Wow -- apparently being a ME and a car nut makes you qualified to assess the viability of electric cars! So would a CS grad who likes to play video games be an expert on assessing the business plan of EA Sports?
Hint: you just *agreed* with someone whose post was based around an error -- that automotive li-ions (at least outside Tesla) have the same properties as cobalt-based laptop cells. It's not even close. They sacrifice bout 50% of their energy density to boost longevity by an order of magnitude.
Let me be the first to call BS on that. Bare minimum, lead-acid batteries don't last that long in normal use, and neither do tires.
The average American spends about as much on maintenance and repairs as they do on gasoline, according to the census. Now, that doesn't break down accident repairs from failure repairs, but still, you get the picture.
Right. It's not like modern power electronics have let us shrink supercar motors to the size of a watermelon, or like battery energy density has 4.5xed and power density 10xed in the past 21 years, or anything like that.
No, in your world, a Baker Electric is the same as a Tesla Roadster.
The Prius's pack started out at 6k and the same doomsday prophets shouted that theyr value would collapse come resale time. Fast forward to today. The battery pack is now just over $2k and the Prius holds value better than all but a few cars.
Thanks for posting those pictures because that illustrates the point perfectly. A compressor blade's weight is on the order of ounces and operates at about 10,000 RPM. Even a *small* flywheel system like Flybrid's has a flywheel weighing over 10lbs that goes at up to 60,000 RPM.
Get the point yet?
You really have never heard of the Ford Pinto?
Hyperbole aside, the Ford Pinto did not explode. An explosion is an effectively instantaneous release of energy. The Pinto merely leaked gasoline which could catch fire. It takes about 10 minutes to burn off a car's gas tank worth of gasoline. It takes a small fraction of a second to unleash all of the energy in a flywheel.
Notice the difference?
Do you really think the lawyers would have allowed automobile / airplanes to be created if they were invented today?
Yes. See above.
There's a huge difference between a slow energy release and a rapid energy release.
As for batteries, the public has the impression that batteries are safe and environmentally friendly. This may change over time when the energy density of batteries starts to compete with fossil fuels, and more laptop batteries start catching fire.
Ah, more myths. The primary types of batteries used in modern production EVs -- lithium iron phosphate and the various lithium manganates -- *ARE* safe and environmentally friendly. They're nontoxic -- you literally can throw them in the trash in most municipalities after discharging. They do not "catch fire". The phosphates will generally smoke if you cut them open and provide a heat source. The manganates won't even do that. And they can tolerate an obscene amount of abuse -- things like high rate charge/discharge cycles to 0% capacity back up to 100% in sub-zero weather, and the like. They don't have the energy density of the cobalt-based cells like you find in laptops, but for automotive applications, safety and durability is preferred. Only Tesla (and their partners) are using the cobalt-based "laptop" cells (18650 format), and even in their case, they isolate each cell into its own individual can to prevent failure propagation. And it absolutely works.
Just because you scoff at an argument does not mean you actually answered the argument. As for women flying in planes, I don't know what that has to do with the argument. There are plenty of women aviators.
Are, not were. Early in aviation's history, you were considered a daredevil if you were willing to fly a plane. The risk was met by a similarly risk-prone crowd. It was NOT mass market.
There was no time in human history where the mass market didn't care about their safety.
"Traces"? What is that supposed to mean? How does quantum tunnelling affect batteries in general, or even specifically li-ion?
The primary (but not only) limitation to li-ion batteries are the intercalation density of the electrodes, which has nothing to do with quantum tunnelling. Hell, it's even possible to use air as one electrode (effectively infinite density) and lithium metal as the other (orders of magnitude more density than intercalated graphite). In that case, it's all about engineering to prevent dendrites from destroying the membrane, preventing membrane poisoning, anode poisoning, etc.
Heck, quantum effects are actually *key* to some battery proposals. Look up "digital quantum battery", for example. It's actually a nano-capacitor array that relies on the fact that current flows in quanta to prevent dielectric breakdown until at high voltages.
The "catastrophic" failure mode of an internal combustion engine is a blown cylinder. Not all that catastrophic. Same with a jet engine compressor losing a blade. Now, if you're talking about simply "moving" or "flying", that would involve multiple separate systems failing for it to be catastrophic. For example, on a car, you need the brakes to fail as well. On an airplane, you need multiple engines to fail or some other problem. Etc.
