How To Make Li-ion Batteries Live Longer (In Depth Video)
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Doctorbass
100 GW
Damn interesting document !!
I have watched every minutes and learned great things!
The HPC is a great idea and will definitively improove developpment if additive in lithium battery.
Doc
I have watched every minutes and learned great things!
The HPC is a great idea and will definitively improove developpment if additive in lithium battery.
Doc
dnmun
1 PW
really is worth the time. i have watched it three times now. learned more each time.
1:07 is where he finally says it. length of time at high voltage and temps is what increases the oxidizing reactions of the electrolyte.
1:07 is where he finally says it. length of time at high voltage and temps is what increases the oxidizing reactions of the electrolyte.
JackB
10 W
Good news they have a faster method to measure cell lifetime,
and looked like some of those additives were pretty good -- 2000 cycles vs 500.
This has almost nothing to do with USERS making them last longer.
Nothing new that heat is not good for lithium batteries,
or you should not store them fully charged.
It was a bit of news that in fact charging faster is better than charging slower.
A lot of people think just the opposite right now, better to charge slower at low voltage,
when in fact, you should use higher voltage for a much shorter time.
and looked like some of those additives were pretty good -- 2000 cycles vs 500.
This has almost nothing to do with USERS making them last longer.
Nothing new that heat is not good for lithium batteries,
or you should not store them fully charged.
It was a bit of news that in fact charging faster is better than charging slower.
A lot of people think just the opposite right now, better to charge slower at low voltage,
when in fact, you should use higher voltage for a much shorter time.
dnmun
1 PW
a bit of news that did not make it when i listened.
i did find it amusing that nobody said a thing about how he charged all those cells to 4.4V and nobody here said a thing about that even though it is doctrine here that it ruins them to charge over 4.20V. and then he had the nerve to discharge them down to 3V as though he never heard that people here said that is the worst thing in the world to do.
i did find it amusing that nobody said a thing about how he charged all those cells to 4.4V and nobody here said a thing about that even though it is doctrine here that it ruins them to charge over 4.20V. and then he had the nerve to discharge them down to 3V as though he never heard that people here said that is the worst thing in the world to do.
Obviously he's not working with poor quality hobbyking lico with its low-quality electrolyte that's very likely to decompose at lower voltages than that found in top quality 18650 cells, that some manufacturers rate to 4.35V.
Similarly, discharging to 3.0V is probably fine with well matched cells and a good BMS, but many here run without a BMS and with poorly matched cells and avoiding deep discharge helps prevent cell imbalance and over-discharging individual cells.
Similarly, discharging to 3.0V is probably fine with well matched cells and a good BMS, but many here run without a BMS and with poorly matched cells and avoiding deep discharge helps prevent cell imbalance and over-discharging individual cells.
Doctorbass
100 GW
That is definitively something I need to test ... The cheap high power charging solution are becoming more and more popular with these Hp 3kW power supply and many other server psu...
If we manage well the dissipated heat at fast charging will have only the limit of the AC source we have availlable
That's great!
KINNINVIEKID
1 kW
Fancy a laugh ?
Watch this again but this time turn the volume down and turn the subtitles on.
The guy who did these is obviously the same one the Chinese use to translate their manuals ie the Ness Am Leaf for Nissan Leaf.
Watch this again but this time turn the volume down and turn the subtitles on.
The guy who did these is obviously the same one the Chinese use to translate their manuals ie the Ness Am Leaf for Nissan Leaf.
MitchJi
10 MW
Hi,
They were generated using automated speech to text.
dnmun
1 PW
i still would like to see where he indicated that charging at high C rates was beneficial.
when he was talking about overlap, it reminded me of how those A123 cells ended up discarded because the alignment of the separators to the electrodes was what i understood the problem to be so that means those cells were liable to have the dendrites grow out and touch the aluminum in the mylar and that was how they ended up with the black splotches we see on these recycled pouches from that. i don't really know if they are connected, but that seems plausible to me.
his comment about having a lipo cell from 1999 that still would hold a charge was interesting too. just never charge it and it will last forever. but when he talked about freezing them, i thought that might cause people to think they can charge in low low temps and my understanding is that those low temps cause plating outside of the electrode. maybe someone else understands the reactions and precipitation interactions with the electrodes better.
when he was talking about overlap, it reminded me of how those A123 cells ended up discarded because the alignment of the separators to the electrodes was what i understood the problem to be so that means those cells were liable to have the dendrites grow out and touch the aluminum in the mylar and that was how they ended up with the black splotches we see on these recycled pouches from that. i don't really know if they are connected, but that seems plausible to me.
his comment about having a lipo cell from 1999 that still would hold a charge was interesting too. just never charge it and it will last forever. but when he talked about freezing them, i thought that might cause people to think they can charge in low low temps and my understanding is that those low temps cause plating outside of the electrode. maybe someone else understands the reactions and precipitation interactions with the electrodes better.
