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Power Hardware Science

Degraded Electrodes Observed In Aging Batteries 108

Posted by timothy
from the taking-away-all-the-mystery dept.
schliz writes "Scientists have identified nanoscale changes in aging lithium-ion batteries that could be responsible for their degradation over time. By dissecting and examining dead batteries, they found that some lithium was irreversibly lost from the positive to negative electrode of dead batteries, and no longer participated in charging and discharging. They discovered that finely-structured nanomaterials on dead batteries' electrodes had coarsened in size, and theorise that the coarsening of the cathode may be responsible for the loss of lithium."
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Degraded Electrodes Observed In Aging Batteries

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  • I thought that's the way they were engineered - to generate revenue by way of having to replace them annually.

    • I have a thirteen year battery that still gives over a hour and a half of service. The number of cycles is everything. If you deep cycle it every day, you won't get two years out of it.

      • Really ? I thought it was exactly the opposite.
        • by beelsebob (529313) on Wednesday October 20, 2010 @08:18AM (#33959910)

          Modern lithium polymer batteries survive best if you keep cycling them regularly, but *not* deep cycling them. Regularly discharging to 30-70%, and then charging again keeps them nice and healthy. Running them down to 0% all the time drives charge backwards through some cells, and helps cause early death.

          • Re: (Score:2, Informative)

            >>>Regularly discharging to 30-70%, and then charging again keeps them nice and healthy.

            I like to use a dog analogy. If you feed your dog until he's overweight, then don't feed him until he's skeletal, and then feed him again til he's overweight, then don't feed until he's skeletal... your dog won't live long. The stress will shorten his life. ----- The same is true for batteries. Overcharging and then draining them to empty stresses the cell. The ideal is to hold the battery between 60% and 90%

        • Nickel Cadmium (NiCd) works as you expect. Those batteries are old technology, but they are still used in some cordless power tools and certain other applications. Unless you let them fully run down, the develop "memory" and refuse to run out a normal cycle. The memory issue does not apply to NiMH and Lithium Ion, but each of those technologies has its own limitations.

          Lithium Ion is gradually replacing NiCd in power tools. But there are issues such as the temperature extremes and high current loads tha

          • by rsborg (111459)

            NiMH prefers what NiCd hates: a partial charge/discharge. I am told the NiMH batteries in a Toyota Prius are charged only to 55% of capacity, and allowed to run down only to 45% before charging begins. The car carries 10x as much battery capacity as it actually uses, supposedly to maximize battery life. I don't know for sure if it works that way, but that's what I heard.

            Close, it's about a 45-75% [howstuffworks.com] range:

            To get maximum life out of the Prius battery pack, the car's computer brain does not allow the battery to

          • And then there's NiFe, which does not give a damn.
    • Re: (Score:3, Interesting)

      by sakdoctor (1087155)

      We've come a long way since replacement batteries that cost as much as the laptop/phone did in the first place.

      Order some generic cells and get soldering.

      • Re: (Score:3, Insightful)

        by Lord Byron II (671689)

        Apparently, you've never owned an Apple product.

        • Re: (Score:3, Funny)

          by Anonymous Coward

          We don't count Apple products in the realms of Progress.

          • Apparently replacement batteries are indeed available for Apple handheld devices. The trick is to get them open, but kits are available. As for replacing the battery in your MacBook, though, I wouldn't have a clue.
        • Re: (Score:3, Insightful)

          by sakdoctor (1087155)

          Do I need to remind you that you have a choice in what products you buy?

          Buy something that is open/hackable/geek friendly.
          Buy batteries that can be rebuilt by the user using only a screw driver and soldering iron.
          Buy laser printers that have a toner refill port.
          Buy routers that can be reflashed with your choice of firmware.

          Who gives a FUCK about apple. Why does /. even have an apple section?

      • by mcgrew (92797) *

        I don't know, I paid $20 for an IBM thinkpad with a bad battery and bad hard drive. Replacing the battery would cost half as much as I paid for my Acer netbook last April.

        Of course, the Thinkpad was probably a couple grand when it was new.

    • Re: (Score:1, Funny)

      by Anonymous Coward

      I read it as

      Deranged Electrodes Observed In Aging Batteries

      I guess that's what happens when you get older and are bipolar.

    • Re: (Score:3, Informative)

      by cgenman (325138)

      I just found a power setting on my new Ideapad that keeps the maximum charge at %80. You lose 1/5th of the runtime in the short term, but you should be able to get a much longer total runtime over time out of it, especially if you keep it plugged in. Thank you, Lenovo.

      Which brings to my next point: DON"T KEEP YOUR LAPTOP PLUGGED IN. Charge it, then unplug. The battery will last much longer if you continually cycle it, rather than if you try to keep it topped off all of the time. I've toasted batteries

      • Re: (Score:1, Informative)

        by Anonymous Coward

        If you want to keep your laptop plugged in (say if you use it as a desktop replacement), take out the battery.