Beyond the increased risk, flywheels are well behind batteries in most regards, and will likely continue to be so.
Well, alkalines don't last long in a digital camera because their capacity is far smaller on big loads.
It's about inferior voltage discharge curves.
On small loads, they'll destroy any NiMH battery.
No longer true; today's NiMHs now boast about the same mAh as alkaline.
Is it not possible to shove a small voltage regulator and a li-ion battery into a AA-sized container such that it produces 1.5v of output voltage?
It's not really easy. The simple approach is a linear regulator, which basically means that you pile in resistors to lower the voltage. But that's obviously really wasteful and means lots of heat. Switched mode and magnetic regulators are too big and expensive for something like a AA cell.
NiMH AAs weren't available immediately. When they did become available, they were pretty pathetic, a far cry from today's NiMH AAs.
Li-ion doesn't scale down that small very well because of the required charge management hardware and because the nominal voltage is too low for a single cell but too high if you put two in parallel. As a consequence, things that want to use li-ions typically use li-ion packs, not AAs, and run at different voltages. However, today we finally have at least li-ion primary cells in AA form factor that work in some devices which are half the weight of NiMHs yet deliver ~3,000 mAh.
Dare we even compare today's NiMH or li-ion AAs all to alkalines? Try putting alkalines in a digital camera that takes AAs and see how long it lasts;)
The closest thing to a secondary-cell li-ion AA you'll usually find is the ever-common 18650 cell. Break open your typical li-ion battery pack for a laptop and you'll probably find them. They look kind of like AAs, but they're not -- they're a nominal 3.7V, not 4.5V.
What articles were you reading that said a battery tech would go from "in the lab" to "on the market" in 18 months? 5 years or so is more typical. And 500% battery improvement tech announcements are rare. There are a couple out there, like li-air, but not many. And many people confuse significant improvements on one part of a battery (say, the anode or cathode) with improvements on the cell as a whole.
Li-ion batteries have advanced about 40% since 2005.
There's a serious problem with the announcements making the news but the commercialization coming in under the radar. Remember back in 2007 when Slashdot covered that silicon nanowires had been determined to be an excellent anode for li-ion batteries? The reporting was crap, mind you -- they confused an anode density improvement "up to 10x" with being a whole battery improvement (even a 10x anode improvement would be an under 2x battery improvement if not paired with an equivalent cathode improvement, mind you). The researcher was looking to be "forming a company", but first they would have to deal with "cycle life" problems. The first batteries of this type were to hit the market as early as 5 years.
It's only 3 years later and it's already started. Mind you, these first versions are much more limited -- they start out. But as the tech is refined, they will continue to advance, just like the old graphite anodes did. Early li-ion cells really sucked compared to what we have today. Silicon will go through the same process.
You see the same thing with cathodes. And other anode materials. And separators, and electrolytes, and casings. And all in all, the tech marches on. But consumers don't even notice it because their devices just keep shrinking the batteries and consuming more power. The battery improvement isn't Moore's impressive doubling-every-1.5-years. But it's just as relentless.
Wrong. They're specific to *cobalt cathode* li-ion cells. Not any cells that have lithium in them. There are freaking rocket boosters made out of lithium-aluminum, exposed to high temperature flames, and they don't burn. Just because something contains lithium doesn't make it flammable. Just like how because our bodies contain sodium doesn't mean that we explode when we get hit by water.
The only companies pursuing li-ion cells with cobalt cathodes are Tesla Motors and their partners. The others are all using phosphates and manganates. Neither the phosphates nor the manganates pose a fire hazard. One, they take *far* more abuse to cause a problem, and two, all the phosphates generally do upon rupture is smoke. The manganates don't generally even do that.
Furthermore, even the Tesla approach addresses the problem. They do use the cells with the runaway thermal risk, but they isolate each cell in its own can specifically designed to contain any failure and prevent propagation. There have already been a number of Tesla Roadster wrecks, some very signicant (the battery pack is at the back). Not a single battery fire or other such problem.
In the last year or so there's been a new battery research story every month promising longer lasting batteries that are smaller and usually cheaper. Yet the most advanced you can buy are still just play Lithium Polymer batteries which seem to power my Android phone for about 15 minutes.