I just started charging at close to 3000 watts, so this makes me feel better about charging at such high rates.
One other thing he said is that storing them at lower voltages is better. He had one stored at 3.5 volts and still had full capacity over 10 years later.
I always wondered why I was told to store them at 3.8 volts, it never made sense to me. I think people just said this because that is what hobby king ships them at.
So I actually like to store them at 3.7 volts, which is much lower than 3.8 I was told,.
Now I will make sure to store them as low as 3.65 volts.
One other thing he said is that storing them at lower voltages is better. He had one stored at 3.5 volts and still had full capacity over 10 years later.
I always wondered why I was told to store them at 3.8 volts, it never made sense to me. I think people just said this because that is what hobby king ships them at.
So I actually like to store them at 3.7 volts, which is much lower than 3.8 I was told,.
Now I will make sure to store them as low as 3.65 volts.
JackB
10 W
Did you miss the chart that showed A123 cell with only 100 cycles when charged/discharged very slowly.
http://www.youtube.com/watch?v=pxP0Cu00sZs#t=339
Some think slower is always better and it isn't
because it increases the time the battery is under higher voltage.
http://www.youtube.com/watch?v=pxP0Cu00sZs#t=339
Some think slower is always better and it isn't
because it increases the time the battery is under higher voltage.
eTrike said:
dnmun
1 PW
i don't think that follows from what he said. he did not ever say that charging at high rates was beneficial from what i heard.
i find that with lithium the voltage climbs very rapidly in voltage at the end of charging, the last 10% from 4.1 to 4.2 and in his charts he did show that there was a definite difference in the shifting when he changed the charge end point from 4.35 down to 4.25V.
this lecture is like over a year old and i bet his research is much further progressed especially if they are using the micro calorimeters now to measure the heat of reaction for these parasitic reactions he is interested in studying. when he mentioned how his grad student had gone to form the research group at Tesla, it made it clear why Tesla has decided to build this big plant. i think they will be able to safely gamble everything on a new chemistry that everyone will buy and they can control the market by having such huge capacity and Tesla is gonna be building cars in china soon too, so the batteries could be built here and shipped there too. then they could maintain secrecy over the process.
i find that with lithium the voltage climbs very rapidly in voltage at the end of charging, the last 10% from 4.1 to 4.2 and in his charts he did show that there was a definite difference in the shifting when he changed the charge end point from 4.35 down to 4.25V.
this lecture is like over a year old and i bet his research is much further progressed especially if they are using the micro calorimeters now to measure the heat of reaction for these parasitic reactions he is interested in studying. when he mentioned how his grad student had gone to form the research group at Tesla, it made it clear why Tesla has decided to build this big plant. i think they will be able to safely gamble everything on a new chemistry that everyone will buy and they can control the market by having such huge capacity and Tesla is gonna be building cars in china soon too, so the batteries could be built here and shipped there too. then they could maintain secrecy over the process.
teslanv
1 MW
Very interesting presentation.
I still have to wonder if really high charge rates (shorter charge times) are better. I would have liked to see the Coulombic Efficiency chart based on temp & time combined. So is 20 minutes charge time where the cell reaches 50 degrees C better than a 40-minute charge where the cell reaches 35 degrees C?
I still have to wonder if really high charge rates (shorter charge times) are better. I would have liked to see the Coulombic Efficiency chart based on temp & time combined. So is 20 minutes charge time where the cell reaches 50 degrees C better than a 40-minute charge where the cell reaches 35 degrees C?
chvidgov.bc.ca
10 kW
All this is now obsolete?
http://www.sciencedaily.com/releases/2014/10/141013090449.htm
Titanium dioxide nano anodes obsoletes graphic
http://www.sciencedaily.com/releases/2014/10/141013090449.htm
Titanium dioxide nano anodes obsoletes graphic
dnmun
1 PW
i think of titanium dioxide as a ceramic and wonder how it can be as conductive as graphite and what the electrode potential will be with TiO2. maybe that is where the hydroxide enters the reaction as an electron shuttle from the TiO2 to the electrode, which cannot be aluminum now either.
