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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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Tesla’s Cybercab has taken a significant step toward production with new technical details emerging from 2026 EPA certification documents.
The filings, which include a Certificate of Conformity issued in late May, provide the most comprehensive public look yet at the purpose-built autonomous vehicle designed for high-volume, low-cost ride-hailing operations.
At its core, the Cybercab is a front-wheel-drive electric vehicle powered by a single 163 kW (219 horsepower) AC permanent magnet motor. Despite its modest output, prioritizing efficiency and cost over neck-snapping acceleration, the vehicle boasts a strong power-to-weight ratio thanks to its lightweight curb weight of 3,113 pounds and a GVWR of 3,730 pounds.
It operates on a 326-volt electrical architecture with a compact ~48 kWh lithium-ion battery pack. The standout revelation is the vehicle’s exceptional efficiency, which Tesla has routinely flexed in the past.
EPA lab tests list an equivalent all-electric range of 418 miles combined and 375 miles on the highway. Tesla has previously targeted around 300 miles of real-world range, and analysts expect the final EPA-rated figure to land near 280-300 miles after adjustment factors.
At a certified 165 Wh/mi in earlier testing, the Cybercab is reportedly the most efficient EV ever produced, significantly outperforming vehicles like the Lucid Air Pure.
New information about @Tesla‘s Cybercab has been revealed in public EPA documents.
• Front-wheel drive
• Battery capacity: ~48 kWh
• 219 horsepower
• Curb weight: 3,113 lbs
• GVWR: 3,730 lbs
• Motor power: 163kW
• Voltage: 326vEquivalent All Electric Range is listed at… pic.twitter.com/D4gkJJTj25
— Sawyer Merritt (@SawyerMerritt) June 15, 2026
This efficiency stems from deliberate design choices tailored for robotaxi duty. The two-seater features a highly aerodynamic shape, minimal weight, which is aided by structural battery integration of what are likely 4680 cells, and no steering wheel or pedals in its fully autonomous configuration.
For ride-hailing fleets, where average trips are short, and can be just five or ten miles, the smaller battery enables faster charging cycles, lower material costs, and reduced vehicle price, a key to Tesla’s goal of a ~$30,000 production cost.
Implications for Autonomous Mobility
These specs underscore Tesla’s strategy: maximize utilization and minimize operating expenses. A ~48 kWh pack could support dozens of short rides per charge, with energy costs potentially dropping below 20 cents per mile at scale. Front-wheel drive simplifies manufacturing and maintenance compared to dual-motor AWD setups in passenger Teslas.
The 219 hp motor provides ample performance for urban and highway speeds without excess, addressing questions about why such power is needed in a “slow” autonomous vehicle. Quick merges and hill climbing still matter for safety and passenger comfort.
Production has already begun at Giga Texas, with EPA certification clearing the path for U.S. deployment. While unsupervised Full Self-Driving remains the critical hurdle, these details paint a compelling picture of a vehicle engineered from the ground up for the robotaxi future: affordable to build, cheap to run, and capable of delivering strong range on a fraction of the battery capacity found in today’s EVs.
As Tesla ramps toward volume output, the Cybercab could reshape urban transportation economics.
Tesla Cybercab, the all-electric ride-hailing-geared vehicle void of a steering wheel and pedals, has achieved a significant regulatory milestone. The vehicle has officially secured an EPA Certificate of Conformity for the 2026 Cybercab, classifying it as a battery electric Zero Emission Vehicle (ZEV).
This certification confirms full compliance with federal Clean Air Act emission standards, paving the way for legal sales and operation across the United States.
A Certificate of Conformity (CoC) is a critical document issued by the U.S. Environmental Protection Agency (EPA) to vehicle manufacturers. It certifies that a specific class of vehicles meets all applicable federal emission requirements for the model year.
We have reported on several of them in the past, and it’s a good sign that a vehicle is close to being available to the public.
Every vehicle sold in the U.S. must carry this approval, which covers exhaust emissions, evaporative emissions, and refueling standards. For battery electric vehicles like the Cybercab, it verifies zero tailpipe emissions and compliance with stringent testing protocols. The certificate, issued and effective May 26, 2026, was part of the EPA’s recent bi-weekly upload, detailing the Cybercab’s evaporative/refueling family and exhaust compliance.
