Tesla Model S 85D e P85D 2015

[Wilhem275]

Non comprendo perché il consumo aumenti così tanto già a partire d velocità piuttosto basse in teoria, se stessimo parlando di consumo a velocità circa fissa, le conseguenze più serie dovrebbero farsi vedere all'incirca a partire dalle 60 mph.

Inoltre, se il limite fosse principalmente aerodinamico, si avrebbe un peggiormamento col quadrato della velocità, mentre in quel grafico la perdita è minore all'aumentare della velocità, proprio non capisco.

Ma anche se fosse una questione di efficienza del powertrain: per mandare avanti a velocità costante un'auto serve una potenza relativamente limitata, insomma niente di tragico rispetto ad una guidata nel traffico.

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This is Tesla's plan for a cheaper car

The newest direction Tesla is headed toward is silicon.Tesla’s road to a cheaper electric car has always appeared to lead straight to Reno, where the electric automaker is building a $5 billion gigafactory designed with enough capacity to reduce the per-kilowatt-hour cost of its lithium-ion battery packs by over 30% by the end of 2017.

Many companies are already planning concepts around the promise of cheaper, higher-capacity batteries. But, it turns out that TeslaTSLA -0.67% has more than one path toward its ultimate goal of an electric car that’s 50% cheaper than its luxury Model S.

The newest direction Tesla is headed toward is silicon—not the Valley, but the material that is changing the way batteries are made. Tesla’s new 90 kilowatt-hour battery pack—an upgrade announced Friday that increases pack energy by 5% and adds about 15 miles of range to its vehicles—might look the same. But the inclusion of silicon is an advance for lithium-ion technology.

During a call with reporters last week, CEO Elon Musk said the company had improved the battery by shifting the cell chemistry for the pack to partially use silicon in the anode.

“This is just sort of a baby step in the direction of using silicon in the anode,” Musk said during the call. “We’re still primarily using synthetic graphite, but over time we’ll be increasing silicon in the anode.”

For the unfamiliar, this might sound like minor tinkering. It’s actually an important and challenging step for Tesla (and other battery manufacturers) that could lead to a better, cheaper battery.

“It’s a race among the battery makers to get more and more silicon in,” said Jeff Dahn, a leading lithium-ion battery researcher and professor at Dalhousie University in Nova Scotia who recentlysigned a 5-year exclusive partnership with Tesla. “The number of researchers around the world working on silicon for lithium-ion cells is mindboggling. A large number of academics and industrial folks are working really hard on this problem.”

Batteries 101

A battery contains two electrodes: an anode (negative) on one side and a cathode (positive) on the other. An electrolyte, essentially the courier that moves ions between the electrodes when charging and discharging, sits in the middle.

Graphite is commonly used as the anode in commercial lithium-ion batteries. However, a silicon anode can store about 10 times more (per unit volume) lithium ions. In theory, if you replaced a lot of graphite in the cell with silicon, the thickness of the graphite negative electrode could be reduced. There would be more space to add more active material and you could, in turn, increase the energy density—or the amount of energy that can be stored in a battery per its volume—of the cell.

In other words, you could pack more energy in the same space. Plus, the silicon used in the battery space doesn’t need to be the same quality as what’s used in solar cells and integrated circuits, which means it’s cheaper. The more silicon you put in the battery, the easier it is to drive costs down.

That’s the goal of battery makers everywhere: to improve their product while reducing costs.

Sounds easy enough, right? Hardly, says Dahn, who is currently working on a project funded by 3M and the Natural Sciences and Engineering Research Council of Canada to develop longer lasting, lower cost lithium-ion battery cells. Their exclusive partnership with Tesla will begin in June 2016, once Dahn has completed the 3M research project.

The trick is that when you add lithium to the silicon you end up with almost five times the original number of atoms you started with. And that causes all kinds of problems.

An Electrode Particle Walks Into a Party

Think of the battery electrode as a room and a lot of electrode particles—or people— are packed in there for a party, Dahn explains. Now imagine that everybody in that room suddenly becomes obese; the people aren’t going to fit anymore.

“If everyone is already packed in there and they all become 400 pounds, you’re in big trouble,” says Dahn.

This is what happens when all the particles in the electrode are silicon. But if only a few people in the room become obese, it’s not so bad because they can shuffle around and make enough space for these obese folks.

“This is why only a small amount of silicon is being initially added,” Dahn says.

That’s not the only issue with using silicon. To take the crowded room analogy a step further, imagine these obese people (or electrode particles) shrink when the battery is charged and then blow up again when it’s discharged. That enormous volume change causes another issue. The surface of every silicon particle is in contact with the electrolyte, and the protective film on the silicon is continually being stretched as the size of those particles change. When it shrinks it can flake off, which can impact the lifespan of the battery.

This means that the more silicon you put in, the more challenging it is to maintain cycle life, Dahn says.

Which brings us to where battery makers and researchers are today.

“Right now, you put in a touch—a little pixie dust—and it’s tolerable,” says Dahn. “Over the years, more and more will go in and that’s a good thing because it means these products are going to improve and get better.”

Dahn’s research team aims to increase both the energy density and the lifespan of lithium-ion cells, which could, in turn, help drive down costs in automotive and grid energy storage applications. They aren’t the only ones. “There are quite a few companies around the world that are starting to put silicon in the negative electrode,” explains Dahn. “And it’s not just Panasonic, Tesla’s supplier. Samsung and other companies around the world are doing this too.”

Most batteries today, even those in consumer electronics, have tiny amounts of silicon, says Sam Jaffe, a longtime analyst, formerly of Navigant Research, and now CEO of startup Cygnus Energy Storage.

