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CT scans of batteries
- vitruvius 4y agoThe LG lithium ion cell that's second on this page is the one inside the Tesla Model Y battery pack.
- jaywalk 4y agoThank you. I was just about to come back here and ask where it was.
- anon946 4y agoThat's interesting and somewhat surprising. I'm not knowledgeable about battery design by any means, but I would have thought that there would be a better way to make a battery pack for a car than connecting thousands of small batteries together.
- tppiotrowski 4y agoIt's often not the best design but the one that's cheap, scalable and has momentum behind it that wins out.
- ggm 4y agoif I remember my basic chemistry, batteries don't deliver voltages at the level of 10/20/100v directly often, its more commonly 1/2v or 0.5v class voltages. You have to have a much more 'aggressive' chemical reaction to deliver higher voltages. And, the same with current: a single surface between two reacting things delivers less current. Its a function of surface area. Same with capacitance: you sometimes need 'more' surface to big up the effect. Therefore all you have is stacking it up. parallel or serial, thats what there is to get higher voltages, more current draw, longer life per-cell. Inside a lead acid battery its multiple surfaces, sub-cells. It's normal. inside almost any domestic battery I suspect its sub-cells, sub-cells all the way down. A giant roll of surface, to increase the area in contact might be one way of getting "more" in terms of current draw or lifetime. I bet that its voltage remains close to the constant in this, hence Tesla "stacking" up the rolled cells, to boost voltage.
- MobiusHorizons 4y agoThis strategy is one of the remarked upon things when I first heard of Tesla (something like “this California startup is powering their electric car with laptop batteries”) ironically laptops have almost all transitioned to lithium polymer (pouch cells) instead of the 18650s they used back then. Not all car manufacturers use teslas standardized cell technique, as it does have some downsides. I guess time will tell, but I doubt Tesla will abandon this technique any time soon.
- CarVac 4y agoSmaller cells are safer due to better containment of thermal runaway, letting them use a better-performing but somewhat riskier cell chemistry.
- Bayart 4y agoUsing standard form factors and manufacturing techniques made it much easier for Tesla to get batteries off the ground through their partnership with Panasonic. The extra space left by the gaps between cells also has the advantage of being ideal for cooling (battery performance and safety is correlated to temperature).
- pjc50 4y agoSeparating the cells allows makes it easier to cool them. It also provides more inert metal between them in case of fire. A certain amount of stacking is necessary to get up to a decent voltage, as others have pointed out. But even "100 brick-sized cells" would be a more dangerous prospect than "thousands of 18650 cells".
- michaelt 4y agoThe Nissan Leaf uses larger cells [1], each roughly the size of a ream of printer paper. So there are real car designers who agree larger batteries are worth considering. Of course, the Leaf makes a bunch of other decisions that are different to Tesla - lower price point, smaller battery/reduced range, air-cooling batteries instead of water-cooling, a (now abandoned) battery lease scheme, and suchlike. [1] https://www.google.com/search?q=nissan+leaf+cell&tbm=isch https://www.google.com/search?q=nissan+leaf+cell&tbm=isch
- raydiatian 4y agoGlad they finally did more scans, and released the backlog of them. Having so much nostalgia reading through the game boy scans.
- boboche 4y agoNo 4680 cells, its 2170.
- moffkalast 4y agoStill very cool, and it shows the single tab connection that's the bane of old cylindrical cells that the 4680 solves. I do wish Samsung would already release some of them to the public ffs. Surely they can come up with a price that would beat what Tesla's offering for bulk and sell it on the open market.
- baybal2 4y ago
- ggreer 4y agoOnly the Model Ys that come out of the Texas factory have 4680 cells, and their production volume is still ramping up.[1] 1. https://twitter.com/Tesla/status/1571037989282906112 https://twitter.com/Tesla/status/1571037989282906112
- sam1r 4y ago>> Create an account and continue browsing on a computer to experience the demo assets. Super cool, but requires account to check out a scan-which won’t work on mobile regardless, fyi.
- pontifier 4y agoThe viewer is really worth checking out. The full model seems to be there, though some settings look disabled. I can imagine making changes to a battery production line, scanning a few samples, and using the scans to tweak angles, speeds, stops etc. I'm sure these scanners are expensive. Very cool though.
- dsalzman 4y agoThe company behind these scans is https://www.lumafield.com/ https://www.lumafield.com/ - a really cool way to do marketing for your product. Love it!
- saxonww 4y agoI was thinking this is "will it blend?" applied to some company's product. Looks like they sell industrial CT equipment and software.
- richk449 4y agoAnyone know what energy the x-ray source is in their system? Seems really well designed, but if it doesn't have energy energy to penetrate the devices we need to scan, none of that will matter.
