Billy Wu - 2020-12-23
Lithium-ion batteries are at the heart of modern day consumer electronics and electric vehicles, yet improvements in the technology are still needed for further industrial application. In this video, the basics of lithium-ion batteries are discussed along with comparisons of different types of batteries, the manufacturing process and industry landscape. 00:00 Introduction 00:15 Why batteries? 01:41 Battery technologies 04:30 How does a battery work? 06:15 Key performance metrics 08:14 Battery industry structure 09:49 Do we have good chemistry? Anodes, cathodes and electrolytes 13:48 What is the perfect cathode? LCO, LMO, LFO, NMC, NCA 15:03 How do we make batteries? Battery manufacturing 16:16 The C-rate and Amp-hours (Ah) 17:16 Discharge curves 17:51 Watt about energy? 19:22 Form factors - Prismatic, cylindrical and pouch cells 20:17 How do we make better batteries 21:08 Summary Check out my other video on battery fires! Battery fires! What happens when batteries are abused? https://youtu.be/VWMfeseybt4 #Batteries #Energystorage #Materials Twitter: https://twitter.com/ICBillyWu Personal website: http://www.imperial.ac.uk/people/billy.wu About us: http://www.imperial.ac.uk/design-engineering/
Very informative video on battery basics! Thanks a lot Dr. Wu! Can you make a similar type of video explaining the working of the ANSYS Fluent battery Model (E-chemistry Models)??
I sure wish I had found this when I started researching batteries! You managed to summarize hours of material into an entertaining 23 minute video. Thanks and well done!
Glad to hear it was useful
Hello Brandan, I am just starting my research on batteries. I would like to connect with you and seek some guidance.
Slides like no. 5 are very useful when comparing results reported in different papers. But, there are just too many parameters to keep track of! The papers use variety of different parameters like energy density, power density, aerial capacity, volumetric capacity, voltage variations, driving range etc. to quantify the battery/electrode performance. I think it should be made mandatory to narrow down the performance to a fixed set of metric parameters. That would make it easy to assess the potential of any new technology.
Prof. Wu, can you provide such 'now' and 'future' data for all possible metric parameters? Also, how are the 'future' values determined? Is it based on comparison to IC engines?
Nice comments Kunal. You're right that there are many different parameters. Unfortunately, it is a complex space and in reality we need to consider all of these together. Again these metrics can be made to look better if you look at a single one. For example it's relatively straightforward to make a high energy cell or high power cell but difficult to get all into the same cell at low cost. I know a range of people are working on standards for these metrics to make them more transparent and comparable, so that would be my hope for the future.
Excellent 101 on batteries - simple, clean and organized! Thank you!
Glad it was helpful!
Thank you for a great lecture. I wonder if you wouldn't mind answering a question - do you think it is feasible for batteries at some point to reach energy density parity with thermal engines operating on hydrocarbon fuels ~ 10 MJ/kg. This means the battery pack for a BEV would have to increase by a factor of roughly 10 compared to the state of the art today (Tesla).
In theory a lithium-air battery which has the highest energy density would get you to about 5-11 kWh/kg but that's the theoretical value and in practice this would be much lower due to the other supporting components. Hydrogen has an energy density of about 33 kWh/kg which is very attractive but again needs considerations of the fuel cell and the volumetric energy density isn't as good. I think in the short term we see a pathway to >400 Wh/kg with reasonable lifetime and maybe 500 Wh/kg but the metal air systems still have challenges.
@Billy Wu very interesting thanks for the feedback. 👍
Very informative presentation! Thanks a lot Dr. Wu!
Thank you Dr. Wu for the very informative video. I’m also a PhD student at Imperial.
Thanks. Glad you found it useful
Hello Dr Wu. Great insight. I just have one question at 6:07 minutes in the figure . On the left side when you are describing the full cell packaging i believe the direction of the current is wrong. Inorder to light the bulb the electron will flow from negative terminal (anode) to positive terminal (cathode).
Thanks Ali. You're right! I never noticed that till now :)
👍Well done! Most of the important Li battery attributes explained in a short video, best I've come across.
Thanks!
EXCELLENT, comprehensive and thorough video, presented in a succinct and straightforward fashion. Thanks so much!
Glad you enjoyed it!
now this is getting epic. Definitely one of the cleanest presenters on youtube.
