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Tesla-funded researchers discover surprising detail about lithium-ion battery discharges
A potentially crucial reason behind lithium-ion batteries’ tendency to self-discharge has seemingly been discovered by researchers at the Tesla-funded battery research center at Dalhousie University. What’s quite remarkable was that the group’s findings were amazingly simple yet potentially profound.
Electronic products such as smartphones and laptops tend to self-discharge over time. It’s an all-too-familiar scenario, where a device loses battery charge despite not being used for a period of time. But while this is considered normal today, researchers from Dalhousie University may have discovered the culprit for self-discharging lithium-ion batteries.
Dr. Michael Metzger, an assistant professor and the Herzberg-Dahn chair and in the Department of Physics and Atmospheric Science at Dalhousie University, noted that a commercial tape that holds electrodes together in lithium-ion batteries could be a key contributor to the self-discharging process.
“In commercial battery cells, there is tape — like Scotch tape — that holds the electrodes together, and there is a chemical decomposition of this tape, which creates a molecule that leads to the self-discharge. In our laboratory, we do many highly complex experiments to improve batteries, but this time we discovered a very simple thing. It’s a very simple thing — it is in every plastic bottle, and no one would have thought that this has such a huge impact on how the lithium-ion cells degrade,” Dr. Metzger said.
To understand lithium-ion battery cells and their self-discharging behaviors, Dr. Metzger and his team opened up several cells and exposed them to various temperatures. To their surprise, the team found that the electrolyte solution in the cell was bright red. Exploring further, the team placed cells with common electrolyte solution into ovens at four different temperatures. Four different oven temperatures were used, ranging from 25°C to 70°C. The cell sample at 25°C remained clear, while the sample at 55°C turned light brown, and the one at 70°C became blood red. The team then performed a chemical analysis to examine the composition of the electrolyte.
Following are the team’s observations.
“That’s when (the researchers) found that the polyethylene terephthalate, or PET, in the tape decomposes and creates the molecule that leads to the self-discharge. The molecule is called a redox shuttle because it can travel to the positive side of the electrode, then to the negative side and then back to the positive side. So, it shuttles between the electrodes and that creates the self-discharge, just like lithium is supposed to do. The problem is that the shuttle molecule is doing it all the time in the background, even when no lithium is supposed to move when the battery just sitting there.”
“It’s something we never expected because no one looks at these inactive components, these tapes and plastic foils in the battery cell but it really needs to be considered if you want to limit side reactions in the battery cell,” Dr. Metzger said.
Dr. Metzger and his team’s findings can be found below.
Buechele 2023 J. Electrochem. Soc. 170 010518 by Simon Alvarez on Scribd
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Tesla stock (NASDAQ: TSLA) closed at an all-time high on Tuesday, jumping over 3 percent during the day and finishing at $489.88.
The price beats the previous record close, which was $479.86.
Shares have had a crazy year, dipping more than 40 percent from the start of the year. The stock then started to recover once again around late April, when its price started to climb back up from the low $200 level.
This week, Tesla started to climb toward its highest levels ever, as it was revealed on Sunday that the company was testing driverless Robotaxis in Austin. The spike in value pushed the company’s valuation to $1.63 trillion.
Tesla Robotaxi goes driverless as Musk confirms Safety Monitor removal testing
It is the seventh-most valuable company on the market currently, trailing Nvidia, Apple, Alphabet (Google), Microsoft, Amazon, and Meta.
Shares closed up $14.57 today, up over 3 percent.
The stock has gone through a lot this year, as previously mentioned. Shares tumbled in Q1 due to CEO Elon Musk’s involvement with the Department of Government Efficiency (DOGE), which pulled his attention away from his companies and left a major overhang on their valuations.
However, things started to rebound halfway through the year, and as the government started to phase out the $7,500 tax credit, demand spiked as consumers tried to take advantage of it.
Q3 deliveries were the highest in company history, and Tesla responded to the loss of the tax credit with the launch of the Model 3 and Model Y Standard.
Additionally, analysts have announced high expectations this week for the company on Wall Street as Robotaxi continues to be the focus. With autonomy within Tesla’s sights, things are moving in the direction of Robotaxi being a major catalyst for growth on the Street in the coming year.
Elon Musk
Tesla needs to come through on this one Robotaxi metric, analyst says
“We think the key focus from here will be how fast Tesla can scale driverless operations (including if Tesla’s approach to software/hardware allows it to scale significantly faster than competitors, as the company has argued), and on profitability.”
