

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
Tesla says it denied Musk CEO replacement report before it was published
Tesla says it responded to the WSJ’s request for comment, denying that it was in search of a new CEO to replace Elon Musk.

Tesla said that it denied seeking a replacement for CEO Elon Musk before a report was published claiming the company was considering a new frontman.
Last night, The Wall Street Journal reported that Tesla’s Board of Directors was looking for Musk’s replacement after he had devoted too much time to his role within the government. The publication revised its headline to the report no fewer than five times, initially stating the company was still seeking a replacement.
By the time the headline revisions were complete, it had outlined that Tesla had looked for a replacement a month ago, but had stopped its search following Musk’s commitment to Tesla during the company’s earnings call last month.
Shortly after the report surfaced, Board of Directors chairwoman Robyn Denholm officially issued a statement on behalf of Tesla:
“Earlier today, there was a media report erroneously claiming that the Tesla Board had contacted recruitment firms to initiate a CEO search at the company. This is absolutely false (and this was communicated to the media before the report was published). The CEO of Tesla is Elon Musk and the Board is highly confident in his ability to continue executing on the exciting growth plan ahead. – Robyn Denholm.”
Tesla Board Chair slams Wall Street Journal over alleged CEO search report
Interestingly, Denholm’s statement indicates it had responded to a request for comment from the Wall Street Journal before the report was published. This is especially interesting because Tesla does not typically respond to media outreach, as it dissolved its media department several years ago.
Tesla typically makes its statements publicly on X.
Musk also responded to the report, indicating that the WSJ had committed an “extremely bad breach of ethics” by publishing a “deliberately false article” that did not include Tesla’s “unequivocal denial beforehand.”
News
Robotaxis are already making roads safer, Waymo report reveals
Waymo Driver is already reducing severe crashes and enhancing the safety of vulnerable road users.

Industry leaders such as Elon Musk have always maintained that autonomous robotaxis will make roads safer. A recent blog post from Waymo about the safety of its self-driving cars suggests that Musk’s sentiments are on point.
Way More Safety
Waymo Driver is already reducing severe crashes and enhancing the safety of vulnerable road users. As per a new research paper set for publication in the Traffic Injury Prevention Journal, Waymo Driver had outperformed human drivers in safety, particularly for vulnerable road users (VRUs).
Over 56.7 million miles, compared to human drivers, Waymo Driver achieved a 92% reduction in pedestrian injury crashes. It also saw 82% fewer crashes with injuries with cyclists and 82% fewer crashes with injuries with motorcyclists. Waymo Driver also slashed injury-involving intersection crashes by 96%, which are a leading cause of severe road harm for human drivers. Waymo Driver saw 85% fewer crashes with suspected serious or worse injuries as well.
What They Are Saying
Mauricio Peña, Waymo’s Chief Safety Officer, was optimistic about Waymo Driver’s results so far. “It’s exciting to see the real positive impact that Waymo is making on the streets of America as we continue to expand. This research reinforces the growing evidence that the Waymo Driver is playing a crucial role in reducing serious crashes and protecting all road users,” the Chief Safety Officer noted.
Jonathan Adkins, Chief Executive Officer at Governors Highway Safety Association, also noted that Waymo’s results are very encouraging. “It’s encouraging to see real-world data showing Waymo outperforming human drivers when it comes to safety. Fewer crashes and fewer injuries — especially for people walking and biking — is exactly the kind of progress we want to see from autonomous vehicles,” Adkins stated.
Elon Musk
Tesla hints at June 1 launch of Robotaxi platform in Austin
Tesla has hinted at a potential launch date for the Robotaxi service in Austin, Texas.

Tesla just dropped its biggest hint yet about the potential launch date of its Robotaxi ride-hailing platform in Austin, Texas, shedding more light on when to expect it to take off.
In preparation for the ride-hailing service to launch, Tesla has been in talks with the City of Austin for months. It has also spent recent months bolstering its Full Self-Driving suite, aiming for it to handle initially supervised rides with the use of teleoperators to keep things safe and dependable, at least early on.
The company has also said that it expects the Robotaxi service, which will drive passengers in Tesla Model Y vehicles to start, to launch in Austin in June. However, Tesla has not given an exact date.
Now, Tesla is hinting that Robotaxi could launch on June 1, based on a very vague X post it published on May 1:
Of course, this is extremely speculative. However, it’s the first time Tesla has made any suggestions about a potential launch date, so it’s worth taking it seriously.
While the automaker has often missed timelines in the past, most notably the launch of a “feature-complete” Full Self-Driving platform, this is the first time we’ve seen Tesla be so adamant and truly reiterate a target date.
Tesla has not shied away from this June date for the Robotaxi launch yet, something that is worth noting as we move closer to June. All signs point toward Tesla being able to come through on this timeline, and it could be one of its biggest accomplishments yet on the grand scheme of things. The Robotaxi rollout will be controlled and small to start, the company noted on its most recent Earnings Call.
CEO Elon Musk said:
“The team and I are laser-focused on bringing robotaxi to Austin in June. Unsupervised autonomy will first be solved for the Model Y in Austin.”
At first, it also seems as if the first Robotaxi rides will be available to a select group, as Musk said the ability to order one will not be available to the general public until later in the month. He also said the initial fleet will be between 10 and 20 vehicles:
“Yeah. We’re still debating the exact number to start off on day one, but it’s, like, I don’t know, maybe 10 or 20 vehicles on day one. And watch it carefully. They scale it up rapidly after that. So, we want to make sure that you’re paying very close attention the first time this happens. But, yeah, you will be able to — end of end of June or July, just go to Austin and order a Tesla for autonomous drive.”
While the June 1st date of the Robotaxi launch is extremely speculative, Tesla seems convinced that its vehicles could already handle this task. It would be something to see them come through on this date, especially on the first day of the month.
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