Thanks Evan. Appreciate the comment
Hi Dr. Billy - Covered all aspects of battery design! Very nice consolidated demonstration. Thank you Sir!
Glad it was helpful!
Very clear presentation! Thanks for the lecture :)
Thanks
Dr Billy wu, highly useful stuff.
Thanks for sharing the knowledge on batteries.
Great to hear it was useful
Thanks Dr Wu! How we can quantify the power density of a battery? Imax*Vnom?
Hello Dr. Wu, excellent video. Can you recommend a book who is just getting started into LIBs and their thermal management? Thanks.
Thanks. I recommend Gregory Plett's excellent course on battery modelling. It's available online for free also!
Modeling, Simulation, and Identification of Battery Dynamics
http://mocha-java.uccs.edu/ECE5710/index.html
Battery Management and Control
http://mocha-java.uccs.edu/ECE5720/index.html
Great overview of the battery basics! Thanks for sharing.
Glad it was helpful!
Prof. Wu, thank you very much for this Lecture.
Glad it was helpful!
I wish I could Like this video several times. Very informative Dr Wu. Thank you many times. I'll instead share this on several platforms.
Thanks for the comments. Appreciate it and glad it was helpful
Thanks Dr. Wu, this was very interesting and well explained
Glad it was helpful!
@Billy Wu So happy that this kind of great content is not hidden behind a paywall and enough condensed that one does not need to read a great number of papers to get such an overview about the current state of the technology. You're doing humanity a great service sir.
Hi Dr.Bill Wu good to watch your YouTube videos.
It's very informative.
Very useful information for someone likes me who has zero knowledge on battery. Thank you for the effort
Glad it was helpful!
I got one thing to say Dr. Billy...
Wuuuuuuu !!!!
You did a fantastic job with this video. I couldn't figure out the importance of graphite and how it relates to lithium. According to this video, it seems as though no matter what techniques they use to improve the current state of batteries, Lithium will continue to be an essential ingredient for battery makers worldwide. And I hope that's the case because that's what I'm invested in
Thanks! Glad you found the video useful. In terms of energy density lithium based batteries are currently the best performing and mature technology for automotive, so as the world transitions to electric vehicles nearly all of them will be likely lithium-based. There are lots of different types of lithium-based batteries which are often defined by the materials in the anode/cathode but all use lithium in them. Graphite is just one of the anode materials which is used to store the lithium-ions. You can think of lithium like books and graphite like a bookshelf. Other technologies like sodium-ion are interesting and potentially cheaper but still need more development work.
@Billy Wu Dr. Wu, thank you for the swift reply. I'm not asking for financial advice, but I need your help. I was thinking of investing a good chunk of money in a company called Sunrise New Energy. They're based in China and they make graphite anodes and the biggest battery maker (CATL) has purchased 2 orders of their product totaling $11 million. But I'm afraid to invest in their graphite anodes because you mentioned in this video that graphite will eventually be replaced with something better. How long do you think graphite anodes will be around before they're replaced?
@Conservative Hero My view is that graphite is likely still to be the main anode material for the near/medium term. Technology transitions in batteries take time, partly due to the need for technology validation and supply chain build up. Silicon and lithium anodes are theoretically better from a performance perspective, but graphite is very cost effective but as always recommend doing your won research. Benchmark Mineral Intelligence has very good data on supply volumes and there are different types of graphite to consider.
Hi Prof. Wu...very nice and clean presentation and was really useful information. Thanks
Glad it was helpful!
Highly fact density. A good presentation. Thank you.
Glad it was helpful!
best presentation I have seen on Li-ion tech on youtube . hats off :)
Thanks a lot
Dr, I saw both videos, those are very nice and informative. Can you suggest book name to understand Li as element in detail. Thanks.
Linden's Handbook of Batteries is a good start (https://www.amazon.co.uk/Lindens-Handbook-Batteries-Thomas-Reddy/dp/007162421X). Also consider the MOOC from Gregory Plett and his associated book. http://mocha-java.uccs.edu/ECE5710/index.html and http://mocha-java.uccs.edu/BMS1/
Thank you, very informative
Glad it was helpful!
I like this summary. Very insightful.