- habi 4y agoThey don't mention anything on their website, but I guess - from looking at their machine - that they use an x-ray source which goes to the range of 150kV, since they also show larger items with more metal volume being scanned. *source: I work with two of the machines here: https://www.bruker.com/en/products-and-solutions/microscopes/3d-x-ray-microscopes.html https://www.bruker.com/en/products-and-solutions/microscopes... (and one more from Bruker which is so old that they don't show it on their website anymore).
- richk449 4y agoI need a 225 kV (or higher) system with good 3D tomography. Any idea what the most cost effective option is?
- habi 4y agoWhat is 'good' tomography? High resolution, fast scanning or only imaging a certain kind of samples? I presume you're not scanning biological material with such a high acceleration voltage, so I'd look into NDT systems from https://www.nikonmetrology.com/en-us/x-ray-ct https://www.nikonmetrology.com/en-us/x-ray-ct or https://www.zeiss.com/microscopy/en/products/x-ray-microscopy.html https://www.zeiss.com/microscopy/en/products/x-ray-microscop...
- deleted 4y ago[deleted]
- yanowitz 4y agoPairs nicely with this great book about all kinds of electronic components -- https://nostarch.com/open-circuits https://nostarch.com/open-circuits
- pxmpxm 4y agoReceived mine last week, fantastic book!
- holoduke 4y agoI like the way the website uses the animation. Well done.
- londons_explore 4y agoThe Tesla 2170 cell has a big hole down the middle of it... That seems like a missed opportunity for a watercooling pipe, or anything else to use that space effectively.
- withinboredom 4y agoI somehow suspect water and electricity after a crash don’t mix well…
- gambiting 4y agoI mean, those batteries are liquid cooled anyway.
- oliveshell 4y agoI haven’t read the paper, so I can’t comment on its merit, but it appears you’re not the first to have that idea: Performance assessment of a passive core cooling design for cylindrical lithium-ion batteries https://doi.org/10.1002/er.4061 https://doi.org/10.1002/er.4061
- baybal2 4y agoCylindrical cell life is limited by graphite expansion. You can only have a roll that long before tension from anode expansion will start mechanically damaging it. Manufacturers intentionally leave some free space to let the roll expand, and shrink
- exabrial 4y agoEven in 2022, hijacking the scroll wheel still isn't cool or 1337.
- haggy 4y agoI disagree in this case. Normally I'd fully agree with you but I think this animation style works really well given their use-case.
- dnfa 4y agoI always thought scroll jacking was taking over the behavior of the scroll? This seems different, as it's using the position on the page to run the animation but not controlling the scrolling behavior.
- Zak 4y ago> We used the measuring tools in our Voyager analysis software to decode the model number: it seems to mean that the battery is 21mm in diameter and 70mm tall. Or they could just read https://en.wikipedia.org/wiki/Battery_nomenclature https://en.wikipedia.org/wiki/Battery_nomenclature, which describes the relevant IEC standard.
- haggy 4y agoThis is not really surprising considering that it's basically a (very cool) marketing article for their equipment.
- newaccount74 4y agoI'm pretty sure that sentence was supposed to be a joke. First of all, everybody knows this, secondly you really don't need a CT scanner to measure the diameter of a thing.
- sneak 4y agoI didn’t know this.
- yieldcrv 4y ago
- throwayyy479087 4y agoThose tabs on the final item are what caused the Bolt fires. The manufacturing was incorrect, and they had to replace every cell.
- tppiotrowski 4y agoYou led me down this rabbit hole [1] Curious choice my GM as I thought the LiPo packs were more prone to distortion/swelling which can cause the membranes break and the battery to short. [1] https://cleantechnica.com/2018/07/08/tesla-model-3-chevy-bolt-battery-packs-examined/amp/ https://cleantechnica.com/2018/07/08/tesla-model-3-chevy-bol...
- s0rce 4y agoSigray has some really cool battery examples https://sigray.com/batteries/ https://sigray.com/batteries/
- joering2 4y agoHow doable (guess not) would it be to make a "gravity battery" ? A tiny but heavy balls are thrown from top and while passing thru thin channels they rotate some sort of mini-dynamo that creates electricity. Once all balls are on the bottom, generated electricity is used to rotate the whole thing and start process anew. Anyone with a napkin can elaborate why this is not feasable?
- system2 4y agoNo need napkins for it. Because of friction and other forces the dynamo does not generate enough energy to lift the balls back up and have extra to be stored for other uses. In short, you use more energy to lift them than produced. If anyone could invent such a device, the world hunger and money wouldn't be problems anymore and we would be traveling to the end of the universe already.
- minitoar 4y agoI’m pretty sure by “generated electricity” they mean from some other source.
