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You're welcome! Unfortunately, I'm mostly on the supply side of the battery equation, consuming those few PDFs that are smuggled out. The most surprising thin

You're welcome! Unfortunately, I'm mostly on the supply side of the battery equation, consuming those few PDFs that are smuggled out. The most surprising thing, to me, is that battery tech moves in a zig-zag shape. The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2014. A lot of really expensive things that need that battery are now running off of old stock, which will of course eventually run out. The best comparable battery made in 2016 has less than half its performance. Another example of this is energy density. For practical purposes, the best density you could reasonably buy was fixed around 90 Wh/kg for a while (until about 1997), then suddenly jumped to ~180 Wh/kg (~2002), then went in 2006 to ~260 Wh/kg... and sat there, where it has sat for eleven years now with practically zero improvement. [0] If I teleported to today from 2006 I'd expect to have some fantastic 400 Wh/kg batteries that would enable all kinds of new technologies... but nope, the best energy density you can get is literally the same as it was eleven years ago. Worth noting that since 2006 discharge rates of high capacity batteries have gone up, to be perfectly fair. Still though, energy density remains stagnant. [0] Looking at graphs on Google Images will give you the wrong idea. They typically show the best batteries that year, not necessarily ones you can actually buy, and the numbers are often pulled out of thin air. This graph [1] is the least worst, but that's not saying much. [1] http://media.greenmonk.net/greenmonk/files/2015/11/Li-IonDensity.jpg http://media.greenmonk.net/greenmonk/files/2015/11/Li-IonDen...