It also revealed some other very important information, as the Cybercab’s “Charge Depleting Range” was rated at just over 418 miles. This was for city driving, while the highway range depletion test revealed just over 375 miles of range:
Highway miles for Charge Depleting Range was just over 375 miles
— TESLARATI (@Teslarati) June 15, 2026
This EPA approval is a foundational step for Tesla’s autonomous ambitions. While emission certification is standard for any new EV, it signals that the Cybercab is progressing through the full federal compliance process.
Tesla has already equipped prototypes with federal compliance stickers affirming adherence to safety, bumper, and theft-prevention standards via self-certification under FMVSS rules. This bypasses the traditional 2,500-vehicle exemption cap that previously constrained low-volume autonomous testing.
Production of the Cybercab ramped up at Giga Texas starting in early 2026, with volume targets aiming for hundreds of units per week and long-term ambitions of millions annually. The two-seater, steer-by-wire vehicle, lacking a steering wheel and pedals, features a sleek, minimalist design optimized for Robotaxi service.
Priced under $30,000 at unveiling, it promises operating costs as low as $0.20–$0.40 per mile once scaled. Tesla has routinely flexed it as one of the most efficient vehicles of all time.
Regulatory progress extends beyond the EPA. The NHTSA has streamlined approvals for control-free vehicles, benefiting the Cybercab. Tesla operates supervised and unsupervised Robotaxi services in Texas cities like Austin, Dallas, and Houston using its fleet. California recently updated rules for driverless operations, including enforcement mechanisms for violations. Additional state-by-state approvals will be needed for nationwide rollout.
This EPA green light reduces a key barrier, building confidence among regulators, partners, and investors.
It underscores Tesla’s strategy of designing the Cybercab from the ground up for full compliance rather than retrofitting existing platforms. Challenges remain in scaling unsupervised autonomy, mapping approvals, and public acceptance, but the certification marks tangible momentum toward transforming urban mobility.
With prototypes already testing on public roads and production accelerating, the Cybercab edges closer to redefining transportation. Tesla’s integrated approach—combining hardware simplicity, software prowess, and regulatory diligence—positions it uniquely in the robotaxi race.
SpaceX executed its first Falcon 9 launch since going public on June 15, a routine yet symbolically powerful Starlink mission from Vandenberg Space Force Base in California.
Liftoff of the Falcon 9 booster B1093, on its 14th flight, occurred at approximately 8:34 a.m. PDT from Space Launch Complex 4E (SLC-4E), deploying 24 Starlink V2 Mini Optimized satellites into low-Earth orbit.
The first stage successfully landed on the droneship “Of Course I Still Love You” in the Pacific Ocean, underscoring the company’s unmatched reusability track record.
Watch Falcon 9 launch 24 @Starlink satellites to orbit from California https://t.co/meDwb05qOE
— SpaceX (@SpaceX) June 15, 2026
This mission comes just three days after SpaceX’s historic IPO on June 12, which shattered records as the largest ever. The company raised $75 billion by pricing shares at $135, with trading under ticker SPCX on Nasdaq opening at $150 and closing at $160.95—a 19 percent gain—valuing SpaceX at over $2.1 trillion.
The launch highlights the seamless transition from private innovator to public powerhouse. SpaceX, founded in 2002, has revolutionized access to space with over 650 Falcon 9 flights and a massive Starlink constellation now serving millions globally.
As a public company, it faces new pressures: quarterly earnings, shareholder scrutiny, and expectations to accelerate Starship development for Mars ambitions and deeper NASA partnerships. Yet the market response signals strong confidence in its dominance, as launch costs are slashed by 95 percent, rapid satellite deployment, and a backlog of government and commercial contracts.
SpaceX maintains bold advertising push for Starlink, contrasting Tesla’s minimalistic approach
Analysts view today’s flight as business as usual, but it carries extra weight. With shares volatile in early trading days, successful operations reassure investors that core capabilities remain unaffected by public status.
SpaceX now operates under heightened transparency, potentially unlocking capital for ambitious goals like Starship orbital tests and global broadband expansion.
Challenges loom, including regulatory hurdles for megaconstellations, competition in reusable rockets, and orbital debris concerns. Nevertheless, this morning’s flawless execution reinforces SpaceX’s trajectory.
As Musk often notes, the company’s mission—to make humanity multiplanetary—now aligns with Wall Street’s growth demands. The stars, it seems, are aligning for both.
Tesla Cybercab specs revealed: range, curb weight, range ratings, and more
Tesla Cybercab snags huge regulatory green light that readies it for public roads
