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
The Boring Company’s latest Tesla tunnel truck mod “fits like a glove”
The Boring Company has modified a Tesla powered tunnel truck to carry freight containers underground.
The Boring Company has found a second job for the Tesla hardware it already runs underground. In a post on X, Elon Musk’s tunneling company showed its latest Prufrock Liner Truck modified to carry a standard 20 foot shipping container. “Using TBC tunnels to transport freight,” the company wrote. “The latest Prufrock Liner Truck (using Tesla Model 3 batteries and drive units) has been modified to carry a standard 20′ shipping container. Fits like a glove!”
The photo shows a red container sitting on a long, low white chassis parked outside, with drive hardware visible at one end. The Boring Company did not say where or when freight hauling would start, which customers it has in mind, or how many trucks it is converting.
Using TBC tunnels to transport freight.
The latest Prufrock Liner Truck (using Tesla Model 3 batteries and drive units) has been modified to carry a standard 20’ shipping container.
Fits like a glove! https://t.co/VV0phWK4fc
— The Boring Company (@boringcompany) October 19, 2026
Until now, the liner trucks have hauled concrete. Teslarati reported in August on Liner Truck 3, which uses Model 3 battery packs and drive units to move more than 22,000 pounds of precast tunnel segments to the boring machine. It has 28 miles of range, tops out at 12 mph, and is piloted remotely from the company’s operations center in Texas. The freight version appears to be the same platform with a different bed, and The Boring Company has not said whether it will also be remotely piloted.
Freight has been on the company’s menu for years. When TBC updated its product lineup in 2021, its freight tunnel was described as sized to fit a standard shipping container, “barely.” The company later used the idea at Tesla’s own factory, where Prufrock 3 dug a tunnel to Giga Texas that now moves finished Cybertrucks away from the production line.
The Boring Company closed a $3 billion Series D in September at a $23 billion valuation, and Teslarati has covered how that money is tied to a UAE tunneling push and a faster Nashville build. In Nashville, Prufrock MB1 and MB2 are mining at the same time, and a third machine is expected to launch in late October. Each machine needs a steady supply of liner trucks, so any design that works for segments and containers alike gives the company more use out of the same Tesla parts.
The Vegas Loop remains the only Boring Company system open to the public, and it moves passengers in Tesla vehicles. A freight service would be a separate product, and the post gave no indication that one is close to launch. For now, it is a truck, a container and a short caption saying they fit together.
Elon Musk said he is planning to give “every one of his SpaceX shares to every kid in America” in 2027, stating that “this will be the first of many.”
SpaceX went public earlier this year, and its stock price has been relatively stable since leveling off shortly after its IPO. Based on its current price, it’s a gift of just over $10 billion to children across the United States.
It appears to be closely related to President Donald Trump’s bank accounts for children, which were set up earlier this year as Trump Accounts.
Just hours earlier, Anthropic had announced the establishment of its Anthropic Public Benefit Fund, “a new wholly-owned entity dedicated entirely to public benefit.” Musk responded by stating he recommended “giving the shares directly to the public,” and that he would be doing it that way.
Just a little bit later, Musk said children across the U.S. would be getting a share from him:
Next year, I will give one of my SpaceX shares to every kid in America.
This will be the first of many.
— Elon Musk (@elonmusk) October 19, 2026
There are roughly 70 million children, meaning someone under the age of 18, in the United States, according to the Federal Interagency Forum on Child and Family Statistics. Musk’s ownership of SpaceX stock shows he has around 849 million Class A shares of SpaceX stock, according to filings with the SEC.
Elon Musk revealed in a post on X that “Permits were impossible to get,” explaining the fate of The Boring Company’s most ambitious East Coast proposal.
The comment responded to a query about what became of his July 20, 2017 announcement that he had “just received verbal govt approval” for an underground Hyperloop connecting New York City, Philadelphia, Baltimore, and Washington, D.C., capable of carrying passengers from the Big Apple to the Nation’s Capital in just 29 minutes.
The Boring Company receives verbal ‘approval’ to build NY to DC Hyperloop tunnel
The 2017 post, which envisioned city-center stations and multiple elevators in each city, sparked immediate scrutiny. Local and state officials in New York, Philadelphia, Baltimore, and D.C. said they had no knowledge of any approval. A White House spokesperson confirmed only “promising conversations” about the transformative infrastructure.
Musk clarified shortly after that there was “still a lot of work” to do for formal approvals.
@cybrtrkguy Permits were impossible to get
— Elon Musk (@elonmusk) October 19, 2026
Limited progress followed, as Maryland Governor Larry Hogan’s administration issued a conditional utility permit and supported work near Fort Meade. In 2018, Washington, D.C., granted a preliminary permit for site preparation and excavation on a vacant lot at 53 New York Ave. NE in the NoMa neighborhood, which The Boring Company said could become a station.
A draft environmental assessment for a D.C.-Baltimore segment was released in 2019. Yet, by April 2021, the company had removed the project from its website, and the Federal Highway Administration reported receiving no indication of further interest. Communication with Maryland officials had ceased.
The full corridor would have required coordination among the District of Columbia, Maryland, Pennsylvania, New York, the Federal Highway Administration, the Army Corps of Engineers, the National Park Service, and other agencies.
Environmental reviews under the National Environmental Policy Act, utility clearances, and approvals for novel infrastructure added to the overall complexity of the project and its approval.
Speculation on the permitting barriers centers around a few factors, but a multi-state, multi-level route involving unproven high-speed vacuum-tube technology inherently triggers exhaustive safety, environmental, and engineering reviews that can stretch for years, even for conventional projects.
There are also other elements, of course, like officials who may face political exposure if a privately funded, untested system encountered anything such as cost overruns, delays, or safety issues. On the outset of this project, there were limited things such as engineering plans or demonstrated technology maturity, which also added to the potential skepticism.
The East Coast vision for Boring Co., once framed as a privately funded revolution that could reshape Northeast travel, quietly ended without construction of the promised network. Musk’s recent statement frames the outcome as a regulatory impasse, unfortunate but not unexpected.
The Boring Company’s latest Tesla tunnel truck mod “fits like a glove”
Elon Musk will give ‘every kid in America’ a SpaceX share in 2027
Elon Musk reveals why Boring Co’s biggest East Coast project never happened
SpaceX reveals how its 1 Million AI satellite network will work and prevent space collisions
Tesla Roadster: Three configs, one can fly, 0-60 in 0.8 seconds