deepGem 10y ago
Thanks for posting this. A totally unrelated question, if you don't mind answering. Given all this, do you believe that Tesla is changing the battery market dynamics with their GigaFactory. Musk has claimed that their plan is to increase the energy density, but hasn't given out any specifics.
- nolok 10y ago
  Not parent, but whatever their plan is, energy density is limited by the technology, not the will. It's not like Panasonic could manufacture battery with twice the energy density if they wanted to, with some tech they're hiding in their back pocket. As for the "gigafactory", it's Tesla trying to get into that closed market, like parent said there are only a few big players and it's not very welcoming to new ones, Tesla's plan is to be so big that they can have a big supply to sell in bulk AND to also be (together with solar city I guess) one of their first big scale customer.
  - ryao 10y ago
    I think you mean the electro-chemical cell. Batteries are just bundles of electrochemical cells (and 1 cell can be a bundle). I am far from an expert on this, but tighter packing of electrochemical cells could improve density.
    - owenversteeg 10y ago
      > Batteries are just bundles of electrochemical cells (and 1 cell can be a bundle) Correct. The problem with packing cells tighter is heat production: a ridiculous amount of heat is released and the individual cells can get up to 80 degrees C / 176 F. (80C is not a "doomsday scenario"; most cells are rated to sit there running at 80C just fine.) When they're all next to each other, tightly packed in with no place for heat to go, you're screwed. The other reason is that volumetric density is usually not what people optimize for; gravimetric density is more useful most of the time, and in that case you don't really have any reason to use tighter packing.
      - ufo 10y ago
        Why is gravimetric density more important than volumetric density? That sounds counter intuitive to me.
        owenversteeg 10y ago
        Places where gravimetric density is more important: - Electric vehicles - Aircraft - R/C - Anything that goes into space - Large scale energy storage (good energy density typically = less lithium used) - Generally: anything that moves Places where both are equally important: - Consumer electronics (you don't want an ultra slim 2lb phone, or a ultra thick featherweight phone) Places where volumetric density is more important: - Batteries in smartcards - Some medical devices - Certain flashlights, IoT devices You'll notice that there are a lot more things where people care more about gravimetric density. Also, the best Li-Ion cells for volumetric density that you can buy are rather inconvenient shapes; a favorite is the 18650, an 18mm diameter by 65mm long cylinder. Yes, the best 18650 technically has much better volumetric density than the iPhone batteries. But if you swapped the iPhone battery with an 18650 you'd have a hilarious looking semi-cylinder protruding from the back.
- owenversteeg 10y ago
  You're welcome! TL;DR They're changing the market dynamics but their cells are boring aside from being cheap and will probably stay that way for a while. So first of all, yes they will change the market dynamics; anyone selling as many batteries as they (plan to) do will change the market. Secondly, the gigafactory's cells aren't that interesting (right now) aside from being cheap. The cell lifetime is atrocious, between half to a quarter that of the market standard. The energy density is not great, around 220 Wh/kg for the best cells and 190 Wh/kg for the worse ones; this is slightly better than the cutting edge fifteen years ago. The power density they claim is unacceptable given what it does to the cell life. And since the cells are larger, they require new cooling systems. Musk is a fascinating guy, for sure, but he's just as human as the rest of us. An absolutely gargantuan amount of cash has been piled into battery research in the last 11 years, with zero appreciable gains in energy density. If the Gigafactory ever produces a high energy density cell, it'll almost certainly be because their partner Panasonic (which is one of the few battery companies on the cutting edge) made a breakthrough and licensed it to them. Finally, the battery market is a very strange thing: many makers of the 'good' cells won't sell to anyone except a few specific clients. These clients buy the cells (on paper) to make things like power tools or electric vehicles or battery packs. However, these clients vastly over-buy, and then sell off their excess stock to resellers. Anytime you buy a powerbank, or a loose 18650 cell for an e-cigarette, or a battery pack for an ebike, you're almost certainly going to end up with cells that have been resold at least twice. As such, the easiest way that Tesla could absolutely revolutionize the industry is by simply saying "hey, if your needed capacity is more than $25K per year, give us a call" and selling directly to businesses. They could even put up a quote on their website à la SpaceX. Unfortunately, I've got a feeling that if Tesla did that their partners at Panasonic would make heads roll, but you never know.
  - Keyframe 10y ago
    That's interesting, to say the least. You can't just call Saft and order some cells then? They won't sell them to you?
    - owenversteeg 10y ago
      I'm not sure about Saft in particular; with how ridiculously bad their tech is I'm convinced they are a French government jobs program, and nobody I know has ever voluntarily used their cells (except years ago for non-rechargeable.) For reference, their highest energy density Li-Ion cell is 169 Wh/kg. I'm not sure how they managed to be that bad; I just literally taped a rock (14g) to the cheapest battery in my apartment (45.8g, the $2.49 NCR18650PF) and the combined energy density of my new Rock-Lithium-Ion Battery is 170 Wh/kg, better than that of Saft's highest energy density rechargeable cell. But yes; if you want newer battery technology direct from the manufacturer, you'll probably be flat-out ignored even if you're inquiring at a medium-large scale. The way to do it is to hunt around for semi-reputable resellers, who will usually give you what you want at an acceptable price.
yosyp 10y ago
The stagnation of Li-ion batteries can be attributed to industry approaching the theoretical maximum energy density. So instead of optimizing the remaining 25%-30% capacity, focus shifted to Li-air or Li-S research. Li-S in particular can reach up to 2600 Wh/kg theoretical energy density, or 10x of current state of the art. Maybe you can shine some light on this, why do the search trends [1] for lithium sulfur appear so cyclic? I'm not aware of any uses in industry, or any major conferences/press cycles around Li-S. [1] https://www.google.com/trends/explore?date=all&q=lithium%20sulfur https://www.google.com/trends/explore?date=all&q=lithium%20s...
ggreer 10y ago
> The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2014. A lot of really expensive things that need that battery are now running off of old stock, which will of course eventually run out. Don't lithium ion batteries degrade over time? If that's the case, then how is this 3-5 year old stock still the best available?
jdietrich 10y ago
>The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2014. VTC5?
- owenversteeg 10y ago
  Haha, glad someone tried to guess! But nope, there are several cells that beat the VTC5. Two that come to mind immediately (that beat the VTC5) are the 25R and the VTC6, both of which run cooler and have a higher capacity than the VTC5. You probably haven't heard of the specific battery I'm thinking of unless you've worked a decent amount with batteries, though; it's not terribly popular with hobbyists (part of that, of course, is that it can be hard to get.)
bigger_cheese 10y ago
In 2010 I experimented with Graphene as the Anode of a Li Ion battery. The results at the time were pretty promising but we (the lab at my uni) were synthesizing all of the material ourselves - there was no graphene supply chain and it was very expensive. We always talked about specific capacity (q, charge per unit weight) so all the numbers I'm quoting will be in that - you can multiply by voltage to convert. We were obtaining specific capacities around 500 mAh/g. Vs q= ~370 mAh/g max for graphite anode. I recall based on theoretical modelling ~660 MAh/g could have been achievable with graphene. This pales in comparison to tin or cobalt anodes, which back in 2010 had q = 990 or so. We were not really optimizing for energy density. Rather with carbon based anodes we would see much better cyclical performance due to the lower volume expansion during Li intercalation. So you would be able to get much more charge/discharge cycles without the loss of performance you'd typically see in a higher energy density metal based anode. I work in a different industry now and have not followed battery development closely. I'd speculate a similar thing has happened in the "real world" the energy density may not have improved significantly since 2006 but the cycle life is probably better.
- logicallee 10y ago
  multiply with what voltage? sorry I'm being dumb - can you say the number?

