LiFeP04 vs. LiMN vs. LiNiMnCoO2

[germanium]

About the lithium-manganese spinel batteries used in the Chevy Volt, They have already proven to be a safety hazard by errupting into flames 2 weeks after a crash test was done. Cause in this case was in fact determined to be the batteries. While it may be possable to create an unsafe condition for LiFePo4 batteries you have never heard of a true LiFePo4 powered hybrid car bursting into flames due to a battery malfunction where the battery itself ignites on its own after receiving abuse or been involved in a crash. That does not mean that there could not be a fire but it would not be caused by the battery itself igniting first. Fire could be caused by an electrical short which ignites the insulatin of the wiring due to the very high current capacity of LiFePo4 batteries but this is not the fault of the battery itself bursting into flames as it was with the Chevy Volt.

LiFePo4 still seemes to be the safest option & higher capacity is possable with this chemestry as proven by the LFP123 batteries from K2. These actually performed up to my expectation of what any lithium ion battery should have been capable of but till the K2 experiment I ran none lived up to as far as the CR123a battery size was concerned. All fell short by a substantial amount but not the K2's. The K2 LFP123 batteries do exchange current capacity for energy density though in this particular size. These are not the high current batteries that K2 makes in thier other sizes & are only rated for Cx2 for discharge rate. But under the circumstances I can see why they made that decision. Note that all the other K2 battery sizes are rated for greater than Cx2 discharge rates, even thier high energy versions as opposed to thier high power cells.

 

[cy]

jtr1962

I simply leave you with this point: if LiFePO4 were all it were cracked up to be then everyone would be using. In fact, the opposite is true. The early adopters (e.g. Black and Decker) are moving away from it, and no major US, Japanese or European car company is using or even considering using it.

If it works for you, then go for it. I stand by my original opinion that LiFePO4 is highly overrated and has only niche applications where it excels.

I also predict that A123 and other LiFePO4 based companies will fail in the next 5 years if one of the following two things does not happen:

1.) they move beyond LiFePO4 (it is not theoretically possible to improve its energy density beyond what it already is)
2.) a new, currently unknown, application is found that is perfect for LiFePO4-based lithium-ion cells

Government funding and investor patience is running out. LiFePO4 was an obsolete chemistry when it was developed (with all due respect to Goodenough and Hydro-Quebec), and it is still an obsolete chemistry.

That being said, my advice and opinions on this forum are free, and are probably worth slightly less than that.

Cheers,
BG

two years later .. looks like your prediction of A123 going out of business has come to pass. but you missed the beginning of LiFePO4 use for 12v motorcycle batteries, which dwarfs market size for electric car batteries.

weight savings of say 30-40lb means little to most folks unless you are part of a tiny group of light weight high performance cars like 911 owners. but saving 10 to 15lb on a motorcycle is HUGE!

yes there are LOTS of folks willing to spend say $225 to save 10lb+ on their high tech motorcycles. when compared to folks spending $$$ for carbon parts to save a few oz. vs dropping 10+lb in one stroke is a bargain.

the speed of adoption has caught a number of major battery mfg by surprise. competition is hotting up as more and more 12v LiFePO4 mfg hits the market place.

LiFePO4 is the only li-ion battery that drops in with NO modification to almost any 12v vehicle. ALL charging system designed to support 12v lead acid batteries mates perfectly with 12v LiFePO4 batteries.

LiCo's voltage of 4.2v max charge x 3 = 12.6v which puts cells in danger from overcharge and thermal runaway (explosion) 4.2v x 4 = 16.8v or too high for 12v motorcycle or automotive.

12v LiFePO4 reaches full charge at 14.6v, but quickly drops to 13.3v range at first discharge. then stays almost flat during discharge cycle. so effective operating range for 12v LiFePO4 is 13.3v (90%) to about 12.4v (10%) .. or a perfect match for all charging systems designed to support PB which puts out 13.8v to 14.2v range. some modern motorcycles operate slightly higher voltage.

gotta disagree with you assessment about LiFePO4 dangers being lower primarily due to lower energy densities. LiFePO4 discharges at HUGE amp rates and is inherently safe .. requiring wild abuse to catch on fire. I'm not aware of a single instance where LiFePO4 caught on fire in any vehicle where fire was not caused by a dead short. either internally and/or from dead short to positive from a wreck and/or poor installation. there's been many instances of LiFePO4 batteries melting from being charged at excessively high rates in excess of 7C.

vs there's a long history of LiCo cells going into thermal runaway (Boeing 787) with LOTS damage. including almost burning down homes. unless something has drastically changed, the biggest danger for LiCo occurs during charging.

