Professor Jeff Dahn | WIN Seminar Series
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- Опубликовано: 25 июл 2024
- On July 30th, 2013, Professor Jeff Dahn of Dalhousie University delivered a lecture entitled "Why do Li-ion batteries die and can they be immortal?".
Li-ion batteries for tablets and phones last several years. Li-ion batteries for electrified vehicles and grid energy storage need to last decades. I will explain why Li-ion batteries die and, using examples from our recent research, how changes to their chemistry can greatly improve their lifetime. It is my opinion that Li-ion batteries can eventually be made to last for 20, 30 or even 50 years.
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This guy really know what he is talking about.. thank you for your awesome presentation
Very informative description of pioneering science of Li-Ion battery charge/discharge behavior. Worthwhile for anyone who wants to understand Li-Ion battery behavior at a deeper level.
Excellent lecture. He makes complicated things see simple to understand. Thanks.
1:07:07 the longer time you spend at highest voltage the worse it is (the lifetime)
Wow, amazing presentation!
I really like this guy.
As one of the smartest people in his field, he's quite *happy to admit "I don't know"* to all sorts of important questions. My bet is that he's working very hard to find some answers to those questions...
A lot of really smart people are happy to admit they don't know something.
To become smart and acquire knowledge you first have to admit you don't know something. Stupid people think they already know everything. Smart people are always happy to learn something new.
This guy is the best professor at Dalhousie
+ProgrammingTime I was lucky enough to be in his physics class in my first year :)
+Nawaf Haboobi Me too! Such a baller.
+Mathew Kallada Yes he is! I graduated in 2013 and I have seen many instructors in 4 years, few of them were inspiring, Jeff Dahn and 3 others had a big influence to my life!
Very good talk and q/a session; thanks.
Great informative video for anybody using LiOn batteries regarding heat, charge time, and storage voltage effects.
Another interesting test would be how does it fare in -10, -20, -30°C
It would be interesting to see a followup video on solid state lithium batteries, seeing as the electrolyte seems to be the big problem here.
Amazing lecture. I really like the professor. I am not an engineer nor do I have anything to do with batteries except being an EV enthusiast (obsessive? haha) and even I understood all of the lecture. One question though; here he says that silicon is light years away yet we hear Tesla starting to use "a miniscule amount" of silicon in their batteries to get the 90kWh pack. Anyone have anything to say about that?
Can we also deduce from this lecture that the industry has somewhat covered the part of longevity to make EV batteries that last at least 100,000 miles and now the main issue is energy density + cost?
+Emir Tunçyürek Yup, Tesla's NCA batteries do use Si, and in small amounts the volume expansion effect is not significant, but we can get the high energy density benefits.
Model 3 has a much higher amount?
www.technologyreview.com/s/601178/the-tesla-model-3-may-depend-on-this-battery-breakthrough/
Now the main issue is cost, that's pretty much it, there are materials that can provide us the high energy density, but they are too darn expensive;
This might be achieved by new chemistries/ configurations as well.
4 years later and Tesla is announcing his revolutionary Lithium Iron (Phosphate) projects for longer and faster charging batteries without Cobalt which is what Lithium batteries are dependant on, Professor Dahn and Aaron are working for Tesla's new projects and big things are foreseen.. 1 Million mile Electric batteries with 400mile range cars, and the batteries may have second or third lives as off grid electrical storage for Solar panels or Home use.
1:12:20 Keep the battery in the fridge it will last longer
😃😃 I am keeping my car in the fridge.
Good news for electric vehicles in cold climates
At around 56:00 he is talking about special additives to electrolyte that can cure the cell heating above 4.0V. From his talking it sounds like "violin carbonate" - not sure if thats right and what that is? Can somebody explain a bit deeper? Is it only for LCO cells or also for NMC chemistry?
vinylene carbonate
you I recharged a nanrobot 4d+ battery after every use or wait until battery level low? most says to recharge every time but then you are using the limit battery cycles and the battery when last very long... can somebody explain?
charge before using
He does not mention deep discharge, right?
turns out, the diesel guys where more desperate than exited lol. :D
This is to increase life of battery, which is great, but how about capacity per volume of the battery?
it's not very important, more important would be gravimetric energydensity since it also affects range - there's generally enough space in a groundvehicle
@@yourlydontknowjack if you look at which EVs are efficient and which are not, there is barely any correlation to vehicle weight. Your claim is valid in theory but bullshit in practice.
Good old battery talk :)
"keep em in the fridge" - does this apply for the freezer too? -20`C anyone?
For storage ok.
Welcome to Tesla!
can someone answer me one question. Why is the battery module a roll ? All other manufacturers are making their cells a block - to use as much space as possible - apart from tesla.