The late '80s just called -- they want you to remember what their cell phone batteries looked like.
The problem is that batteries aren't advancing. They are, at about 8% per year. It's that electronics manufacturers aren't primarily using the advances so much for longer runtime, but for smaller size and higher power consumption.
Sounds like you're perpetuating the "batteries haven't improved" myth. Batteries have advanced at about 8% per year for the past two decades, and show no signs of slowing down (actually, just the opposite). The problem is that most people experience batteries through electronics, and electronics' demands on batteries have grown nearly correspondingly.
Back in 1989, the best top-of-the-line rechargeable cells were the brand new NiMHs, with an energy density of about 45Wh/kg. Today, the best on the market are 220Wh/kg li-ions (or are they up to 240 by now?) And just watch as the new silicon-anode cells start rolling out (it's already started); they'll end up blowing the old graphite cells away.
If the rate continues, in another 20 years, a 215-mile EV today will be a 1000 mile EV. In 30 years, a 100-mile EV today will be a 1000 mile EV. Now, one can say, "Sure, that's the trend that's existed for the past 20 years", but it won't continue. Well, to be honest, as mentioned, the rate of advancement only seems to be increasing. There are literally dozens of next gen techs already being worked on that could hit the 15-20 year target but should only take ~5-10 years to commercialize. Will all of them work out? No. Will most of them fail to play out? Yes. But will all of them fail? There's virtually no chance of that happening. And already we have some techs in the lab that could hit targets in that 20-30 year timeframe -- li-air, digital quantum, etc. In fact, there was a huge advancement announced in Li-air just a couple weeks ago -- they got the efficiency up to ~85%, and think they can get it even higher. And they think it'll improve the lifespan, too (efficiency and lifespan were the two biggest problems with li-air).
No. We have no carbon nanotube-based materials that could make a flywheel anywhere close to batteries in terms of energy density. Individual tubes do not a similar bulk material make. Plus, flywheels have catastrophic failure modes, don't scale down well, and all sorts of other problems.
They have their uses, but if you compare what's on the market today to what's on the market today, and what's forecast versus what's forecast, it's really hard to make the case for flywheels. Heck, has anyone even broken 40Wh/kg yet? Flybrid is only at 22Wh/kg.
Some fishing has recovered at Valdez; others haven't. There is no exposed oil, but there is buried oil. Burial slows degradation.
A good lesson can come from natural seeps. Life isn't adapted to intense releases of oil concentrated in a given location. It is adapted to oil coming into an ecosystem in small quantities. Hence, the oil will be devastating to the Mississippi River Delta, and to a lesser extent, regions adjacent (if winds and currents hit it just right, it could cause some problems in the Keys as well). But at the same time, the talk of heavy oil slicks covering the US east coast, or even more extreme, turning all of the world's oceans to poison (yes, I've heard people make that claim) are pure hyperbole.
If the Mississippi River Delta responds in the same way that the BOC responded to Ixtoc 1, it could be largely back to normal in two years. But there are definitely differences this time (namely, the depth, the extensive use of dispersants, and the low-oxygen waters of the delta). How that will change the picture, who knows. I suspect they'll slow the recovery.
But most of the cost of solid rocket motors is the fuel,
The standard rule of rocketry is if your fuel costs are a significant percent of your total costs, you're doing something *right*. It's generally not even close.
Slashdot Mirror
Oh, and this is from another site, but is still my favorite. ;)
Geeky tattoos aren't even rare. Check out this site. Some of them are really clever/impressive.
There's also the site "geekytattoos.com", but it seems more focused on gaming and geek culture.
They're not AAs -- They're 18650s.
We can't even standardize laptop batteries and by all standards they're a *much* easier target.
Think's problem is the randomness of low volumes.
Wow -- apparently being a ME and a car nut makes you qualified to assess the viability of electric cars! So would a CS grad who likes to play video games be an expert on assessing the business plan of EA Sports?
Hint: you just *agreed* with someone whose post was based around an error -- that automotive li-ions (at least outside Tesla) have the same properties as cobalt-based laptop cells. It's not even close. They sacrifice bout 50% of their energy density to boost longevity by an order of magnitude.