 

[jtr1962]

I'll add that solar lighting seems to be another niche use where LiFePO4 is catching on big time. Anyone who has ever tried solar outdoor lighting has had issues due to battery failure. NiCd and NiMH just don't hold up in this type of use where they may be subject to overcharge, possible overdischarge, temperature extremes, and hundreds of cycles annually. A possible exception might be very robust cells like Eneloops but those are often too costly for this application. Moreover, the voltages of NiMH and NiCd are not well matched in this application. Boost circuits to drive the LEDs are required. Given the cost constraints, these are often quite inefficient. And the solar cells on many outdoor solar lights output ~3.6 volts. This is too high for 2 cells in series but too low for 3 cells. LiFePO4 on the other hand is a perfect match here. The 3.6 volts coming from the solar cells is perfect for charging with no possibility of overcharging. And the flat ~3.2V discharge curve is perfect to drive LEDs without any additional circuitry. Moreover, the energy density is superior to the NiCad batteries typically used in this application. Usually a pair of Nicads of about 700 mAh are used. This gives about 1.7 watt-hours but often 1/3 of this is lost in the boost circuit, delivering only 1.2 watt-hours to the LED. A typical LiFePO4 AA cell for this application is rated around 500 to 600 mAh. This means a stored energy of about 1.6 to 1.9 watt-hours, 100% of which is delivered to the LED. In short, one AA LiFePO4 cell replaces two AA NiCds and also eliminates the need for additional driver circuitry.

 

[cy]

I'll add that solar lighting seems to be another niche use where LiFePO4 is catching on big time. Anyone who has ever tried solar outdoor lighting has had issues due to battery failure. NiCd and NiMH just don't hold up in this type of use where they may be subject to overcharge, possible overdischarge, temperature extremes, and hundreds of cycles annually. A possible exception might be very robust cells like Eneloops but those are often too costly for this application. Moreover, the voltages of NiMH and NiCd are not well matched in this application. Boost circuits to drive the LEDs are required. Given the cost constraints, these are often quite inefficient. And the solar cells on many outdoor solar lights output ~3.6 volts. This is too high for 2 cells in series but too low for 3 cells. LiFePO4 on the other hand is a perfect match here. The 3.6 volts coming from the solar cells is perfect for charging with no possibility of overcharging. And the flat ~3.2V discharge curve is perfect to drive LEDs without any additional circuitry. Moreover, the energy density is superior to the NiCad batteries typically used in this application. Usually a pair of Nicads of about 700 mAh are used. This gives about 1.7 watt-hours but often 1/3 of this is lost in the boost circuit, delivering only 1.2 watt-hours to the LED. A typical LiFePO4 AA cell for this application is rated around 500 to 600 mAh. This means a stored energy of about 1.6 to 1.9 watt-hours, 100% of which is delivered to the LED. In short, one AA LiFePO4 cell replaces two AA NiCds and also eliminates the need for additional driver circuitry.

besides night and day differences in safety with LiFePO4 vs LiCo .. same thing could be said for number of charge/recharge cycles. provided LiFePO4 is not charged above 14.4v (14.6v 100%) and not discharged below 12.85 (20%) 2,000 to 5,000+ cycles is not unheard of.

besides safety and long life .. LiFePO4 multiples has the HUGE advantage of naturally mating up with LOTS of existing electronics. for instance .. ALL 12v charging systems designed to support PB. which happens to include almost every car/motorcycle made within last 25+ years .. will support LiFePO4 x4 in series = 14.6v full .. but that's misleading, the very first drain, voltage will drop to 13.3v (90%) .. then stay almost flat down to 12.4v (10%) .. this voltage profile fits 12v vehicles perfect!

ALL charging systems designed to support PB will put out 13.8v to 14.2v range ..with some modern motorcycles 14.4v range. again this fits perfect with 12v LiFePO4 max charge of 14.6v.

there are millions of 12v vehicles out there .. while it's not worth trouble of changing to LiFePO4 for most cars. fact is saving 30-40lb is just not that important.. unless you are amongst micro groups like 911 owners.

for the millions of 12v motorcycles out there .. saving 10-15lb is a very significant weight savings. speed of adoption for 12v LiFePO4 motorcycle batteries has surprised a number of battery mfgs. evidently there are LOTS of folks out there willing to spend say $225 to $300+ for a LiFePO4 battery to save 10lb to 15lb+ on their motorcycle.

then factor as AH capacity increases .. the density to weight ratio between LiFePO4 and LiCo starts to narrow... IMHO the future belongs to LiFePO4!!

then factor inherent safety of LiFePO4 due to chemical makeup. this mean LiFePO4 tolerates minor overcharge conditions without damage. during tests to destruction, it took wild abuse of charging 39v+ to catch 12v LiFePO4 on fire. it's very_difficult to cause a LiFePO4 battery to catch on fire, but it can be done.

most if not all documented fires from LiFePO4 failure has been traced to dead shorts internal or external from wrecks and/or bad installation. I've not been able to find a single documented instance of a 12v LiFePO4 catching on fire due to overcharge conditions. there's been all sorts of reports of 12v LiFePO4 melting from too high charge rates. from installing too small 12v LiFePO4.