        I am using the first (original) battery that came with it, it's still good enough to give me about 20 minutes worth of power so in case of a power outage there's enough time to finish what I am doing, saving my work, and gracefully power down the system (unless the power came back up, of course).

        I bought an aftermarket regular and an extended capacity battery for less than an original Sony battery w

        • by StikyPad (445176)

          Some laptops won't run with the battery removed, and some batteries can't be removed (easily).

          Nonetheless, you can't have it both ways. Either you get a topped off battery that's ready when you need it (at the cost of slightly diminishing the life of the battery each day), or you have a disconnected battery that will self-discharge even if it's not in use. As you say, if it's 100% a desktop replacement, then removing the battery is worth a shot, provided you remember to re-insert it and allow it to charge

  • Every decade they find some keyword and the slap it on everything in sight. In the past they have indiscriminately slapped "motor" "radio" "jet" "aero" "bio" "e-" ... Now it is "nano".

    Gimme a break. These batteries are based on electro-chemistry. You know, interactions between molecules. Everything that goes on in batteries, all batteries, are nanoscale, by definition. Corrosion in the electrodes had been known and studied for ages. It is a damn chemical reaction that will happen at molecular level.

    • by Lord Byron II (671689) on Wednesday October 20, 2010 @07:25AM (#33959448)

      Sure, the net effect is at the macro-scale. But we now have the ability to look at these systems at the nano-scale and investigate why the "damn chemical reaction" gets going in the first place. "Nano" here says more about the equipment used to look at the battery than the battery itself.

      • Electrochemists everywhere have known why the 'damn chemical reaction' gets going for many decades, and equipment that allows study at 'nano' scales has been around for quite a while now also, even though it continues to get better. I see no basis to criticize these researchers, since there was almost no information of substance in the article. But I have to agree with the grandparent: if you want to get your research funded, or want people to read your article, be sure to scatter the word nano around.

        • Fuck you, buzzword hating bitch. Be warned, in 2030 you may well find yourself left-behind after the Singularity rapture.

          Nanobots are the way and the life. If you don't believe in them, may your puny brain turn to goo.

      • Re: (Score:3, Funny)

        by Rogerborg (306625)
        Yeah, I wish I'd had one of those fancy-pants "nanoscopes" to look at slides of fly wings and flower pollen when I was a lad - we had to make do with primitive "microscopes".
        • by sconeu (64226)

          Nanoscope? Ha! I'm waiting to get my picoscope!

        • by StikyPad (445176)

          Pfft, nanoscopes. Anyone not using a femtoscope might as well just turn in their nerd card now.

    • Absolutely. And considering that distances at that level are what? 10^-19? That is a gagaillionth.

      So, this is really happening on the gaga scale.

      Cue the bleach blond in the bikini!

    • by jeffb (2.718) (1189693) on Wednesday October 20, 2010 @07:37AM (#33959532)

      Really? You're complaining about using the term "nano" to refer to structures bigger than molecules but smaller than the wavelength of light?

      By the same token, everything that goes on in your body is based on bio-chemistry, and therefore "nanoscale by definition". But it's still useful to distinguish (for example) biochemical changes in bone digestion due to biphosphonates from microscopic changes in bone structure associated with osteoporosis from large-scale changes associated with being run over by a truck.

      The nanoscale structure of battery electrodes, larger than individual molecules but smaller than the wavelength of visible light, is absolutely critical to optimizing battery performance. It's distinct from the battery's basic chemistry, it's distinct from gross electrode shape and size, and it's certainly distinct from the macroscopic and chemical changes "studied for ages" in association with corrosion.

    • Re: (Score:3, Insightful)

      by shadowofwind (1209890)

      Some others...hi-fi, cyber, eco....

      Other words are also used for their positive or negative connotation, stripped of other meaning. An example that comes to mind is when people say that something rocks. A song, a radio station, a musician, or a band can rock. Nothing else can rock, sorry.

      I've noticed that many people with "good" language skills wield words easily because that's how they think. When they hear a new phrase they get some sense of its meaning, and subsequently use it where it seems to be ap

      • by jbengt (874751)

        A song, a radio station, a musician, or a band can rock. Nothing else can rock, sorry.

