most notable specs, from its 657 km of WLTP range to its 2,118 liters of cargo volume. More importantly, Tesla also noted that the newly released variant only consumes 12.7 kWh per 100 km, making it the most efficient Model Y to date.
The Model Y Standard provides a lower entry point for consumers who wish to enter the Tesla ecosystem at the lowest possible price. While the Model 3 Standard is still more affordable, some consumers might prefer the Model Y Standard due to its larger size and crossover form factor. The fact that the Model Y Standard is equipped with Tesla’s AI4 computer also makes it ready for FSD’s eventual rollout to the region.
Top Gear’s Model Y Standard review
Top Gear‘s recent review of the Tesla Model Y Standard highlighted some of the vehicle’s most notable features, such as its impressive real-world range, stellar infotainment system, and spacious interior. As per the publication, the Model Y Standard still retains a lot of what makes Tesla’s vehicles well-rounded, even if it’s been equipped with a simplified interior.
Top Gear compared the Model Y Standard to its rivals in the same segment. “The introduction of the Standard trim brings the Model Y in line with the entry price of most of its closest competition. In fact, it’s actually cheaper than a Peugeot e-3008 and costs £5k less than an entry-level Audi Q4 e-tron. It also makes the Ford Mustang Mach-E look a little short with its higher entry price and worse range,” the publication wrote.
Elon Musk’s Grokipedia surges to 5.6M articles, almost 79% of English Wikipedia
Tesla Model 3 becomes Netherlands’ best-selling used EV in 2025