Tesla probably originally went with that format for cost reasons since it was the preferred consumer format (for laptop batteries). An added benefit is that they take advantage of the gaps in between the cells for fire retardant and cooling purposes. Besides, is space an issue, or is the bigger issue weight and cost?
My guess is surface area for temperature control.
Thank you for those insights. Amazing. I think i will make a tshirt on which will be written:
I love Batteries! haha
+plavix221 There's already several "I heart batteries" T-shirts avaible:
www.google.com/search?q=i+heart+batteries+t-shirt&source=lnms&tbm=isch
I allready have shirt written: Acid powers my life, Acid powers my dreams, Acid rulez
with pic of lead-acid voltage meter scale from some old charger underneath (i live in off grid squated house...so it is true)
welcome to Tesla
27:00 BYD have chosen LFP batteries in their EV bus market domination in China - yet Prof Dahn shows/says its a poor choice. Interesting - theory vs practice. I wonder what level of temp control BYD used in practice?
LFP batteries are generally lower energy density, but longer lasting. Since a bus has high weight and drives long distances, LFP is good for that.
I can't see him wheeling around an IV bag full of lorazepam, but I'm sure it's there somewhere.
Great lecture! But why is he making so much advertising for Tesla? Is that ok in the US? But good lecture anyway. As an engineer I can imagine how much work has been put into getting all these data points...
Who else should he have mentioned in a positive way? In 2013 there was basically only Tesla, BMW i3 and Nissan Leaf (both with tiny batteries at the time). And the Volt (which was great), but that is not pure electric. And dumping on the Leaf is VERY much justified. Nissan single handedly tried to ruin the reputation of car batteries with their incredibly bad technological and customer-unfriendly decisions.
how does discharging to 0 volts damage the cell permanently?
It does
@@theophiluslamptey47 ohhhh
@@theophiluslamptey47 you seem to have some difficulty understanding the meaning of the word „how“
@@geraldh.8047 don’t be rude
@@theophiluslamptey47Get wise.
27:16 Another example why Tesla is making a big difference
Nawaf Haboobi
*Panasonic
Bad Filming. Please, I want to see the slide, not Professor Dahn.
Explanation why temperature is a problem @4:00
Why fast charging is a good idea @24:30
"Why fast charging is a good idea"
I don't think that's what he's saying at all (although subsequently it has been shown that fast charging can have a beneficial effect sometimes). I think what he's saying is that the way battery testing is normally done, there is no pause between charge/discharge, so if you test using fast charging you get a lot of cycles in in a short amount of time, which doesn't leave a lot of time for the parasitic reactions that would diminish battery capacity to occur. If you were to pause after the charge/discharge and just wait the equivalent amount of time that you would've while doing a slow charge, the effect on the battery for each of the two charging schemes would be roughly the same (which he also shows the data for). Furthermore, consider that he is showing data for which charging takes place at a carefully controlled (and possibly elevated) temperature. As he says (and you referenced), temperature has a dramatic negative effect on battery life, and for a typical user, fast charging will elevate the temperature of the battery more than slow charging, so the net effect is that fast charging, in actual practice, would be worse for you, unless you took steps to actively cool the battery and also immediately used your battery followed by immediately charging your battery repeatedly.
databeestje my own interpretation is that parasitic side reactions take place *during* the charge-discharge cycles themselves - I'm assuming that during the time the li-ion moves through the electrolyte, it is vulnerable to parasitic side reactions because it is more reactive due to missing an electron. So this is not a simple "age of cell" issue - these reactions don't happen so much when the cell is idle. (He does hint that cell *storage* is a topic for another time. No doubt!)
I'd love feedback on whether this is correct. He doesn't make that clear.
My own takeaway is that charging while hot is a bad idea. I want to know more about how driving my Leaf and how charging my Leaf affect *internal* battery temps - and thus affect these parasitic side reactions, and my battery life.
Fast charging will also destroy your battery. You took a discussion about controlled tests and twisted it into something completely different.
Take a Panasonic NCRB (Tesla), spec says 180min not to exceed 0.5c ... if it takes you any less than 3hrs to charge a single cell ... out of 7000+ cells ... you've caused permanent, if incremental, damage.
@@kikijewell2967 Fast charging while hot is actually better than fast charging when cold. You just need to make sure to cool down quickly again after charging. I believe that the parasitic reactions continue at all times, whether a battery is in use or not. But I agree that this was not shown, and they should have done this as a control.
Hi guys, there's a pirated copy of this video at: ruclips.net/video/pxP0Cu00sZs/видео.html