

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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Investor's Corner
Tesla delivers 384,000 vehicles in Q2 2025, deploys 9.6 GWh in energy storage
The quarter’s 9.6 GWh energy storage deployment marks one of Tesla’s highest to date.

Tesla (NASDAQ: TSLA) has released its Q2 2025 vehicle delivery and production report. As per the report, the company delivered over 384,000 vehicles in the second quarter of 2025, while deploying 9.6 GWh in energy storage. Vehicle production also reached 410,244 units for the quarter.
Model 3/Y dominates output, ahead of earnings call
Of the 410,244 vehicles produced during the quarter, 396,835 were Model 3 and Model Y units, while 13,409 were attributed to Tesla’s other models, which includes the Cybertruck and Model S/X variants. Deliveries followed a similar pattern, with 373,728 Model 3/Ys delivered and 10,394 from other models, totaling 384,122.
The quarter’s 9.6 GWh energy storage deployment marks one of Tesla’s highest to date, signaling continued strength in the Megapack and Powerwall segments.
Year-on-year deliveries edge down, but energy shows resilience
Tesla will share its full Q2 2025 earnings results after the market closes on Wednesday, July 23, 2025, with a live earnings call scheduled for 4:30 p.m. CT / 5:30 p.m. ET. The company will publish its quarterly update at ir.tesla.com, followed by a Q&A webcast featuring company leadership. Executives such as CEO Elon Musk are expected to be in attendance.
Tesla investors are expected to inquire about several of the company’s ongoing projects in the upcoming Q2 2025 earnings call. Expected topics include the new Model Y ramp across the United States, China, and Germany, as well as the ramp of FSD in territories outside the US and China. Questions about the company’s Robotaxi business, as well as the long-referenced but yet to be announced affordable models are also expected.
News
Tesla China breaks 8-month slump by selling 71,599 vehicles wholesale in June
Tesla China’s June numbers were released by the China Passenger Car Association (CPCA) on Tuesday.

Tesla China was able to sell 71,599 vehicles wholesale in June 2025, reversing eight consecutive months of year-over-year declines. The figure marks a 0.83% increase from the 71,599 vehicles sold wholesale in June 2024 and a 16.1% jump compared to the 61,662 vehicles sold wholesale in May.
Tesla China’s June numbers were released by the China Passenger Car Association (CPCA) on Tuesday.
Tesla China’s June results in focus
Tesla produces both the Model 3 and Model Y at its Shanghai Gigafactory, which serves as the company’s primary vehicle export hub. Earlier this year, Tesla initiated a changeover for its best-selling vehicle, the Model Y, resulting in a drop in vehicle sales during the first and second quarters.
Tesla’s second-quarter China sales totaled 191,720 units including exports. While these numbers represent a 6.8% year-over-year decline for Tesla China, Q2 did show sequential improvement, rising about 11% from Q1 2025, as noted in a CNEV Post report.
For the first half of the year, Tesla sold 364,474 vehicles wholesale. This represents a 14.6% drop compared to the 426,623 units sold wholesale in the first half of 2024.
China’s competitive local EV market
Tesla’s position in China is notable, especially as the new Model Y is gaining ground in the country’s BEV segment. That being said, Tesla is also facing competition from impressive local brands such as Xiaomi, whose new YU7 electric SUV is larger and more affordable than the Model Y.
The momentum of the YU7 is impressive, as the vehicle was able to secure 200,000 firm orders within three minutes and over 240,000 locked-in orders within 18 hours. Xiaomi’s previous model, the SU7 electric sedan, which is aimed at the Tesla Model 3, also remains popular, with June deliveries surpassing 25,000 units for the ninth straight month.
While China’s EV market is getting more competitive, Tesla’s new Model Y is also ramping its production and deliveries. Needless to say, Tesla China’s results for the remaining two quarters of 2025 will be very interesting.
Elon Musk
Tesla reveals it is using AI to make factories more sustainable: here’s how
Tesla is using AI in its Gigafactory Nevada factory to improve HVAC efficiency.

Tesla has revealed in its Extended Impact Report for 2024 that it is using Artificial Intelligence (AI) to enable its factories to be more sustainable. One example it used was its achievement of managing “the majority of the HVAC infrastructure at Gigafactory Nevada is now AI-controlled” last year.
In a commitment to becoming more efficient and making its production as eco-friendly as possible, Tesla has been working for years to find solutions to reduce energy consumption in its factories.
For example, in 2023, Tesla implemented optimization controls in the plastics and paint shops located at Gigafactory Texas, which increased the efficiency of natural gas consumption. Tesla plans to phase out natural gas use across its factories eventually, but for now, it prioritizes work to reduce emissions from that energy source specifically.
It also uses Hygrometric Control Logic for Air Handling Units at Giafactory Berlin, resulting in 17,000 MWh in energy savings each year. At Gigafactory Nevada, Tesla saves 9.5 GWh of energy through the use of N-Methylpyrrolidone refineries when extracting critical raw material.
Perhaps the most interesting way Tesla is conserving energy is through the use of AI at Gigafactory Nevada, as it describes its use of AI to reduce energy demand:
“In 2023, AI Control for HVAC was expanded from Nevada and Texas to now include our Berlin-Brandenburg and Fremont factories. AI Control policy enables HVAC systems within each factory to work together to process sensor data, model factory dynamics, and apply control actions that safely minimize the energy required to support production. In 2024, this system achieved two milestones: the majority of HVAC infrastructure at Gigafactory Nevada is now AI-controlled, reducing fan and thermal energy demand; and the AI algorithm was extended to manage entire chiller plants, creating a closed-loop control system that optimizes both chilled water consumption and the energy required for its generation, all while maintaining factory conditions.”
Tesla utilizes AI Control “primarily on systems that heat or cool critical factory production spaces and equipment.” AI Control communicates with the preexisting standard control logic of each system, and any issues can be resolved by quickly reverting back to standard control. There were none in 2024.
Tesla says that it is utilizing AI to drive impact at its factories, and it has proven to be a valuable tool in reducing energy consumption at one of its facilities.
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