The question is what percentage of silicon is Tesla using. The industry standard is between 1 to 3% silicon in battery recipes, Jaffe says. He believes Tesla has figured out how to use more.

“For them to have made a significant change in the energy density of the battery and then to publicly say it’s the silicon increase makes me think—and this is speculation now—that they’ve made progress getting higher percentages of silicon into the cell,” Jaffe says.

Model X and Tesla as a Supplier

“There’s a lot of incentive to continue to improve this battery technology for everyone in the industry,” Karl Brauer, a senior analyst at Kelley Blue Book, told Fortune. “It’s certainly the lifeblood for Tesla.”

Tesla had to increase the battery capacity for the highly anticipated Model X SUV because it’s heavier and without it, the vehicle would have lost range, Brauer says.

Brauer also believes the focus on battery tech isn’t just to improve the cars, but to set the company up as a supplier.

With many companies already anticipating the use of cheaper, more powerful lithium-ion batteries and competing to apply that technology to residential and commercial power grid applications, Tesla’s move could put them at the forefront of a newly revolutionized energy industry.

Via Time

Praticamente dicono che vogliono aumentare la quantità di silicone nelle batterie. Non sono pratico del settore e quindi non ho ben capito bene ma credo sia interessante!

[v13]

Via Time

Praticamente dicono che vogliono aumentare la quantità di silicone nelle batterie. Non sono pratico del settore e quindi non ho ben capito bene ma credo sia interessante!

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Pardon, silicio

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Teslas will soon be able to park themselves, steer on the highway

According to Tesla boss Elon Musk, a software update is coming that will enable the Tesla Model S to steer itself on the highway and parallel park autonomously. Announcing the plan on Twitter, Musk said that dealing with low-contrast lane markings has been the final hurdle to getting the feature working.

Highway Autosteer makes the Model S capable of NHTSA's level two automation, still a far cry from a car being able to remotely drive itself from the beginning to end of a destination. While Tesla has made many announcements recently about self-driving features for the Model S that will be unlocked via the version 7 firmware, it remains unclear exactly how such cars will be legal on US roads outside of California (which has issued self-driving cars with permits).

This is no doubt an exciting update for Tesla owners. However, we'd be remiss if we didn't point out that plenty of other cars already come with adaptive cruise control and lane centering—the Audi RS7 we drove last month is one such example. And self-parking cars predate the smartphone age, with Toyota being the first to market in 2003 with self-parking Priuses (in Japan). Still, welcome to the club, Tesla.

arstechnica

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E`solo un prototipo ma...wow!

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In danimarca due programmatori hanno fatto quasi 730km su una P85D con una sola carica

Programmer Drives His Tesla Model S A Record-Breaking 452.8 Miles On A Single Charge | TechCrunch

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Ecco il pilota automatico di Tesla. Ma non puoi (ancora) distrarti

Tramite un aggiornamento OTA, disponibile prima per i modelli USA e successivamente nel resto del mondo, Tesla attiverà in queste ore la tecnologia di guida semi-automatica sulle proprie flagship Model S. Il nome è tutto un programma: Tesla Autopilot, ma in realtà chi già si vede attento alla lettura di un giornare o alla visione di un film mentre la macchina lo porta a destinazione dovrà ricredersi. O quanto meno attendere ancora un po'.

Elon Musk l'ha ripetuto fino allo sfinimento: la modalità Autopilot sfrutterà sì tutti gli infiniti sensori della macchina per offrire - tra l'altro - una risposta automatica alle condizioni del traffico e il cambio di corsia automatico, ma il conducente non potrà staccare le mani dal volante nè distrarsi. La tecnologia è agli albori e un concetto di guida totalmente autonoma verrà raggiunto solo più avanti nel tempo. Una volta attivato il pilota automatico, se il guidatore toglie le mani dal volante verrà avvisato in ogni modo (indicazione sul display, avviso acustico), ed è anche previsto che la macchina - di fronte all'assenza di reazione del conducente - rallenti e si fermi autonomamente.

Musk ha previsto che a livello tecnologico nell'arco di tre anni le automobili ci potranno portare al lavoro in modo del tutto autonomo, ma a livello legislativo una pratica del genere potrebbe richiedere molto di più per essere regolamentata.

[VuOtto]

Guardate un po' qua................La model S è la seconda berlina di lusso venduta in Europa....ne hanno vendute più di 10mila dall'inizio dell'anno!

Articolo via Bimmerfile.

Two years ago, I read this small article in the Mercury News, the local paper in San Jose California. It was about how the Model S accounted for over 15% of new car registrations in the hyper-affluent town of Atherton, CA. Since Atherton is practically next door to Palo Alto, where Tesla is headquartered, this was no big surprise. After all, Tesla is a local darling, and this relatively huge percentage was based on just just 63 purchases (out of 403 new car registrations in the first 8 months of that year). Home town hero combined with a small sample number meant that it was pretty much a local story about how the rich were supporting one of their own.But this new article in Forbes this week shows that the trend is not stopping. For the first 9 months of this year, the Model S has more European sales (10,600) than the BMW 7 series (2,650) and the Audi A8 (4,700), falling just 800 units shy of the leader of the pack, the Mercedes Benz S Class.

But the news for the Germans is even worse. While the first of the Model X has started shipping (admittedly, much, much later than originally planned, thank you Falcon Doors), the electric competitors are all one to three years off. The Audi e-tron Quatro SUV isn’t expected until the 2019 model year. While it is planned to have a slightly longer range than the Model X (310 vs 270 miles), Tesla will have a solid sales start.