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
ARK’s SpaceX IPO Guide makes a compelling case on why $1.75T may not be the ceiling
ARK Invest breaks down six reasons SpaceX’s $1.75 trillion IPO valuation may be justified.
ARK Invest, which holds SpaceX as its largest Venture Fund position at 17% of net assets, has published a detailed investor guide to why a SpaceX IPO may be grounded in a $1.75 trillion target valuation.
The financial case starts with Starlink, SpaceX’s satellite internet constellation, which has surpassed 10 million active subscribers globally as of early 2026, with 2026 revenue projected to exceed $20 billion. ARK’s research puts the total satellite connectivity market opportunity at roughly $160 billion annually at scale, and Starlink is adding customers faster than any telecom network in history. That growth alone would justify a substantial valuation.
Additionally, ARK notes that SpaceX has reduced the cost per kilogram to orbit from roughly $15,600 in 2008 to under $1,000 today through reusable Falcon 9 hardware. A fully operational Starship targeting sub-$100 per kilogram would represent a significant cost decline and open markets that do not currently exist. SpaceX executed a staggering 165 missions in 2025 and now accounts for approximately 85% of all global orbital launches. That infrastructure position took decades to build and would be nearly impossible to replicate at comparable cost.
SpaceX officially acquires xAI, merging rockets with AI expertise
The February 2026 merger with xAI added a layer to the valuation that straightforward financial models struggle to capture. ARK argues that at sub-$100 launch costs, orbital data centers could deliver compute roughly 25% cheaper than ground-based alternatives, without power grid delays, permitting friction, or land constraints. Musk has stated a goal of deploying 100 gigawatts of AI computing capacity per year from orbit.
The $1.75 trillion figure itself is not a conventional earnings multiple. At roughly 95x trailing revenue, it prices in Starlink’s adoption curve, Starship’s cost trajectory, and the orbital compute thesis together. The public S-1 prospectus, due at least 15 days before the June roadshow, will give investors their first complete look at the financials to test those assumptions. ARK’s position is that the track record earns the benefit of the doubt. Fully reusable rockets were considered unrealistic for years. Starlink was considered financially unviable. Both happened on timelines that surprised skeptics.
Elon Musk
Ford CEO Farley says Tesla is not who to look at for EV expertise
Interestingly, Farley has been one of the most hellbent CEOs in terms of a legacy automaker standpoint to push the EV effort. It did not go according to plan, as Ford took a $19.5 billion charge and retreated from its EV push in late 2025.
Ford CEO Jim Farley said in a recent podcast interview that Tesla is not who Americans should look at to beat Chinese carmakers.
The comments have sparked quite a bit of outrage from Tesla fans on X, the social media platform owned by Elon Musk.
Farley said that Chinese automakers are better examples of how to beat competitors. He said (via the Rapid Response Podcast):
“If you’re an American and you want us to beat the Chinese in the car business, you’re all going to want to pay attention, not necessarily to Tesla. Nothing against Tesla—they’ve been doing great—but they really don’t have an updated vehicle. The best in the business for us, cost-wise and competition-wise, supply chain, manufacturing expertise, and the I.P. in the vehicle, was really BYD. In this next cycle of EV customers in the U.S., they want pickups and utilities and all these different body styles. But they want them at $30,000, not $50,000. Like the first inning, they want them affordably.”
Despite Farley’s synopsis, it is worth mentioning that Tesla had the best-selling passenger vehicle in the world last year, and in China in March, as the Model Y continued its global dominance over other vehicles.
Musk responded to Farley’s comments by stating:
“This is before Supervised FSD is approved in China. Limiting factor is production output in Shanghai.”
This is before supervised FSD is approved in China. Limiting factor is production output in Shanghai.
— Elon Musk (@elonmusk) April 19, 2026
Interestingly, Farley has been one of the most hellbent CEOs in terms of a legacy automaker standpoint to push the EV effort. It did not go according to plan, as Ford took a $19.5 billion charge and retreated from its EV push in late 2025.
Ford cancels all-electric F-150 Lightning, announces $19.5 billion in charges
Instead, Ford is “doubling down on its affordable” EVs and said it would pivot from its previous plans.
Reaction from Tesla fans was pretty much how you would expect. Many said they have lost a lot of respect for Farley after his comments; others believe he is the last CEO anyone should be taking advice on EVs from.
Nevertheless, Farley’s plans are bold and brash; many consider Tesla the most ideal company to replicate EV efforts from. It will be interesting to see if Ford can rebound from this big adjustment, and hopefully, Farley’s plans to replicate efforts from BYD work out the way he hopes.
Elon Musk
SpaceX wins its first MARS contract but it comes with a catch
NASA awarded SpaceX a $175 million Mars rover contract while the White House proposes cutting the mission.
NASA just signed a $175.7 million contract with SpaceX to launch a Mars rover that the White House is simultaneously trying to defund. The contract, awarded on April 16, 2026, tasks SpaceX’s Falcon Heavy with launching the European Space Agency’s (ESA) Rosalind Franklin rover from Kennedy Space Center in Florida, no earlier than late 2028. It would mark the first time SpaceX has ever sent a payload to Mars.
Under NASA’s Rosalind Franklin Support and Augmentation project, known as ROSA, the agency is providing braking engines for the rover’s descent stage, radioisotope heater units that use decaying plutonium to keep the rover warm on the Martian surface, additional electronics, and a mass spectrometer instrument, as noted by SpaceNews.
Those nuclear heating units are the reason an American rocket was required at all. U.S. export controls on radioisotope technology mean any payload carrying them must launch on a domestic vehicle, which narrowed the field to SpaceX and United Launch Alliance. Falcon Heavy’s pricing made it the practical choice.
SpaceX is quietly becoming the U.S. Military’s only reliable rocket
Falcon Heavy debuted in February 2018 and has 11 launches to its record. The rocket has not flown since October 2024, when it sent NASA’s Europa Clipper toward Jupiter. The three-core design, built from modified Falcon 9 first stages, gives it the lift capacity needed for deep space planetary missions that a single Falcon 9 cannot reach.
The Rosalind Franklin rover has been sitting in storage in Europe for years. It was originally due to launch in 2022 as a joint mission with Russia, but Russia’s invasion of Ukraine ended that partnership, leaving the rover built but stranded without a launch vehicle or landing hardware. NASA stepped back in through a 2024 agreement with ESA to rescue the mission. The rover is designed to drill up to two meters below the Martian surface in search of evidence of past life, a science objective no previous mission has attempted at that depth.
The contradiction at the center of this story is hard to ignore. The White House’s fiscal year 2027 budget proposal included no funding for ROSA and did not mention the mission at all in the detailed congressional justification document released April 3.
Musk has long argued that reaching Mars is not optional. “We don’t want to be one of those single planet species, we want to be a multi-planet species.” Whether this particular mission survives Washington’s budget fight, the Falcon Heavy contract means SpaceX is now formally on record as the rocket that could get humanity’s next Mars science mission off the ground.
The timing of this contract carries extra weight given that SpaceX filed confidentially with the SEC in early April and is targeting an IPO roadshow in the week of June 8. It would be the largest public offering in history.
ARK’s SpaceX IPO Guide makes a compelling case on why $1.75T may not be the ceiling
Ford CEO Farley says Tesla is not who to look at for EV expertise