Let me be the first to call BS on that. Bare minimum, lead-acid batteries don't last that long in normal use, and neither do tires.
The average American spends about as much on maintenance and repairs as they do on gasoline, according to the census. Now, that doesn't break down accident repairs from failure repairs, but still, you get the picture.
Right. It's not like modern power electronics have let us shrink supercar motors to the size of a watermelon, or like battery energy density has 4.5xed and power density 10xed in the past 21 years, or anything like that.
No, in your world, a Baker Electric is the same as a Tesla Roadster.
How often do you run your gastank down to 0%?
The Prius's pack started out at 6k and the same doomsday prophets shouted that theyr value would collapse come resale time. Fast forward to today. The battery pack is now just over $2k and the Prius holds value better than all but a few cars.
Thanks for posting those pictures because that illustrates the point perfectly. A compressor blade's weight is on the order of ounces and operates at about 10,000 RPM. Even a *small* flywheel system like Flybrid's has a flywheel weighing over 10lbs that goes at up to 60,000 RPM.
Get the point yet?
You really have never heard of the Ford Pinto?
Hyperbole aside, the Ford Pinto did not explode. An explosion is an effectively instantaneous release of energy. The Pinto merely leaked gasoline which could catch fire. It takes about 10 minutes to burn off a car's gas tank worth of gasoline. It takes a small fraction of a second to unleash all of the energy in a flywheel.
Notice the difference?
Do you really think the lawyers would have allowed automobile / airplanes to be created if they were invented today?
Yes. See above.
There's a huge difference between a slow energy release and a rapid energy release.
As for batteries, the public has the impression that batteries are safe and environmentally friendly. This may change over time when the energy density of batteries starts to compete with fossil fuels, and more laptop batteries start catching fire.
Ah, more myths. The primary types of batteries used in modern production EVs -- lithium iron phosphate and the various lithium manganates -- *ARE* safe and environmentally friendly. They're nontoxic -- you literally can throw them in the trash in most municipalities after discharging. They do not "catch fire". The phosphates will generally smoke if you cut them open and provide a heat source. The manganates won't even do that. And they can tolerate an obscene amount of abuse -- things like high rate charge/discharge cycles to 0% capacity back up to 100% in sub-zero weather, and the like. They don't have the energy density of the cobalt-based cells like you find in laptops, but for automotive applications, safety and durability is preferred. Only Tesla (and their partners) are using the cobalt-based "laptop" cells (18650 format), and even in their case, they isolate each cell into its own individual can to prevent failure propagation. And it absolutely works.
Just because you scoff at an argument does not mean you actually answered the argument. As for women flying in planes, I don't know what that has to do with the argument. There are plenty of women aviators.
Are, not were. Early in aviation's history, you were considered a daredevil if you were willing to fly a plane. The risk was met by a similarly risk-prone crowd. It was NOT mass market.
There was no time in human history where the mass market didn't care about their safety.
Compressor blades / turbines on jets can fly off shredding any one in it's path.
Only in Hollywood. They're actually small and low mass.
If the Engine breaks, the place can crash killing people.
The loss of one engine does not a crash make.
The idea of powering something with a burnable fluid dangersous fluid would not be acceptable today.
Failure of gasoline: Fire.
Failure of a flywheel: Explosion.
You really don't notice the difference?
Planes and cars were engineered before during a time when people were willing to live with a little danger
Ah, the old "golden age" myth. The good old days when women weren't even supposed to ride in planes because of the danger.
Are you saying that engineering conrtrolls could not be put in place to mitigate the danger of a flywheel rapidly disassembling itself?
What part of "virtually instant energy release" are you planning to work around without making the Wh/kg abyssmal?
Ha, that thing is great! Thanks for the link.
"Traces"? What is that supposed to mean?
How does quantum tunnelling affect batteries in general, or even specifically li-ion?
The primary (but not only) limitation to li-ion batteries are the intercalation density of the electrodes, which has nothing to do with quantum tunnelling. Hell, it's even possible to use air as one electrode (effectively infinite density) and lithium metal as the other (orders of magnitude more density than intercalated graphite). In that case, it's all about engineering to prevent dendrites from destroying the membrane, preventing membrane poisoning, anode poisoning, etc.
