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.
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The research was funded by the National Science Foundation and the Department of Defense.
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Elon Musk shed two new bits of detail on Starship following its 13th test launch, which was an overwhelming success.
SpaceX launched Starship for the 13th time last Friday after two delays: one on Monday when several Raptor engines did not ignite, and another on Thursday due to unfavorable weather conditions in Starbase, Texas.
The launch was overwhelmingly successful. SpaceX was able to complete a necessary test of the heat shield tiles by increasing the acceleration of Starship from launch throughout the flight; 20 Starlink v3 satellites were released with no issue; the Super Heavy Booster landed safely in the Gulf of America, Ship successfully reignited engines while in space; and it also splashed down without incident in the Indian Ocean.
SpaceX Starship just nailed something it’s never done before
Nevertheless, more details are coming out about Starship, and Musk is doing the talking.
Starship Will Be Retrieved in the Ocean
Musk revealed on Tuesday night that Starship would be recovered by a ship in the Indian Ocean. SpaceX routinely tries to recover Starship after splashdown in an effort to find out more about the flight by examining the spacecraft afterward.
We’re sending a ship out to recover Starship https://t.co/fUqUZTITO9
— Elon Musk (@elonmusk) July 28, 2026
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This helps engineers find out more about why things might have happened, allows them to examine any potential damage or anomalies that might have occurred, and increases the chances of an even more successful flight next time thanks to the additional information recovered.
Ship Could Have Been Caught by Tower Arms, Musk claims
Musk has already indicated that SpaceX will plan to attempt a catch of Starship with the 14th test flight. While this would be a major accomplishment, it would be an expected next step, considering the fact that the Super Heavy Booster has already been caught by the chopsticks on numerous occasions.
The ship landing was precise, meaning that it would have been caught by the tower arms https://t.co/6nbNrRfX9P
— Elon Musk (@elonmusk) July 29, 2026
A ship catch would be a great indication of where SpaceX stands in terms of reusability and launch cadence. A successful catch with relatively no incidents would be a good sign that SpaceX is nearing a more frequent launch of Starship, but also that the reusability of the massive rocket would be something many would expect in the near future.
It is a necessity to make life multiplanetary.
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Elon Musk has updated his timeline for when humans will walk on Mars and for when ships will simply get there.
The objective of getting to Mars has been one of Musk’s biggest goals since becoming a serial entrepreneur and realizing that time on Earth is limited. Musk has said several times he hopes to die on Mars, and not by impact.
Musk now believes that people will be on Mars in “roughly 5 to 7 years.” He said that a Mars lander will get there “a few years sooner.”
People on Mars in roughly 5 to 7 years.
Mars lander a few years sooner.
— Elon Musk (@elonmusk) July 29, 2026
The response from Musk comes after NASA Administrator Jared Isaacman said that SpaceX’s biggest priority is the Moon and not Mars. Because of this, Isaacman conceded that he believes nuclear power and propulsion investments will provide “potentially the pathway with the fewest miracles required to put four people on Mars in the next 10 to 15 years.”
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Of course, this is what NASA can do through taxpayer funding and nuclear investments, he added.
Musk’s grand ambitions are much more optimistic than most, and it is certainly a double-edged sword. This is not the first time timelines for Mars have been somewhat lofty, especially to those normal thinkers like you and me, not super geniuses like Musk.
In fact, the SpaceX and Tesla frontman has said on at least a dozen occasions that we could be on Mars in the coming years. Musk said 2020 would be the big year as early as 2009. In 2020, he was “highly confident” of a landing in 2026, and had even said 2024 in a best-case scenario.
The point is, the range has varied, and it’s anyone’s guess when we’ll get there. This latest adjustment to the timeline is typical of Musk, and while the Moon has seemingly taken priority over Mars, it is still worth mentioning that the ultimate goal is to make life multiplanetary, and it starts potentially with the Red Planet.
SpaceX (NASDAQ: SPCX) got an absolutely crazy price target rating from Raymond James after the company experienced a tough first few weeks following its Initial Public Offering (IPO).
Despite the tumultuous start, SpaceX has plenty of believers, and the company’s massively successful Starship launch last Friday, its 13th test flight of the massive rocket, went so smoothly that Raymond James analysts pushed its price target on the company to roughly 7 times its current trading level.
SpaceX Starship just nailed something it’s never done before
The firm officially put a “Strong Buy” rating and an $800 price target on the stock. It currently trades at around $113. Its all-time high is $225.64, reaching this trading level shortly after shares first went public.
Raymond James’ price target is tied to the firm’s confidence after Starship’s 13th test flight. Analysts at the firm said it was an incremental step that reduces engineering risks, citing the widely successful heat shield test that CEO Elon Musk recently detailed, the smooth deployment of Starlink V3 satellites, and a successful in-space engine relight.
SpaceX also managed to see Starship splash down safely in the Indian Ocean, while the Super Heavy Booster fell down to the Gulf of America with no incidents.
It is interesting to see these launches have such a tremendous impact on the stock and what investors think of it. After SpaceX initially delayed the Starship launch last week, shares fell tremendously. Most probably did not realize that the stand-down is a standard practice, especially if everything is not perfect.
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The mission was initially aborted due to an issue with Raptor engines. This was resolved, and Starship launched last Friday after another delay on Thursday, which was caused by weather.
Now that analysts have seen what SpaceX launches are capable of and how impressive the feat is, firms are adjusting their price targets accordingly, making it known that they have high expectations for the space exploration company.
Elon Musk sheds two new bits of detail on Starship after 13th test launch
Elon Musk updates the SpaceX timeline for Mars