back in 1981 i did some experiments with an ultraviolet laser to photodeposit SiO2 onto the surface of a silicon wafer. room temperature type of gas phase photodeposition. the senior grad student took the custom built vacuum chamber i had the metal shop techs build for me in secret and did his dissertation on it. the professor who was paying my research assistant salary decided he needed it to finish. so i decided i did not wanna work for him anymore on the star wars laser project. except i needed money to live on.
long story, but one of the next projects with that laser was to work on making TiO2 using gas phase photodeposition from the hydride which can be put into the gas phase. but i quit grad school and joined the Dawn project group at H-P before i did that.
back in 1981 i did some experiments with an ultraviolet laser to photodeposit SiO2 onto the surface of a silicon wafer. room temperature type of gas phase photodeposition. the senior grad student took the custom built vacuum chamber i had the metal shop techs build for me in secret and did his dissertation on it. the professor who was paying my research assistant salary decided he needed it to finish. so i decided i did not wanna work for him anymore on the star wars laser project. except i needed money to live on.
long story, but one of the next projects with that laser was to work on making TiO2 using gas phase photodeposition from the hydride which can be put into the gas phase. but i quit grad school and joined the Dawn project group at H-P before i did that.
eTrike said:
Discussing point 1. If higher voltages are worse for the batteries, why would storing them at 50% instead of 20%, be better?
You see this is kind of one of the points of the video and why Nissan was brought up. Manufactures don't test them properly. The reason I believe manufacturers keep them at 50% has to do with self discharge safety of a bad cell going to 0% and the battery completely ruined. Manufacturers are more concerned about profit than what is best for the batteries.
Please show me any proof why storing them at 50% is the right voltage and now lower. This never made sense to me and I actually prefer to store them around 3.7.
Point 2, I agree it doesn't make sense that charging faster is better. Unless of course that while a cell is under discharge or charge, there is a lot of chemical reactions happening that only happen during a charge or discharge.
You could store them at 0% SOC, but then your allowable storage time would be 0 days due to self-discharge. When the manufacturer specifies a "storage" voltage, it's exactly that: A voltage suitable for being sat in a warehouse for extended periods. What you do at home is different you're free to choose whatever voltage you like.
I imagine the effects of storage at higher voltage (electrolyte decomposition), like the effects of temperature, are highly non-linear. So the advantage of going from 50% SOC to 40% SOC may be very small.
I imagine the effects of storage at higher voltage (electrolyte decomposition), like the effects of temperature, are highly non-linear. So the advantage of going from 50% SOC to 40% SOC may be very small.
ridethelightning
1 MW
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JackB
10 W
I agree that the point made was not to charge faster, but that heat kills the cell when charging/discharging.
But that implies faster charging is in fact better, as long as it doesn't create more heat, at 2c it probably does,
but at c/16 vs c/4 ? When its hot, do you recharge all day, and just 4 hours?
It implies to me 4 hours is better than taking 16 hours. The current thinking is slower is always better.
But that implies faster charging is in fact better, as long as it doesn't create more heat, at 2c it probably does,
but at c/16 vs c/4 ? When its hot, do you recharge all day, and just 4 hours?
It implies to me 4 hours is better than taking 16 hours. The current thinking is slower is always better.
Bison_69
100 W
Hi Guy,
I have watched this very interesting documentary... and I am really surprised, at the end of the video the host was saying to keep the batteries, when not used, as much as possible in a cold refrigerator to increase lifespan... (insted of room temperature like most of us are doing during winter)
Thank you for sharing...
I have watched this very interesting documentary... and I am really surprised, at the end of the video the host was saying to keep the batteries, when not used, as much as possible in a cold refrigerator to increase lifespan... (insted of room temperature like most of us are doing during winter)
Thank you for sharing...
liveforphysics
100 TW
Offroader said:
Many electronics will corrode and fail. Not from being stored in the freezer, but from the condensation that collects on and inside them when removed from a freezer into a warm room.
bowlofsalad
100 kW
This newish scientific method for battery measuring, coulumbic efficiency, is very exciting. It has made me wonder how rapidly things may be progressing after it's discovery to the point where I have held off buying higher energy density batteries for another year or two for my own electric bicycles.
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