Heck, quantum effects are actually *key* to some battery proposals. Look up "digital quantum battery", for example. It's actually a nano-capacitor array that relies on the fact that current flows in quanta to prevent dielectric breakdown until at high voltages.
The "catastrophic" failure mode of an internal combustion engine is a blown cylinder. Not all that catastrophic. Same with a jet engine compressor losing a blade. Now, if you're talking about simply "moving" or "flying", that would involve multiple separate systems failing for it to be catastrophic. For example, on a car, you need the brakes to fail as well. On an airplane, you need multiple engines to fail or some other problem. Etc.
Beyond the increased risk, flywheels are well behind batteries in most regards, and will likely continue to be so.
Well, alkalines don't last long in a digital camera because their capacity is far smaller on big loads.
It's about inferior voltage discharge curves.
On small loads, they'll destroy any NiMH battery.
No longer true; today's NiMHs now boast about the same mAh as alkaline.
Is it not possible to shove a small voltage regulator and a li-ion battery into a AA-sized container such that it produces 1.5v of output voltage?
It's not really easy. The simple approach is a linear regulator, which basically means that you pile in resistors to lower the voltage. But that's obviously really wasteful and means lots of heat. Switched mode and magnetic regulators are too big and expensive for something like a AA cell.
NiMH AAs weren't available immediately. When they did become available, they were pretty pathetic, a far cry from today's NiMH AAs.
Li-ion doesn't scale down that small very well because of the required charge management hardware and because the nominal voltage is too low for a single cell but too high if you put two in parallel. As a consequence, things that want to use li-ions typically use li-ion packs, not AAs, and run at different voltages. However, today we finally have at least li-ion primary cells in AA form factor that work in some devices which are half the weight of NiMHs yet deliver ~3,000 mAh.
Dare we even compare today's NiMH or li-ion AAs all to alkalines? Try putting alkalines in a digital camera that takes AAs and see how long it lasts ;)
The closest thing to a secondary-cell li-ion AA you'll usually find is the ever-common 18650 cell. Break open your typical li-ion battery pack for a laptop and you'll probably find them. They look kind of like AAs, but they're not -- they're a nominal 3.7V, not 4.5V.
What articles were you reading that said a battery tech would go from "in the lab" to "on the market" in 18 months? 5 years or so is more typical. And 500% battery improvement tech announcements are rare. There are a couple out there, like li-air, but not many. And many people confuse significant improvements on one part of a battery (say, the anode or cathode) with improvements on the cell as a whole.
Li-ion batteries have advanced about 40% since 2005.
There's a serious problem with the announcements making the news but the commercialization coming in under the radar. Remember back in 2007 when Slashdot covered that silicon nanowires had been determined to be an excellent anode for li-ion batteries? The reporting was crap, mind you -- they confused an anode density improvement "up to 10x" with being a whole battery improvement (even a 10x anode improvement would be an under 2x battery improvement if not paired with an equivalent cathode improvement, mind you). The researcher was looking to be "forming a company", but first they would have to deal with "cycle life" problems. The first batteries of this type were to hit the market as early as 5 years.
It's only 3 years later and it's already started. Mind you, these first versions are much more limited -- they start out. But as the tech is refined, they will continue to advance, just like the old graphite anodes did. Early li-ion cells really sucked compared to what we have today. Silicon will go through the same process.
You see the same thing with cathodes. And other anode materials. And separators, and electrolytes, and casings. And all in all, the tech marches on. But consumers don't even notice it because their devices just keep shrinking the batteries and consuming more power. The battery improvement isn't Moore's impressive doubling-every-1.5-years. But it's just as relentless.
Wrong. They're specific to *cobalt cathode* li-ion cells. Not any cells that have lithium in them. There are freaking rocket boosters made out of lithium-aluminum, exposed to high temperature flames, and they don't burn. Just because something contains lithium doesn't make it flammable. Just like how because our bodies contain sodium doesn't mean that we explode when we get hit by water.
The only companies pursuing li-ion cells with cobalt cathodes are Tesla Motors and their partners. The others are all using phosphates and manganates. Neither the phosphates nor the manganates pose a fire hazard. One, they take *far* more abuse to cause a problem, and two, all the phosphates generally do upon rupture is smoke. The manganates don't generally even do that.