        So when I sit on that chair on my porch I'm, what, tipping back and forth? But not rocking?
        More on point, anything that gets you up and moving can rock, even if it is not music.
        Besides, rock and roll originally [etymonline.com] had a meaning before being applied to music: among other things, it refered to movements associated with sex.

        rock (v.1)
        "to sway," late O.E. roccian, related to O.N. rykkja "to pull, tear, move," Swed. rycka "to pull, pluck," M.Du. rucken, O.H.G. rucchan, Ger. rücken "to move jerkily." For musical senses, see rock (v.2). Rocking horse is first recorded 1724; rocking chair is from 1766. To rock the boat is attested from 1931. Rock-a-bye first recorded 1805 in nursery rhyme. rock (v.2)
        "to dance to popular music with a strong beat," 1948 (first attested in song title "We're gonna rock"), from rock (v.1), in earlier blues slang sense of "to cause to move with musical rhythm" (1922); often used at first with sexual overtones (cf. 1922 song title "My Man Rocks Me (with One Steady Roll)"). Sense developed early 1950s to "play or dance to rock and roll music." Noun sense of "musical rhythm characterized by a strong beat" is from 1946, in blues slang. Rock star attested by 1966. Rocksteady, Jamaican pop music style (precursor of reggae), is attested from 1969.

        • I almost added a few sentences on the sex angle, and how that does and doesn't relate to what I'm talking about, but decided it wasn't worth the effort.

          Thanks for the rocking chair meaning of the word 'rock' though, I wasn't aware of that one.

    • by hey! (33014)

      Indeed. I hate progress in anything other than technology as much as anyone else, but it is just barely possible that "nanoscale" is a reasonable term to use here. They are talking about very small physical changes in the electrode as Lithium atoms migrate away from it.

      AFAIK, there's not official definition of "nanoscale", but I understand it usually refers to measurements between 1 and 100nm. It seems reasonable to apply the term to any kind of thing that is convenient to describe in nm (e.g., anything

    • Re: (Score:3, Insightful)

      by russotto (537200)

      Gimme a break. These batteries are based on electro-chemistry. You know, interactions between molecules. Everything that goes on in batteries, all batteries, are nanoscale, by definition. Corrosion in the electrodes had been known and studied for ages. It is a damn chemical reaction that will happen at molecular level.

      They're not talking about the chemistry, though. They're talking about structural changes. So while the "nano" may be annoying, it's appropriate. Still, this doesn't sound any different th

      • by Tisha_AH (600987)

        The same problem applies to electroplating operations. If your electrolyte bath is not in perfect condition, if temperatures are not right, if the current is too high, etc... you will get a bad plating finish.

        Batteries (lead, lithium, nickel-cadmium, carbon-zinc) all have the same problem. A certain percentage of the metals end up in a state that is useless for battery operation. This should not be a big surprise to anyone who understands the chemical processes.

    • by tlhIngan (30335)

      Gimme a break. These batteries are based on electro-chemistry. You know, interactions between molecules. Everything that goes on in batteries, all batteries, are nanoscale, by definition. Corrosion in the electrodes had been known and studied for ages. It is a damn chemical reaction that will happen at molecular level.

      Except, we don't know why lithium-ion batteries age. That is, even if you treat them well, they'll eventually die out anywhere from 1-5 years. The clock starts ticking the moment they're manuf

    • You forgot to mention the suffixes marketing people love to slap on stuff. Slapping "-o-matic" on the end of everything from the 50's comes to mind right away.
  • by pinkeen (1804300)
    "Things degrade and break over time, especially if you use them."
    How this is news ? WTF?
    • Re:WTF? (Score:4, Interesting)

      by vlm (69642) on Wednesday October 20, 2010 @07:48AM (#33959626)

      "Things degrade and break over time, especially if you use them."
      How this is news ? WTF?

      The article carefully avoided mentioning that the scale of the damage was not known before. In my limited chemistry knowledge I always assumed the problem was the electrodes either went into solution or gained a molecule thick film of icky-stuff that prevented the reactions.

      Its bad news... If you're trying to prevent dissolving, well, thats a very well known problem and you can play games with buffer solutions and making the electrodes more or less insoluable, and all kinds of other ideas. Old tech "no problemo". Or if the problem was thin film growth, basically electroplating gone wild, thats also old tech "no problemo" with chleating agents and electropositive series and decades/centuries of metallurgical corrosion research. By old tech, no problemo, I mean its a well developed area of study, not "the great unknown", or not that the solution inevitably exists or is cheap, just that the research is likely to proceed quickly and efficiently. But what is a non-mechanical engineering solution to surface roughness getting screwed up chemically? Hmm. At this time of morning, I have no idea what the next step could be. Lots of blue sky research money getting spent, I'd guess.

    • by Dunbal (464142) *

      Slashdot has just discovered entropy, apparently.

  • How about equipping devices with a small solar cell that can act as a charger in emergencies? Might be a good idea when the LIon no longer roars.
    • by drinkypoo (153816)

      A small solar cell isn't going to do shit, and whenever you're not using it, it's just a waste. Leaving batteries in the sun is a recipe for failure, so leaving battery-powered devices in the sun is the same. (Most of those solar battery chargers are fucking lame just for this reason, including ALL candybar chargers.)