 

[BVH]

I just received 12 each of the new Nissan Leaf 2S/2P, 7.6/60 AH LiMn2o4 modules. I haven't seen any definitive answer on the number of cycles these should have over their life. Most sites indicate about 500. I'm just wondering how Nissan, a large vehicle manufacturer that touts their Leaf so much, would use a battery chemistry yielding such a low life. It hardly seems that the pack would last 5 years before a serious reduction in capacity would occur, causing them issues down the road.

I'm using mine to power my large KW Short Arc lights away from an AC source and will never even put close to 250 cycles on them so it's not a big deal to me but I'm just wondering why Nissan would do this unless they project far more cycles.

 

[StorminMatt]

I just received 12 each of the new Nissan Leaf 2S/2P, 7.6/60 AH LiMn2o4 modules. I haven't seen any definitive answer on the number of cycles these should have over their life. Most sites indicate about 500. I'm just wondering how Nissan, a large vehicle manufacturer that touts their Leaf so much, would use a battery chemistry yielding such a low life. It hardly seems that the pack would last 5 years before a serious reduction in capacity would occur, causing them issues down the road.

I'm using mine to power my large KW Short Arc lights away from an AC source and will never even put close to 250 cycles on them so it's not a big deal to me but I'm just wondering why Nissan would do this unless they project far more cycles.

Hard to say about this one. I'm not sure whether Nissan is trying to get more cycles by charging and discharging them more conservatively. Or whether they are just taking a gamble. In either case, this could mean trouble for them. They could end up losing ALOT on premature warranty repairs OR end up hurting their reputation a good deal by trying to weasel their way out of replacing batteries with lower capacity. Only time will tell. Then again, the same goes for Tesla. They're using LiCo batteries. And, as anyone with a laptop or iPhone knows, they're not made to last. ESPECIALLY when, as is the case with Tesla, they are trying to maximize capacity. I know they are said to last quite a long time (I don't remember how long they said). But let's face it. Tesla is NOT in possession of a magic wand.

One more thing. With regards to the issue of EV vs ICE, I don't see EV's being better when it come to long term reliability than conventional ICE cars, at least as long as they are powered by Li-Ion batteries (with possibly the exception of LiFePO4, but even that's a maybe). Lots of people to this day are driving around 20+ year old Hondas and Toyotas, and they're still running strong. I myself have an old Civic that just refuses to quit. It doesn't miss a beat, passes smog, and still has good get up and go. Yes, I'm pretty diligent with such things as oil changes and timing belt replacements. But still, are any of today's EVs going to be around in a similar amount of time? Yes, such things as motors and controllers can run a REALLY long time. But if replacing a battery pack is going to cost several times more than replacing a conventional engine, I don't think longevity will be better with EVs. And for better longevity, one thing is clear. We need to move away from lithium.

 

[cy]

Hard to say about this one. I'm not sure whether Nissan is trying to get more cycles by charging and discharging them more conservatively. Or whether they are just taking a gamble. In either case, this could mean trouble for them. They could end up losing ALOT on premature warranty repairs OR end up hurting their reputation a good deal by trying to weasel their way out of replacing batteries with lower capacity. Only time will tell. Then again, the same goes for Tesla. They're using LiCo batteries. And, as anyone with a laptop or iPhone knows, they're not made to last. ESPECIALLY when, as is the case with Tesla, they are trying to maximize capacity. I know they are said to last quite a long time (I don't remember how long they said). But let's face it. Tesla is NOT in possession of a magic wand.

