Lifepo4 nano technologies

abhi555

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Some years back A123 brand was purchased by a Chinese company. Does anyone know what happened to these or similar lifepo4 nanotech batteries?
Are these batteries not leading/getting used anywhere because of lower energy density? just curious
 

vicv

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Mar 22, 2013
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Southern Ontario
Ya it seems unfortunately that lifepo4 just stopped getting R&D. They had a lot of potential. Honestly though not much overall use to us flashaholics. The voltage isn't high enough for LEDs and didn't match up right for most incan uses either. Of course with the newer, lower vf LEDs, they could work.
The company who took A123 systems over is called Lithium Werks
 

jtr1962

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Flushing, NY
Apparently there was still enough R&D to get the capacity up. A123 26650s started at 2300 mAh, then they went to 2500 mAh. Now there are some generic 26650 cells rated at 3800 mAh. I think that's getting close to maximum theoretical energy density. Low 4000s might be the most these can reach.

LiFePO4 is still being used in lots of stationary applications where safety and longevity matters more than energy density.
 

aznsx

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<<<LiFePO4 is still being used in lots of stationary applications where safety and longevity matters more than energy density.>>>

And serving well in several of my 1xCR123A lights which are not 16340 (most chemistries [3.6/7V]) compatible. Using K2 Energy.
 
Last edited:

Stabile

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Feb 22, 2017
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Some years back A123 brand was purchased by a Chinese company. Does anyone know what happened to these or similar lifepo4 nanotech batteries?
Are these batteries not leading/getting used anywhere because of lower energy density? just curious
I‘ve used a fair number of LiFePO4 cells over the last several years - they don’t have the highest energy density, but there are a number of advantages to them, depending on what you want to do.

For example, they’re a lot happier with cold environments, willing to survive most winters if you monitor temps and limit or stop charge/discharge cycles. They’re willing to take a lot of physical torture without danger of exploding or catch ‘a fire, and the disposal is a lot more forgiving than most other Li chemistries.

The normal range of terminal voltages isn’t really a problem; very few serious difficulties exist that depend on LED threshold voltages, which shouldn’t be the determinant, anyway. These things are current driven, even if you ‘see’ your excitation as ’applying a voltage’ that’s not what’s happening with the device physics in circuit.

I imagine the primary barrier to LiFePO4 use in simple flashlight circuits would be about voltage, but this is reflected in the chip(sets) commonly available, the preset versions of which tend to address more common chemistries, which, as mentioned, provide a whole different set of charge/discharge and protection parameters.

None of that is a problem, of course, if you design for the chemistry of choice from the bottom up. Any reasonably efficient design is likely to be high-freq switcher based, and the analog thresholds in protection/management circuitry are most often set by simple resistor ratios.

From what I’m seeing (and buying) lately the predominant design trope seems to be ultra low power microprocessor based, at least in the IP of the digital logic part of the puzzle, and such things will want to work on voltages well within the terminal voltages of almost any chemistry.

The rest is just the standard design effort, and that’s the fun, yes? For me, the cool thing about the world of flashlights is the game of seeing how slick current technology can make one, size, power, beam style, the whole thing. It’s a tiny design context that almost anyone can fool around in with some success, but it reflects the bigger current engineering world in a nice way.

—TR
 

aznsx

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I‘ve used a fair number of LiFePO4 cells over the last several years - they don’t have the highest energy density, but there are a number of advantages to them, depending on what you want to do.

For example, they’re a lot happier with cold environments, willing to survive most winters if you monitor temps and limit or stop charge/discharge cycles. They’re willing to take a lot of physical torture without danger of exploding or catch ‘a fire, and the disposal is a lot more forgiving than most other Li chemistries.

The normal range of terminal voltages isn’t really a problem; very few serious difficulties exist that depend on LED threshold voltages, which shouldn’t be the determinant, anyway. These things are current driven, even if you ‘see’ your excitation as ’applying a voltage’ that’s not what’s happening with the device physics in circuit.

I imagine the primary barrier to LiFePO4 use in simple flashlight circuits would be about voltage, but this is reflected in the chip(sets) commonly available, the preset versions of which tend to address more common chemistries, which, as mentioned, provide a whole different set of charge/discharge and protection parameters.

None of that is a problem, of course, if you design for the chemistry of choice from the bottom up. Any reasonably efficient design is likely to be high-freq switcher based, and the analog thresholds in protection/management circuitry are most often set by simple resistor ratios.

From what I’m seeing (and buying) lately the predominant design trope seems to be ultra low power microprocessor based, at least in the IP of the digital logic part of the puzzle, and such things will want to work on voltages well within the terminal voltages of almost any chemistry.

The rest is just the standard design effort, and that’s the fun, yes? For me, the cool thing about the world of flashlights is the game of seeing how slick current technology can make one, size, power, beam style, the whole thing. It’s a tiny design context that almost anyone can fool around in with some success, but it reflects the bigger current engineering world in a nice way.

—TR

Interesting perspective. Thanks for posting it. It got me thinking, which is always dangerous, but also good for me, and yes, fun!
 

Sphinx99

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Jan 29, 2021
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LFP has achieved a nearly 100% increase in energy density over the last ~decade, largely on the strength of heavy automotive LFP R&D investment in China by companies like CATL and BYD. The net result is that modern LFP chemistries come within ~20% of nickel oxide cells but with greater rate capability and cycle life and a lower cost floor as well as superior abuse tolerance. All the tricks being explored with nickel/cobalt chemistries are also being investigated with LFP - higher voltage electrolytes, graphite -> silicon, etc.

I haven’t seen any of this make its way to consumer applications because, well, consumer electronics energy storage is actually not terribly cost sensitive - manufacturers will happy pay an extra dollar or two for more energy density in a smart phone. And, since LFP from a physics perspective will never match nickel oxide, there isn’t much motivation to explore it. In large format industrial, commercial and automotive applications, it’s a completely different story - the cost, safety and life advantages are paramount and LFP is all but the deaf to leader-to-be over the next decade.
 
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