      If you want a small solar charger, carry it separately. You can get one with LiIon batteries in it from SlaveryExtreme for about $13.

      • Re: (Score:2, Funny)

        by isama (1537121)
        I woudn't google SlaveryExtreme if I were you.
        • Re: (Score:1, Informative)

          by drinkypoo (153816)

          I woudn't google SlaveryExtreme if I were you.

          If people don't know what DealExtreme is, or if people don't know that all this $2.99 shit coming out of China is built with slave labor, or can't put these two facts together, then they probably don't need to be buying any cheap chinese shit anyway.

      • by CAIMLAS (41445)

        It has pretty decent implications for vehicles. Even with a lead-acid battery, a small amp positive trickle charge will go a long way to making your battery last longer before it's in need of replacement.

        • It has pretty decent implications for vehicles. Even with a lead-acid battery, a small amp positive trickle charge will go a long way to making your battery last longer before it's in need of replacement.

          Yeah, I have a Coleman solar charger that plugs into the cigarette lighter in the dash. It's about 10cm wide and 40-50cm long.

          During the winter months when I don't go anywhere for a week or two at a time, it's the difference between a dead battery and one that will still start the car after two weeks.
    • by ledow (319597)

      Because 90% of electronics can't run anything off the power supplied from a solar cell. Solar stuff is still inside the calculator / overnight trickle charger range of power.

      Hell, it can take 8-10 hours to charge some AA's in some (not entirely dark) countries. If I have one as big as a folded out suitcase, I might *JUST* be able to get enough juice to start my car once if I leave it in direct sunlight for a few hours / days.

      Seriously, your average laptop can pull 90W during booting (19V 4.5A isn't unusua

      • by gabebear (251933)
        Sticking solar panels on things you put in your bag/pocket is dumb, but solar does work well. You can pretty easily carry 50W+ of solar cells, which is enough to run most any laptop (you still need a charging circuit and a small battery as a buffer). http://www.katerno.com/detail.php?s=92637 [katerno.com]

        One place where solar panels should be, and aren't, is on hybrid cars. As far as I can tell, they aren't included mainly because of laws mandating that cars meet gas-type requirements(i.e. the US version of the Prius
      • Re: (Score:1, Insightful)

        by Anonymous Coward

        You should probably be quiet. If you think solar power is good for overnight trickle charging, you don't understand the technology.

      • "When it hits reasonable amounts of power, then you can begin to even think about anything like that."

        I'm not looking foward for the time the Sun turns into a red giant... Now, solar isn't shit. It is just not suitable to be used as a portable power source.

  • This is some just really old news. Papers have been published on this and the other myriad sources of lithium battery degradation over the last several decades. In fact, this sort of coarsening, irreversibility, and poisoning are common in all such "nano" and even "micro" systems in which thermodynamics and kinetics are pitted against each other. For instance, at a three day international workshop on automotive lithium batteries half a decade ago, about a third of the talks were on various degradation me
    • by vbraga (228124)

      The paper is on Scripta Materilia, Volume 60, Issue 11, Pages 933-936 (why don't know why but I'm not able to copy and paste while using Chrome). It's available on ScienceDirect. It's over a year old and I don't know if there's any newer paper on the same subject by this group of authors.

      The usage of AFM/SSRM to make this kind of consideration is pretty new, at least for me but this is not my field, besides being also a materials scientist. The paper is interesting but I would like to see more quantitative

  • What are the implications for EVs, which seem to primarily use Li based batteries?

    I know the 'record' for these batteries is pretty good so far (not bad enough to make Consumer Reports respond yet, at least), but I have to wonder how much of that is due to ideal environmental factors and how much of it is due to the things not being out long enough, or used enough, to get an accurate measure. How are the first generations of the Prius doing? I've yet to see any reviews or analysis. This is important for the

  • by jones_supa (887896) on Wednesday October 20, 2010 @10:43AM (#33961704)

    People usually have many opinions on how you should use laptop or phone batteries to maintain maximum longevity. Keep it plugged in always when possible, discharge it to 50% every now and then, or always run it from full to empty, etc.

    It would be cool if we had some "battery mythbusters" who would systematically test these things with different machines and usage patterns so we could get more solid data on the subject. :)

    • Yep. Subjects for them to test:
      -Different regimes on NiMH, NiCd, Li-ion, LiPoly, LiFePO4 and lead-acid.
      -Pulse charging
      -Those "battery desulfators"
      -Charge up some alkalines to show it's possible
  • News flash! Old stuff wears out and doesn't work as well!

    Next up: A study on why my 20-year-old car isn't working like its brand new anymore.

Nothing will dispel enthusiasm like a small admission fee. -- Kim Hubbard

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