Furthermore, even the Tesla approach addresses the problem. They do use the cells with the runaway thermal risk, but they isolate each cell in its own can specifically designed to contain any failure and prevent propagation. There have already been a number of Tesla Roadster wrecks, some very signicant (the battery pack is at the back). Not a single battery fire or other such problem.
Describe the physics of the limit you refer to, for our enlightenment.
In the last year or so there's been a new battery research story every month promising longer lasting batteries that are smaller and usually cheaper. Yet the most advanced you can buy are still just play Lithium Polymer batteries which seem to power my Android phone for about 15 minutes.
The late '80s just called -- they want you to remember what their cell phone batteries looked like.
The problem is that batteries aren't advancing. They are, at about 8% per year. It's that electronics manufacturers aren't primarily using the advances so much for longer runtime, but for smaller size and higher power consumption.
Sounds like you're perpetuating the "batteries haven't improved" myth. Batteries have advanced at about 8% per year for the past two decades, and show no signs of slowing down (actually, just the opposite). The problem is that most people experience batteries through electronics, and electronics' demands on batteries have grown nearly correspondingly.
Back in 1989, the best top-of-the-line rechargeable cells were the brand new NiMHs, with an energy density of about 45Wh/kg. Today, the best on the market are 220Wh/kg li-ions (or are they up to 240 by now?) And just watch as the new silicon-anode cells start rolling out (it's already started); they'll end up blowing the old graphite cells away.
If the rate continues, in another 20 years, a 215-mile EV today will be a 1000 mile EV. In 30 years, a 100-mile EV today will be a 1000 mile EV. Now, one can say, "Sure, that's the trend that's existed for the past 20 years", but it won't continue. Well, to be honest, as mentioned, the rate of advancement only seems to be increasing. There are literally dozens of next gen techs already being worked on that could hit the 15-20 year target but should only take ~5-10 years to commercialize. Will all of them work out? No. Will most of them fail to play out? Yes. But will all of them fail? There's virtually no chance of that happening. And already we have some techs in the lab that could hit targets in that 20-30 year timeframe -- li-air, digital quantum, etc. In fact, there was a huge advancement announced in Li-air just a couple weeks ago -- they got the efficiency up to ~85%, and think they can get it even higher. And they think it'll improve the lifespan, too (efficiency and lifespan were the two biggest problems with li-air).
No. We have no carbon nanotube-based materials that could make a flywheel anywhere close to batteries in terms of energy density. Individual tubes do not a similar bulk material make. Plus, flywheels have catastrophic failure modes, don't scale down well, and all sorts of other problems.
They have their uses, but if you compare what's on the market today to what's on the market today, and what's forecast versus what's forecast, it's really hard to make the case for flywheels. Heck, has anyone even broken 40Wh/kg yet? Flybrid is only at 22Wh/kg.
The sales pitch for this laser is way overhyped. It's only a 1W laser. Want to see a 1W laser burn things? Here. Underwhelming, no?
I can just imagine that in a defensive situation -- "Hold your hand still and steady while I try to light it on fire. That'll teach you!"
The risk from this thing is blinding.
The heavy fraction does stick around.
Some fishing has recovered at Valdez; others haven't. There is no exposed oil, but there is buried oil. Burial slows degradation.
A good lesson can come from natural seeps. Life isn't adapted to intense releases of oil concentrated in a given location. It is adapted to oil coming into an ecosystem in small quantities. Hence, the oil will be devastating to the Mississippi River Delta, and to a lesser extent, regions adjacent (if winds and currents hit it just right, it could cause some problems in the Keys as well). But at the same time, the talk of heavy oil slicks covering the US east coast, or even more extreme, turning all of the world's oceans to poison (yes, I've heard people make that claim) are pure hyperbole.
If the Mississippi River Delta responds in the same way that the BOC responded to Ixtoc 1, it could be largely back to normal in two years. But there are definitely differences this time (namely, the depth, the extensive use of dispersants, and the low-oxygen waters of the delta). How that will change the picture, who knows. I suspect they'll slow the recovery.
But most of the cost of solid rocket motors is the fuel,
The standard rule of rocketry is if your fuel costs are a significant percent of your total costs, you're doing something *right*. It's generally not even close.