One more thing. With regards to the issue of EV vs ICE, I don't see EV's being better when it come to long term reliability than conventional ICE cars, at least as long as they are powered by Li-Ion batteries (with possibly the exception of LiFePO4, but even that's a maybe). Lots of people to this day are driving around 20+ year old Hondas and Toyotas, and they're still running strong. I myself have an old Civic that just refuses to quit. It doesn't miss a beat, passes smog, and still has good get up and go. Yes, I'm pretty diligent with such things as oil changes and timing belt replacements. But still, are any of today's EVs going to be around in a similar amount of time? Yes, such things as motors and controllers can run a REALLY long time. But if replacing a battery pack is going to cost several times more than replacing a conventional engine, I don't think longevity will be better with EVs. And for better longevity, one thing is clear. We need to move away from lithium.

gotta disagree .. LiFePo4 nicely solves the longevity factor at 5,000+ cycles .. drawback is energy density. which traditionally has been solved by numbers .. highest production cells gets the most R&D time combined with fastest time to market for competition reasons. delivering highest energy gives a competitive advantage.

don't assume vehicle mfg want the longest life possible. planned obsolesce in automotive is alive and well. drives long term profits. classical examples is ball joints, U-joints, wheel bearings .. all used to be serviceable parts that lasted virtually forever if serviced. auto mfg have long left off grease zerts and designed wheel bearing to be non-serviceable. forcing replacing entire rotor assembly with bearings impossible to service. etc. etc.

 

[KiwiMark]

two years later .. looks like your prediction of A123 going out of business has come to pass. but you missed the beginning of LiFePO4 use for 12v motorcycle batteries, which dwarfs market size for electric car batteries.

weight savings of say 30-40lb means little to most folks unless you are part of a tiny group of light weight high performance cars like 911 owners. but saving 10 to 15lb on a motorcycle is HUGE!

yes there are LOTS of folks willing to spend say $225 to save 10lb+ on their high tech motorcycles. when compared to folks spending $$$ for carbon parts to save a few oz. vs dropping 10+lb in one stroke is a bargain.

the speed of adoption has caught a number of major battery mfg by surprise. competition is hotting up as more and more 12v LiFePO4 mfg hits the market place.

LiFePO4 is the only li-ion battery that drops in with NO modification to almost any 12v vehicle. ALL charging system designed to support 12v lead acid batteries mates perfectly with 12v LiFePO4 batteries.

LiCo's voltage of 4.2v max charge x 3 = 12.6v which puts cells in danger from overcharge and thermal runaway (explosion) 4.2v x 4 = 16.8v or too high for 12v motorcycle or automotive.

12v LiFePO4 reaches full charge at 14.6v, but quickly drops to 13.3v range at first discharge. then stays almost flat during discharge cycle. so effective operating range for 12v LiFePO4 is 13.3v (90%) to about 12.4v (10%) .. or a perfect match for all charging systems designed to support PB which puts out 13.8v to 14.2v range. some modern motorcycles operate slightly higher voltage.

I've put one of those LiFePO4 batteries in my bike, saves around 7 pounds and it seems to work really well with good cranking speed when starting.
My bike is 15 years old (1998 Suzuki RF900R) and is having no problems with the battery.

One thing I'd like to point out - not only is there a weight saving but also the battery is fairly high up on the bike (just under the seat) so saving weight there lowers the centre of gravity, which is a good thing.

 

[cy]

I've put one of those LiFePO4 batteries in my bike, saves around 7 pounds and it seems to work really well with good cranking speed when starting.
My bike is 15 years old (1998 Suzuki RF900R) and is having no problems with the battery.

One thing I'd like to point out - not only is there a weight saving but also the battery is fairly high up on the bike (just under the seat) so saving weight there lowers the centre of gravity, which is a good thing.

which model LiFePO4 did you install? it's always good to get feedback no matter where found. most common reason for early 12v LiFePO4 failure is installing too small AH. most LiFePO4 mfg use extremely misleading AH numbers expressed in pb/eq .. where a 18AH pb/eq is actually 5AH capacity.

 

[KiwiMark]

which model LiFePO4 did you install? it's always good to get feedback no matter where found. most common reason for early 12v LiFePO4 failure is installing too small AH. most LiFePO4 mfg use extremely misleading AH numbers expressed in pb/eq .. where a 18AH pb/eq is actually 5AH capacity.

It is a LFX14A4-BS12, 14Ah equivalent.

 

[cy]

It is a LFX14A4-BS12, 14Ah equivalent.

