Thank you for the clear information, Dr. Wu. There are loads of anecdotal stories of danger and safety out there, but this video was amazingly helpful.
This is an excellent over-view of battery fires, without too much confusing chemistry for some people. In LFP (lithium iron phosphate) cells, the oxygen atom is attached to the phosphorus atom; whereas, in the other battery cell forms, the oxygen atom is attached to a metal atom. Is this the main reason an LFP cell is more resistant to mechanical and thermal abuse? What can firefighters do to abate a battery fire, since the cell's chemistry provides its own oxygen for a fire? Would a liquidized gas (CO2, nitrogen, hydrogen) dampen the fire?
Thanks. Yes, that's correct. Generally speaking, the oxygen is more tightly bound in LFP than a chemistry such as LCO meaning potential thermal hazard is a bit lower. Also, LFP has a more stable atomic structure (olivine) than LCO (layered) which means over-discharge is a bit less detrimental. Still challenging to stop battery fires. There are a few solutions such as fire blankets and vermiculite based extinguishers being proposed but I think we still need better approaches.
definetly one of the best teaching videos about Li - Ion Batteries i have seen so far .. (but i still have to watch it at half speed ) Nice video ..., but what is adding to the confusion is that different sources (youtube videos) mention different temperatures ... 60 degree Celsius a batterie starts degrading ... (e-Scooter reached 60 degrees Celsius during normal , modest travelling for 10KM, ambient temperature was about 10-15 degrees Celsius ) 70 degree , separator starts decomposing ... 100 degree Celsius , Elektolyte with Anode reaction .. 130 vs.160 degree Celsius C seperator starts melting ...
Thanks and good points. The exact numbers can change depending on the specific materials used. For example different electrolytes and additives can change the thermal stability and there are different types of separator material being using. So, this video hopefully gives some starting points to consider but the exact values can vary depending on the specific materials used.
I see your accurate ; but it must be pointed out to people - batteries do not need to be abused to catch fire. Recently a ship containing brand new just produced EVs had brand new never abused batteries catch fire burning the entire ship up. It is critical for buyers or potential buyers to realize there is a risk of fire with EV batteries even if you do not abuse them at all. This is due to dendrites; deposits that can build inside the battery which can short basically at random causing a fire; once one battery catches fire it spread to thousands of other batteries and there is really nothing that can stop that fire.
Good point and agreed that there are other causes of failure in a battery also. As the quality control of battery production increases and also improved safety designs are implemented hopefully this will decrease the likelihood of these events, but right now there is still a risk to be managed
Thx for a very thorough & understandably presented video. I've been looking for this info for weeks, but YT didn't show it to me. I understand now that I prevented a runaway when I touched a (1 cell) vape power source. It was getting very hot. I partly unscrewed the base to stop it. I CAN imagine the toxicity of hydrofluoric acid (HF) as a gas. OMG
How much safer is the LFP battery as some EVs have this type of battery? I have seen LFP penetrative tests on TH-cam that seem to be a lot less dramatic.
The exact numbers depend on the design of the battery, but LFP in general releases about half the heat of NMC and ~a quarter of the heat of NCA cells with a higher decomposition temperature as shown in slide 11. Safety characteristics ultimately depend on a number of things such as nail penetration characteristics, heat release when over heated/over charged etc.
Great question. The various additives can modify the exact number but reference such as Wang et al 2006 Journal of the Electrochemical Society 153 A329 "Thermal Behavior of Lithiated Graphite with Electrolyte in Lithium-Ion Batteries" gives data on this. iopscience.iop.org/article/10.1149/1.2139955
Most data sheets specify 2.5V and 4.2V as the discharge and charge limits. Are these open circuit voltages, or terminal voltages? Is the degradation of the cell cause by terminal voltage or (in some sense) the open circuit voltage?
Ideally you don't want the terminal voltage to go beyond these levels, but in reality its the internal battery voltage which is important though in some cases it can be difficult to exactly measure it.
This video is very helpful, very nice work. I think that lithium batteries are a bit dangerous, they are almost everywhere. I was thinking that it would be possible to safely store it in large quantities and quickly put it out if there was a fire.
Thanks. The technology is getting safer but quality control and technology is key. Since the market is increasing so rapidly not all cells have the same quality control and therefore we need to be careful and also plan for the worse case. There are increasing numbers of products focusing on addressing this issue
@@BillyWu In your description of the various stages of thermal abuse, at 300 deg C, the lithium Oxide disassociates and oxygen is released, thereby feeding the fire. For LFP batteries, does a similar event occur?
@@exsollertan7366 Good question, in one of the later slides I show the onset temperatures of different materials. LFP is generally safer since it releases less heat and less violently but can also decompose.