deepGem 10y ago

Thanks for posting this. A totally unrelated question, if you don't mind answering. Given all this, do you believe that Tesla is changing the battery market dynamics with their GigaFactory. Musk has claimed that their plan is to increase the energy density, but hasn't given out any specifics.

nolok 10y ago
Not parent, but whatever their plan is, energy density is limited by the technology, not the will. It's not like Panasonic could manufacture battery with twice the energy density if they wanted to, with some tech they're hiding in their back pocket. As for the "gigafactory", it's Tesla trying to get into that closed market, like parent said there are only a few big players and it's not very welcoming to new ones, Tesla's plan is to be so big that they can have a big supply to sell in bulk AND to also be (together with solar city I guess) one of their first big scale customer.
- ryao 10y ago
  I think you mean the electro-chemical cell. Batteries are just bundles of electrochemical cells (and 1 cell can be a bundle). I am far from an expert on this, but tighter packing of electrochemical cells could improve density.
  - owenversteeg 10y ago
    > Batteries are just bundles of electrochemical cells (and 1 cell can be a bundle) Correct. The problem with packing cells tighter is heat production: a ridiculous amount of heat is released and the individual cells can get up to 80 degrees C / 176 F. (80C is not a "doomsday scenario"; most cells are rated to sit there running at 80C just fine.) When they're all next to each other, tightly packed in with no place for heat to go, you're screwed. The other reason is that volumetric density is usually not what people optimize for; gravimetric density is more useful most of the time, and in that case you don't really have any reason to use tighter packing.
    - ufo 10y ago
      Why is gravimetric density more important than volumetric density? That sounds counter intuitive to me.
      - owenversteeg 10y ago
        Places where gravimetric density is more important: - Electric vehicles - Aircraft - R/C - Anything that goes into space - Large scale energy storage (good energy density typically = less lithium used) - Generally: anything that moves Places where both are equally important: - Consumer electronics (you don't want an ultra slim 2lb phone, or a ultra thick featherweight phone) Places where volumetric density is more important: - Batteries in smartcards - Some medical devices - Certain flashlights, IoT devices You'll notice that there are a lot more things where people care more about gravimetric density. Also, the best Li-Ion cells for volumetric density that you can buy are rather inconvenient shapes; a favorite is the 18650, an 18mm diameter by 65mm long cylinder. Yes, the best 18650 technically has much better volumetric density than the iPhone batteries. But if you swapped the iPhone battery with an 18650 you'd have a hilarious looking semi-cylinder protruding from the back.
owenversteeg 10y ago
You're welcome! TL;DR They're changing the market dynamics but their cells are boring aside from being cheap and will probably stay that way for a while. So first of all, yes they will change the market dynamics; anyone selling as many batteries as they (plan to) do will change the market. Secondly, the gigafactory's cells aren't that interesting (right now) aside from being cheap. The cell lifetime is atrocious, between half to a quarter that of the market standard. The energy density is not great, around 220 Wh/kg for the best cells and 190 Wh/kg for the worse ones; this is slightly better than the cutting edge fifteen years ago. The power density they claim is unacceptable given what it does to the cell life. And since the cells are larger, they require new cooling systems. Musk is a fascinating guy, for sure, but he's just as human as the rest of us. An absolutely gargantuan amount of cash has been piled into battery research in the last 11 years, with zero appreciable gains in energy density. If the Gigafactory ever produces a high energy density cell, it'll almost certainly be because their partner Panasonic (which is one of the few battery companies on the cutting edge) made a breakthrough and licensed it to them. Finally, the battery market is a very strange thing: many makers of the 'good' cells won't sell to anyone except a few specific clients. These clients buy the cells (on paper) to make things like power tools or electric vehicles or battery packs. However, these clients vastly over-buy, and then sell off their excess stock to resellers. Anytime you buy a powerbank, or a loose 18650 cell for an e-cigarette, or a battery pack for an ebike, you're almost certainly going to end up with cells that have been resold at least twice. As such, the easiest way that Tesla could absolutely revolutionize the industry is by simply saying "hey, if your needed capacity is more than $25K per year, give us a call" and selling directly to businesses. They could even put up a quote on their website à la SpaceX. Unfortunately, I've got a feeling that if Tesla did that their partners at Panasonic would make heads roll, but you never know.
- Keyframe 10y ago
  That's interesting, to say the least. You can't just call Saft and order some cells then? They won't sell them to you?
  - owenversteeg 10y ago
    I'm not sure about Saft in particular; with how ridiculously bad their tech is I'm convinced they are a French government jobs program, and nobody I know has ever voluntarily used their cells (except years ago for non-rechargeable.) For reference, their highest energy density Li-Ion cell is 169 Wh/kg. I'm not sure how they managed to be that bad; I just literally taped a rock (14g) to the cheapest battery in my apartment (45.8g, the $2.49 NCR18650PF) and the combined energy density of my new Rock-Lithium-Ion Battery is 170 Wh/kg, better than that of Saft's highest energy density rechargeable cell. But yes; if you want newer battery technology direct from the manufacturer, you'll probably be flat-out ignored even if you're inquiring at a medium-large scale. The way to do it is to hunt around for semi-reputable resellers, who will usually give you what you want at an acceptable price.