- kamilner 4y agoThe amount of energy from a 1 tonne mass dropping 1 meter is about 10,000J (https://www.wolframalpha.com/input?i=%281+tonne+*+9.82m%2Fs%5E2+*+1+meter%29 https://www.wolframalpha.com/input?i=%281+tonne+*+9.82m%2Fs%...) The amount of energy stored in a Tesla is about 100kWh or about 3.6e8J. You would need 36,660 tonnes suspended by a meter to store an equivalent amount of energy (or 1 tonne suspended 36.7km). https://www.wolframalpha.com/input?i=100kWh+%2F+%281+tonne+*+9.82m%2Fs%5E2+*+1+meter%29 https://www.wolframalpha.com/input?i=100kWh+%2F+%281+tonne+*...
- addaon 4y agoOr one Tesla Model S (~4600 lbs) suspended 17.6 km. With a range of ~400 miles, this means the storage-Tesla would have to drop ~0.027 units per unit travelled by the drive-Tesla, giving a "glide ratio" of ~36:1, which passes the sniff test on reasonableness.
- real-dino 4y agoI have some LiFePO4 batteries powering my laptop, and onboard electronics on my boat. They are very heavy, but have a super long life. Often forgotten, they are used a lot in automotive applications!
- caf 4y agoLFP cells are what the Tesla Model 3 and Y RWD from GF Shanghai use. They'd be ideal for home batteries you'd think - I wonder when they'll switch the Powerwall.
- elihu 4y agoFrom a technical standpoint that makes a lot of sense. I think the main obstacle there is that Tesla doesn't (as far as I know) actually make LFP batteries. The ones they use in their cars come from CATL. Tesla could just buy batteries from CATL and package them in a Powerwall product, but they might not be interested in doing that since there's a big risk that CATL or some other manufacturer could make an identical product without the Tesla brand and sell it at a much lower price. There's a theory that Powerwall was just a way for Tesla to not waste their excess battery manufacturing capacity when car production wasn't keeping up. I don't know how true that is, but if so there isn't much of a need for them to figure out how to sell CATL's excess battery supply.
- scrumper 4y agoVery interesting! Confused by the text about the alkaline scan (the first one). The +ve side is called the anode isn’t it, not the cathode? And electrons originate at the cathode not the anode. Or is the usual terminology inverted because it’s a battery or this particular type of battery? I don’t know much about batteries; chemistry never a strong suit.
- derkades 4y agoAs I understand it, the cathode is where electrons "leave", the anode is where they "enter". In case of a battery, electrons leave the minus side. But for a device being powered, electrons enter the minus side.
- HPsquared 4y agoI always remember it by thinking about a cathode ray tube - on that, the flying electrons are called "cathode rays", i.e. the cathode shoots out the electrons that came in from the external connection. The power supply pushes electrons into the "cathode" terminal on the device. That is, "positive current" flows out of the cathode (in the opposite direction to the electrons).
- caf 4y agoHere's how I was taught to remember it: The cathode is purr-sitive.
- motohagiography 4y agoWhat a great concept for explaining the inner workings of everyday things. From a product perspective, what a dream to have that available to take the mystery out of what you do. I'm thinking of other hidden mechanisms that people use every day that it would be socially helpful to understand, and the sponsorship ops must be amazing. I suppose there's just some people you can't convince, so a 5G transmitter might not be a great example, but maybe a speed enforcement gun, the secure element on an iphone, SIM, or chip and pin card, the brake caliper of a car with regenerative braking, a high end espresso machine, a top tier audio amplifier, etc.
- another_story 4y agoCan CT scans be used to create 3D models with internal components?
- sudhirj 4y agoMight have to apply a layer of analysis over it. From what I understand the scan is a 3D maps of point densities, so it may or may not obvious what the separate components are. If a device was made up of components that all had very different densities, maybe one could analyze the points and determine components and do a “explode” animation.
- insane_dreamer 4y agoJust discovering this site for the first time. Pretty awesome.
- caycep 4y agoHow are they getting color? My impression is CT scan is mostly measuring density and x-ray absorption. Are they doing false color based on some sort of data (vs photoshop?)
- alephxyz 4y agoLooks like a basic CT scan but using the Plasma colormap from matplotlib (or a similar one).
- ajnin 4y agoThe article mentions in passing that "The negative electrode is copper; its yellow color in our visualization means it’s denser than the other materials in the battery." So presumably the blue to yellow scale corresponds to material density.
- HPsquared 4y agoI think in this case it's just the density (absorption) but on some machines it's possible to use different energy levels of x-rays (so-called dual energy CT) to see variations in materials/chemistry, that works in a similar way to colour in the visual spectrum (different materials absorb different energy levels of light differently).
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