Thanks
Hi there I enjoyed your video. One thing is not clear to me though; when a Li Ion battery is discharging the LI ions must flow from the anode to the cathode how do the ion's overcome the 3.7v potential ???? and if you can point me to paper that talks about this that would be great!! - well no reply from Billy so this is not the guy to ask questions of
Sorry, I don't check the comments that often. The voltage of a battery is made up of the difference between the anode and the cathode. The overall cell voltage varies from 4.2 V (fully charged) to 2.7 V (fully discharged) for most battery chemistries. The 3.7 V quoted number is the nominal (~average) voltage of discharge. This series of talks from nanoHUB-U on rechargable batteries gives a great overview of the fundamental science https://www.youtube.com/watch?v=ghbiKe45s2c&list=PLtkeUZItwHK4cJIeupONcZkgHFIzPrXXa&ab_channel=nanohubtechtalks
Perfect. Thank you!
Glad it helped!
Bugging me for a while now is "why do manufacturers make single-layer cells instead of 2-layer cells"?
If they adhered anode graphite to both sides of the anode metal sheet, cathode nickel to both sides of the cathode metal sheet, and jellyrolled round batteries with one additional separator sheet, they would have, on packaging and pumping in electrolyte, a cell with just slightly lower current but double the voltage, with slightly less anode and cathode metal sheet than a single-layer cell.
A 1.8 times increase of energy density.
Good question. Many battery electrodes are actually coated on both sides to improve cell level energy density (though most of the time for simplicity we just show a single side coating. This reduces some of the need for current collectors as they can be shared. On the point about voltage, in most cases connecting cells in series in the same electrolyte can lead to its decomposition and hence poor lifetime so is not generally done, however there are bipolar cell designs for solid-state batteries where you can isolate the electrolyte a bit better to mitigate this issue
Does lithium have the same "memory effect" as nickel-cadmiun?
Nope. Lithium-ion batteries don't suffer from the "memory effect" that was found in older batteries so you can use these straight out the box.
thanks for this video...very informative
Thanks
As a denizen of Canada, how would our rather nasty winter temperatures going to affect battery efficiency?
Great question. The low temperatures will increase the resistance of the battery which unfortunately will decrease the efficiency. A thermal management system might well be needed to keep the battery in it's optimum temperature range (~10-30°C) but pre-heating often consumes energy, leading to lower system efficiency.
Nice and informative Talk
very educative & many thanks for sharing
Thanks. Glad to hear it was helpful
Please upload the vedio of heart of Na-ion Batteries also ...nice vedio
Thanks! Am working (very slowly) on a sodium-ion video
@Billy Wu please fast go ahead sir ,I am waiting 😊😛🙏
Great Job!
Thanks!
🖤 thank you very helpful
Glad it was helpful!
Very good Billy!
Thanks
But Watt about energy?
Excellent video
Thanks internet stranger. Hopefully the video will charge interest in the subject
What makes LFP safer than NCA? or vice versa. A source would be enough
Great question! The safety differences come in part due to the thermal stability of the cathode materials. LFP has something called a olivine crystal structure and NCA is a layered material. This is basically how the atoms stack up with some more thermally stable than others. Whilst LFP has a lower capacity because of this it is more stable with it more difficult for the oxygen in the materials to decompose which is one of the safety issues. This paper gives an excellent review on safety and thermal runaway "Thermal runaway mechanism of lithium ion battery for electric vehicles: A review" https://www.sciencedirect.com/science/article/abs/pii/S2405829716303464
@Billy Wu Thank you for the explanation. Excellent video
👍🏻
This is some serious shit, need to watch at least twice to absorb all the info, btw did you see my 2nd life storage project/product?
Thanks. Just had a quick look. Looks interest. Hope the project goes well
great information pack
Thanks!
this is peak youtube
too boring to pick up any understanding. next time give it some life - not like reading a text-book.
go less words per minute, half as much.
Kunal Pardikar - 2020-12-24
Hi Professor Wu, very informative video! I was thinking about the hexagonal representation of different chemistries on slide 8. Should Voltage be there as a parameter? Maybe its included in the power term? For Li-Sulfur chemistry, how will the hexagonal map look like? Maybe better than NMC/NCA?
Billy Wu - 2020-12-24
Thanks Kunal. Good question. Voltage is important and is somewhat captured in the specific energy of the material as this will be related to the product of the nominal voltage and the specific capacity of the material. Li-sulfur will have better specific energy than NMC and very good cost since sulfur is quite cheap. However, the lifetime of these devices are quite poor due to instabilities in the lithium and also power rate is quite poor since sulfur is not a very good electrical conductor.