Millions of Lithium Ion batteries are disposed of every day. Many, if not most, people don't give a second thought to just throwing them out with their trash. The lack of safety precautions is likely causing injury to the disposal collectors and environmental impacts in the landfills where the trash is dumped. Procedures must be developed and enforced for the disposal of these batteries.
There are many reasons why a battery might fail and subsequently catch fire. If operated too aggressively or in extreme environments this can cause the battery to overheat which can cause thermal runaway. Equally if charged too quickly this can cause metallic dendrites to form which can cause short circuits and overheat; leading to thermal runaway. Other mechanisms also exist so care needs to be taken
Thanks and good question. Sustainability of batteries could still be improved with some elements of the materials extraction and manufacturing being a bit carbon intensive. Safety is still an issue but there are new battery types which aim to improve this (i.e. solid-state batteries). Overall both elements are improving.
Probably best not to. There's been a number of battery safety incidents in India related to high ambient temperatures. Where possible remove them or at least put them in shaded areas
Amazing presentation. I love that the entire presentation is super clear, detailed and to the point. Love it.
Thanks. Glad it was clear and helpful
Dr Wu, I'd like to thank you so much
Thanks for watching
Thank you for the clear information, Dr. Wu. There are loads of anecdotal stories of danger and safety out there, but this video was amazingly helpful.
Great to hear and glad it was useful
Another excellent presentation. Thanks again Billy. Best wishes John
Many thanks
Really love the deatailed explanation provided in this video.
Glad to hear it helped
Thank you Billy, your vocabulary and articulation skills are spectacular, keep up the great work.
Thanks!
Very impressive and simplified over-view on the battery related fire.✌
Thanks
Thank you Dr Billy Wu. Excellent clear descriptions in all of your videos. Very concise and organised.
Thanks. Glad to hear it was useful
This is an excellent over-view of battery fires, without too much confusing chemistry for some people.
In LFP (lithium iron phosphate) cells, the oxygen atom is attached to the phosphorus atom; whereas, in the other battery cell forms, the oxygen atom is attached to a metal atom. Is this the main reason an LFP cell is more resistant to mechanical and thermal abuse?
What can firefighters do to abate a battery fire, since the cell's chemistry provides its own oxygen for a fire? Would a liquidized gas (CO2, nitrogen, hydrogen) dampen the fire?
Thanks. Yes, that's correct. Generally speaking, the oxygen is more tightly bound in LFP than a chemistry such as LCO meaning potential thermal hazard is a bit lower. Also, LFP has a more stable atomic structure (olivine) than LCO (layered) which means over-discharge is a bit less detrimental. Still challenging to stop battery fires. There are a few solutions such as fire blankets and vermiculite based extinguishers being proposed but I think we still need better approaches.
Excellent presentation Dr. Wu
Thanks!
Thank you very much for your clean explanation !
Glad it was helpful!
@@BillyWu yeah it was very helpful to me that why battery fire occurred.
definetly one of the best teaching videos about Li - Ion Batteries i have seen so far ..
(but i still have to watch it at half speed )
Nice video ..., but what is adding to the confusion is that different sources (youtube videos) mention different temperatures ...
60 degree Celsius a batterie starts degrading ... (e-Scooter reached 60 degrees Celsius during normal , modest travelling for 10KM, ambient temperature was about 10-15 degrees Celsius )
70 degree , separator starts decomposing ...
100 degree Celsius , Elektolyte with Anode reaction ..
130 vs.160 degree Celsius C seperator starts melting ...
Thanks and good points. The exact numbers can change depending on the specific materials used. For example different electrolytes and additives can change the thermal stability and there are different types of separator material being using. So, this video hopefully gives some starting points to consider but the exact values can vary depending on the specific materials used.
Thank you very much. Very clear.
Thanks
I see your accurate ; but it must be pointed out to people - batteries do not need to be abused to catch fire. Recently a ship containing brand new just produced EVs had brand new never abused batteries catch fire burning the entire ship up. It is critical for buyers or potential buyers to realize there is a risk of fire with EV batteries even if you do not abuse them at all. This is due to dendrites; deposits that can build inside the battery which can short basically at random causing a fire; once one battery catches fire it spread to thousands of other batteries and there is really nothing that can stop that fire.
Good point and agreed that there are other causes of failure in a battery also. As the quality control of battery production increases and also improved safety designs are implemented hopefully this will decrease the likelihood of these events, but right now there is still a risk to be managed
Over discharge also caused expansion in one of my batteries
Sorry to hear. Probably worth disposing of this safely
perfect explanation of the events ❤
Thanks. Glad to hear it was useful
Thank you professor, I gone your papers all are great work.