1998 Suzuki RF900R should have about a 400 watt permanent magnet charging system. Shorai LFX14A4 weight is about 2lb .. so actual AH capacity is about 5AH.

labeling for 12v LiFePO4 has gotten so distorted that weight is one of the few metrics that's reliable to determine actual AH capacity. forget that pb/eq noise .. it means little to nothing.

a 5AH capacity LiFePO4 battery is way too small for a 900cc motorcycle. it may start just fine during moderate condition but will really struggle when temps dip down below 32f.

other factors to consider is max charge rate and parasitic drain. older bikes typically has lower parasitic drain rates. a tiny AH capacity doesn't last long sitting before battery is drained to dead and/or almost dead. LiFePO4 will still manage to turn over bike one time at 5% state of charge.

after bike starts with battery at 5% ... LiFePO4 is then in bulk charge mode and will swallow all the amps thrown at it. 405 watts / 14.2v = 29 amps less system overhead = 20 amp available to charge battery. 20amp / 5AH = 4C charge rate (C = AH) .. LiFePO4 cells typically don't like being charge over 4C

so with a 405 watt charging system .. a 5AH LiFePO4 will do just fine. but with bike with larger alternators like BMW R1200 with 720 watt .. less overhead = 37 amp / 5AH = 7C charge rate .. that will get a 5AH battery hot enough to melt.

 

[KiwiMark]

other factors to consider is max charge rate and parasitic drain. older bikes typically has lower parasitic drain rates.

I am sure that you are right about that, I've had the bike sit in the garage for a couple of weeks and then when I started it there was no noticeable loss of cranking speed from the starter. I have trouble thinking of anything on the bike that would drain power when it is off - it doesn't even have a clock.

My previous bike was a 2007 model Suzuki AN400 (good for city commuting) and it would have had some parasitic drain with the SACS (security system) and electronic dash with clock.

 

[tlb03]

Thanks to the intelligence of posters here...I'm learning.

I'm buying batteries for a solar configuration in the RV industry (say 200aH to 300aH units). This industry seems to lack understanding of battery chemistry and market trending. They all use LiFePO4 products and don't seem to understand the differences in Lithium choices. However, they are very good at installations. I'm looking at purchasing a battery from ebay that is listed as a "Lithium 12vdc 300ah 2.4kwh New 2015 VOLT battery Solar Off Grid Golf Cart". What I can't find out about this OEM product is the cycle life. The sales person doesn't know and is a tough character, funny, but a bit salty. The point is, he is not a help here. The price is less than half of the LiFePO4 products, so my interest is keen on the other product. The cathode material is listed as "LiMn2O4 with LiNiO2". I assume this is some type of Lithium Nickel Manganese product that I have read good results about. My understanding says this product is slightly less safe than the LiFePO4 product all things being equal but not "unsafe". My biggest question is trying to figure out the cycle life of this product. I can't find info anywhere and don't know how big a deal this might be to my buying choice. I'm not technically proficient here, but I do want to make a sound and wise purchase. These things are expensive!

 

[Gauss163]

Those packs are recycled from electric cars - the Chevy Volt in the case you mention. Search on that and you will find much more.

 

[tlb03]

Those packs are recycled from electric cars - the Chevy Volt in the case you mention. Search on that and you will find much more.

The seller states they are new direct from GM who assembles the packs that come first from LG Chem in Japan. He has a 100% ebay rating from 749 users, so I suspect he is a truth teller, although as I stated a bit salty. I will search on that because that's also an option I should look at. Thanks for the suggestion.

 

[Gauss163]

Be careful with eBay feedback. Even sellers of "10000mAh" 18650s receive almost all positive feedback on them. The general public is not a trustworthy source of wise reviews.

 

[tlb03]

Be careful with eBay feedback. Even sellers of "10000mAh" 18650s receive almost all positive feedback on them. The general public is not a trustworthy source of wise reviews.

Wise precaution, thank you!

 

[Peter A]

jtr1962

I simply leave you with this point: if LiFePO4 were all it were cracked up to be then everyone would be using. In fact, the opposite is true. The early adopters (e.g. Black and Decker) are moving away from it, and no major US, Japanese or European car company is using or even considering using it.

If it works for you, then go for it. I stand by my original opinion that LiFePO4 is highly overrated and has only niche applications where it excels.

I also predict that A123 and other LiFePO4 based companies will fail in the next 5 years if one of the following two things does not happen:

1.) they move beyond LiFePO4 (it is not theoretically possible to improve its energy density beyond what it already is)
2.) a new, currently unknown, application is found that is perfect for LiFePO4-based lithium-ion cells

Government funding and investor patience is running out. LiFePO4 was an obsolete chemistry when it was developed (with all due respect to Goodenough and Hydro-Quebec), and it is still an obsolete chemistry.

That being said, my advice and opinions on this forum are free, and are probably worth slightly less than that.

Cheers,
BG

B&D and others moved from LiFePO4 because of cost, not performance. The 18650 market became commoditized and A123 couldn't compete even with their Chinese plant. Your prediction about A123 did come true, but that was more about betting too hard on the automotive market too early. Now all of us are spread across the industry.