yosyp 10y ago

The stagnation of Li-ion batteries can be attributed to industry approaching the theoretical maximum energy density. So instead of optimizing the remaining 25%-30% capacity, focus shifted to Li-air or Li-S research. Li-S in particular can reach up to 2600 Wh/kg theoretical energy density, or 10x of current state of the art. Maybe you can shine some light on this, why do the search trends [1] for lithium sulfur appear so cyclic? I'm not aware of any uses in industry, or any major conferences/press cycles around Li-S. [1] https://www.google.com/trends/explore?date=all&q=lithium%20sulfur https://www.google.com/trends/explore?date=all&q=lithium%20s...

ggreer 10y ago

> The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2014. A lot of really expensive things that need that battery are now running off of old stock, which will of course eventually run out. Don't lithium ion batteries degrade over time? If that's the case, then how is this 3-5 year old stock still the best available?

jdietrich 10y ago

>The best battery that money can buy, for two of pretty much the most important applications (can't elaborate further, sorry) was only made from ~2012 until ~2014. VTC5?

owenversteeg 10y ago
Haha, glad someone tried to guess! But nope, there are several cells that beat the VTC5. Two that come to mind immediately (that beat the VTC5) are the 25R and the VTC6, both of which run cooler and have a higher capacity than the VTC5. You probably haven't heard of the specific battery I'm thinking of unless you've worked a decent amount with batteries, though; it's not terribly popular with hobbyists (part of that, of course, is that it can be hard to get.)

bigger_cheese 10y ago

In 2010 I experimented with Graphene as the Anode of a Li Ion battery. The results at the time were pretty promising but we (the lab at my uni) were synthesizing all of the material ourselves - there was no graphene supply chain and it was very expensive. We always talked about specific capacity (q, charge per unit weight) so all the numbers I'm quoting will be in that - you can multiply by voltage to convert. We were obtaining specific capacities around 500 mAh/g. Vs q= ~370 mAh/g max for graphite anode. I recall based on theoretical modelling ~660 MAh/g could have been achievable with graphene. This pales in comparison to tin or cobalt anodes, which back in 2010 had q = 990 or so. We were not really optimizing for energy density. Rather with carbon based anodes we would see much better cyclical performance due to the lower volume expansion during Li intercalation. So you would be able to get much more charge/discharge cycles without the loss of performance you'd typically see in a higher energy density metal based anode. I work in a different industry now and have not followed battery development closely. I'd speculate a similar thing has happened in the "real world" the energy density may not have improved significantly since 2006 but the cycle life is probably better.

logicallee 10y ago
multiply with what voltage? sorry I'm being dumb - can you say the number?