Thanks
Thank you for such an informative video
Glad it was helpful!
Thx for a very thorough & understandably presented video. I've been looking for this info for weeks, but YT didn't show it to me. I understand now that I prevented a runaway when I touched a (1 cell) vape power source. It was getting very hot. I partly unscrewed the base to stop it. I CAN imagine the toxicity of hydrofluoric acid (HF) as a gas. OMG
Glad to hear it was useful. Yes, when these batteries fail things can get pretty bad and the more we can share information about this, the better.
🔋 Thanks Billy
How much safer is the LFP battery as some EVs have this type of battery? I have seen LFP penetrative tests on TH-cam that seem to be a lot less dramatic.
The exact numbers depend on the design of the battery, but LFP in general releases about half the heat of NMC and ~a quarter of the heat of NCA cells with a higher decomposition temperature as shown in slide 11. Safety characteristics ultimately depend on a number of things such as nail penetration characteristics, heat release when over heated/over charged etc.
Great work, Billy. Is there any reference for the SEI decomposition at 70C ?
Great question. The various additives can modify the exact number but reference such as Wang et al 2006 Journal of the Electrochemical Society 153 A329 "Thermal Behavior of Lithiated Graphite with Electrolyte in Lithium-Ion Batteries" gives data on this. iopscience.iop.org/article/10.1149/1.2139955
Batarya yandığında maksimum ne kadar ısı verir ?
Most data sheets specify 2.5V and 4.2V as the discharge and charge limits. Are these open circuit voltages, or terminal voltages? Is the degradation of the cell cause by terminal voltage or (in some sense) the open circuit voltage?
Ideally you don't want the terminal voltage to go beyond these levels, but in reality its the internal battery voltage which is important though in some cases it can be difficult to exactly measure it.
This video is very helpful, very nice work. I think that lithium batteries are a bit dangerous, they are almost everywhere. I was thinking that it would be possible to safely store it in large quantities and quickly put it out if there was a fire.
Thanks. The technology is getting safer but quality control and technology is key. Since the market is increasing so rapidly not all cells have the same quality control and therefore we need to be careful and also plan for the worse case. There are increasing numbers of products focusing on addressing this issue
Biggest problem when a large amount burns or when in a parking garage.
@@bendaistvan79 Definitely. Hazards go up significantly with size of system
@@BillyWu In your description of the various stages of thermal abuse, at 300 deg C, the lithium Oxide disassociates and oxygen is released, thereby feeding the fire. For LFP batteries, does a similar event occur?
@@exsollertan7366 Good question, in one of the later slides I show the onset temperatures of different materials. LFP is generally safer since it releases less heat and less violently but can also decompose.
Good sir, in this video, you means that the BMS is very important to install in our battery pack? Thank you ✌️✌️✌️
Yeah, A good BMS is essential to make sure a battery pack stays within operating limits to avoid failure
Millions of Lithium Ion batteries are disposed of every day. Many, if not most, people don't give a second thought to just throwing them out with their trash. The lack of safety precautions is likely causing injury to the disposal collectors and environmental impacts in the landfills where the trash is dumped. Procedures must be developed and enforced for the disposal of these batteries.
Definitely a hot topic!
Did you have any known cases of injured garbage men you can share? Or are you making that up from speculation?
What causes the Li-Ion battery to fail, and cause it to explode and catch fire very easily?
There are many reasons why a battery might fail and subsequently catch fire. If operated too aggressively or in extreme environments this can cause the battery to overheat which can cause thermal runaway. Equally if charged too quickly this can cause metallic dendrites to form which can cause short circuits and overheat; leading to thermal runaway. Other mechanisms also exist so care needs to be taken
Thanks!
Glad it was helpful/interesting
Nice explanation - but still have to question the technology - is it really green, safe and even futuristic? I give low marks on all accounts.
Thanks and good question. Sustainability of batteries could still be improved with some elements of the materials extraction and manufacturing being a bit carbon intensive. Safety is still an issue but there are new battery types which aim to improve this (i.e. solid-state batteries). Overall both elements are improving.
hello is it safe to leave a lithium battery in my hot car during summer? it gets up to 140f in my car (60c).
Probably best not to. There's been a number of battery safety incidents in India related to high ambient temperatures. Where possible remove them or at least put them in shaded areas
fyi dendrite that are formed CANNOT short ciurcuit the battery
So much explanation of batteries but nothing about gasoline tanks.
No need to abuse them they self destruct 😂
💯
This is a fire and not an explosion. Get your facts right
Perhaps you'd like to get your manners right! (and explain your point of view)
What happens when gas pressure builds up within the battery cell?