News
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
Elon Musk’s net worth is nearing $800 billion, and it’s no small part due to xAI
A newly confirmed $20 billion xAI funding round valued the business at $250 billion, adding an estimated $62 billion to Musk’s fortune.
Elon Musk moved within reach of an unprecedented $800 billion net worth after private investors sharply increased the valuation of xAI Holdings, his artificial intelligence and social media company.
A newly confirmed $20 billion funding round valued the business at $250 billion, adding an estimated $62 billion to Musk’s fortune and widening his lead as the world’s wealthiest individual.
xAI’s valuation jump
Forbes confirmed that xAI Holdings was valued at $250 billion following its $20 billion funding round. That’s more than double the $113 billion valuation Musk cited when he merged his AI startup xAI with social media platform X last year. Musk owned roughly 49% of the combined company, which Forbes estimated was worth about $122 billion after the deal closed.
xAI’s recent valuation increase pushed Musk’s total net worth to approximately $780 billion, as per Forbes’ Real-Time Billionaires List. The jump represented one of the single largest wealth gains ever recorded in a private funding round.
Interestingly enough, xAI’s funding round also boosted the AI startup’s other billionaire investors. Saudi investor Prince Alwaleed Bin Talal Alsaud held an estimated 1.6% stake in xAI worth about $4 billion, so the recent funding round boosted his net worth to $19.4 billion. Twitter co-founder Jack Dorsey and Oracle co-founder Larry Ellison each owned roughly 0.8% stakes that are now valued at about $2.1 billion, increasing their net worths to $6 billion and $241 billion, respectively.
The backbone of Musk’s net worth
Despite xAI’s rapid rise, Musk’s net worth is still primarily anchored by SpaceX and Tesla. SpaceX represents Musk’s single most valuable asset, with his 42% stake in the private space company estimated at roughly $336 billion.
Tesla ranks second among Musk’s holdings, as he owns about 12% of the EV maker’s common stock, which is worth approximately $307 billion.
Over the past year, Musk crossed a series of historic milestones, becoming the first person ever worth $500 billion, $600 billion, and $700 billion. He also widened his lead over the world’s second-richest individual, Larry Page, by more than $500 billion.
News
Tesla Cybercab sighting confirms one highly requested feature
The feature will likely allow the Cybercab to continue operating even in conditions when its cameras could be covered with dust, mud, or road grime.
A recent sighting of Tesla’s Cybercab prototype in Chicago appears to confirm a long-requested feature for the autonomous two-seater.
The feature will likely allow the Cybercab to continue operating even in conditions when its cameras could be covered with dust, mud, or road grime.
The Cybercab’s camera washer
The Cybercab prototype in question was sighted in Chicago, and its image was shared widely on social media. While the autonomous two-seater itself was visibly dirty, its rear camera area stood out as noticeably cleaner than the rest of the car. Traces of water were also visible on the trunk. This suggested that the Cybercab is equipped with a rear camera washer.
As noted by Model Y owner and industry watcher Sawyer Merritt, a rear camera washer is a feature many Tesla owners have requested for years, particularly in snowy or wet regions where camera obstruction can affect visibility and the performance of systems like Full Self-Driving (FSD).
While only the rear camera washer was clearly visible, the sighting raises the possibility that Tesla may equip the Cybercab’s other external cameras with similar cleaning systems. Given the vehicle’s fully autonomous design, redundant visibility safeguards would be a logical inclusion.
The Cybercab in Tesla’s autonomous world
The Cybercab is Tesla’s first purpose-built autonomous ride-hailing vehicle, and it is expected to enter production later this year. The vehicle was unveiled in October 2024 at the “We, Robot” event in Los Angeles, and it is expected to be a major growth driver for Tesla as it continues its transition toward an AI- and robotics-focused company. The Cybercab will not include a steering wheel or pedals and is intended to carry one or two passengers per trip, a decision Tesla says reflects real-world ride-hailing usage data.
The Cybercab is also expected to feature in-vehicle entertainment through its center touchscreen, wireless charging, and other rider-focused amenities. Musk has also hinted that the vehicle includes far more innovation than is immediately apparent, stating on X that “there is so much to this car that is not obvious on the surface.”
News
Tesla seen as early winner as Canada reopens door to China-made EVs
Tesla had already prepared for Chinese exports to Canada in 2023 by equipping its Shanghai Gigafactory to produce a Canada-specific version of the Model Y.
Tesla seems poised to be an early beneficiary of Canada’s decision to reopen imports of Chinese-made electric vehicles, following the removal of a 100% tariff that halted shipments last year.
Thanks to Giga Shanghai’s capability to produce Canadian-spec vehicles, it might only be a matter of time before Tesla is able to export vehicles to Canada from China once more.
Under the new U.S.–Canada trade agreement, Canada will allow up to 49,000 vehicles per year to be imported from China at a 6.1% tariff, with the quota potentially rising to 70,000 units within five years, according to Prime Minister Mark Carney.
Half of the initial quota is reserved for vehicles priced under CAD 35,000, a threshold above current Tesla models, though the electric vehicle maker could still benefit from the rule change, as noted in a Reuters report.
Tesla had already prepared for Chinese exports to Canada in 2023 by equipping its Shanghai Gigafactory to produce a Canada-specific version of the Model Y. That year, Tesla began shipping vehicles from Shanghai to Canada, contributing to a sharp 460% year-over-year increase in China-built vehicle imports through Vancouver.
When Ottawa imposed a 100% tariff in 2024, however, Tesla halted those shipments and shifted Canadian supply to its U.S. and Berlin factories. With tariffs now reduced, Tesla could quickly resume China-to-Canada exports.
Beyond manufacturing flexibility, Tesla could also benefit from its established retail presence in Canada. The automaker operates 39 stores across Canada, while Chinese brands like BYD and Nio have yet to enter the Canadian market directly. Tesla’s relatively small lineup, which is comprised of four core models plus the Cybertruck, allows it to move faster on marketing and logistics than competitors with broader portfolios.
Elon Musk’s net worth is nearing $800 billion, and it’s no small part due to xAI
Tesla Cybercab sighting confirms one highly requested feature