Tesla needs to come through on this one Robotaxi metric, Mark Delaney of Goldman Sachs says.
Tesla is in the process of rolling out its Robotaxi platform to areas outside of Austin and the California Bay Area. It has plans to launch in five additional cities, including Houston, Dallas, Miami, Las Vegas, and Phoenix.
However, the company’s expansion is not what the focus needs to be, according to Delaney. It’s the speed of deployment.
The analyst said:
“We think the key focus from here will be how fast Tesla can scale driverless operations (including if Tesla’s approach to software/hardware allows it to scale significantly faster than competitors, as the company has argued), and on profitability.”
Profitability will come as the Robotaxi fleet expands. Making that money will be dependent on when Tesla can initiate rides in more areas, giving more customers access to the program.
There are some additional things that the company needs to make happen ahead of the major Robotaxi expansion, one of those things is launching driverless rides in Austin, the first city in which it launched the program.
This week, Tesla started testing driverless Robotaxi rides in Austin, as two different Model Y units were spotted with no occupants, a huge step in the company’s plans for the ride-sharing platform.
Tesla Robotaxi goes driverless as Musk confirms Safety Monitor removal testing
CEO Elon Musk has been hoping to remove Safety Monitors from Robotaxis in Austin for several months, first mentioning the plan to have them out by the end of 2025 in September. He confirmed on Sunday that Tesla had officially removed vehicle occupants and started testing truly unsupervised rides.
Although Safety Monitors in Austin have been sitting in the passenger’s seat, they have still had the ability to override things in case of an emergency. After all, the ultimate goal was safety and avoiding any accidents or injuries.
Goldman Sachs reiterated its ‘Neutral’ rating and its $400 price target. Delaney said, “Tesla is making progress with its autonomous technology,” and recent developments make it evident that this is true.
Investor's Corner
Tesla gets bold Robotaxi prediction from Wall Street firm
Last week, Andrew Percoco took over Tesla analysis for Morgan Stanley from Adam Jonas, who covered the stock for years. Percoco seems to be less optimistic and bullish on Tesla shares, while still being fair and balanced in his analysis.
Tesla (NASDAQ: TSLA) received a bold Robotaxi prediction from Morgan Stanley, which anticipates a dramatic increase in the size of the company’s autonomous ride-hailing suite in the coming years.
Last week, Andrew Percoco took over Tesla analysis for Morgan Stanley from Adam Jonas, who covered the stock for years. Percoco seems to be less optimistic and bullish on Tesla shares, while still being fair and balanced in his analysis.
Percoco dug into the Robotaxi fleet and its expansion in the coming years in his latest note, released on Tuesday. The firm expects Tesla to increase the Robotaxi fleet size to 1,000 vehicles in 2026. However, that’s small-scale compared to what they expect from Tesla in a decade.
Tesla expands Robotaxi app access once again, this time on a global scale
By 2035, Morgan Stanley believes there will be one million Robotaxis on the road across multiple cities, a major jump and a considerable fleet size. We assume this means the fleet of vehicles Tesla will operate internally, and not including passenger-owned vehicles that could be added through software updates.
He also listed three specific catalysts that investors should pay attention to, as these will represent the company being on track to achieve its Robotaxi dreams:
- Opening Robotaxi to the public without a Safety Monitor. Timing is unclear, but it appears that Tesla is getting closer by the day.
- Improvement in safety metrics without the Safety Monitor. Tesla’s ability to improve its safety metrics as it scales miles driven without the Safety Monitor is imperative as it looks to scale in new states and cities in 2026.
- Cybercab start of production, targeted for April 2026. Tesla’s Cybercab is a purpose-built vehicle (no steering wheel or pedals, only two seats) that is expected to be produced through its state-of-the-art unboxed manufacturing process, offering further cost reductions and thus accelerating adoption over time.
Robotaxi stands to be one of Tesla’s most significant revenue contributors, especially as the company plans to continue expanding its ride-hailing service across the world in the coming years.
Its current deployment strategy is controlled and conservative to avoid any drastic and potentially program-ruining incidents.
So far, the program, which is active in Austin and the California Bay Area, has been widely successful.
Tesla stock closes at all-time high on heels of Robotaxi progress
Tesla needs to come through on this one Robotaxi metric, analyst says
