back to article Aluminum bendy battery is boffins' answer to exploding Li-ion menace

Stanford University eggheads have revealed a prototype aluminum battery that's apparently rechargeable, flexible and cheap, and could replace lithium-ion and alkaline batteries. New aluminium-ion battery from Stanford "We have developed a rechargeable aluminum battery that may replace existing storage devices, such as …

  1. Arctic fox
    Thumb Up

    For once the news on the battery front may actually lead to something.

    "In the short term, the team hopes the aluminum batteries could be used to replace the alkaline batteries poisoning landfills around the globe. These typically put out 1.5 volts, something the aluminum prototype can easily manage, but lithium-ion are a tougher proposition"

    Even if the shortfall in voltage compared with Li-ion batteries proves a tough nut to crack the replacement of alkaline batteries would be a major step forward.

    1. Cliff

      Re: For once the news on the battery front may actually lead to something.

      Yes, this is actually rather exciting.

      Just hoping it can also work for weight, endurance, self-discharge etc as it could be such a boon.

    2. Lusty

      Re: For once the news on the battery front may actually lead to something.

      "Even if the shortfall in voltage compared with Li-ion batteries proves a tough nut to crack"

      At this point it may be easier to change the requirement for higher voltage. Chip voltages have been dropping gradually, and seem only to be as high as they are for legacy reasons a lot of the time. I think it was Google who pioneered the idea of removing all but the 5v connection from power supplies which increased efficiency compared to the old multi voltage ones. I wouldn't be surprised if it's just the screen backlight that needs higher voltage these days to avoid the wires overheating with current.

    3. Lee D Silver badge

      Re: For once the news on the battery front may actually lead to something.

      Virtually every news item I've ever seen about batteries in the last ten years came to nothing. If I believed half the claims, we should have super-capacitor-like batteries that last for years on a single charge of a few seconds.

      Notice the critical point - not the voltage (typical battery cells were only 1v or so for decades anyway, serialising them produces the voltage you want!), or the flexibility, or the non-catchy-fire-ness. The energy density can't compete, which is why it's barely mentioned. So while it's a nice research project, it's nowhere near commercial.

      Have you SEEN the energy density of a Duracell AA? You get over an Ah in a AA package. You can go to 2 or 3 Ah in the same space with non-alkaline quite easily. This is what you're competing with, at the "low end" of the consumer market. Li-ion is nearly twice that.

      And a AA battery has something like FIVE times the energy density of a lead-acid battery. To get into the low end, the energy density has to get close to lead-acid at least to be viable. The fact that they haven't said that it is close to that, means it probably isn't.

      To compare against AA's and NOT against lead-acid means they have some fatal flaw. It doesn't scale, or it heats up immensely, or some other problems with larger mass or that it can't compete against lead-acid with.

      But, to be honest, it's all hogwash until they can make a set of AA batteries and test them. The format of the battery determines the energy density that's practically possible more than anything else. Some things just can't go that small, can't layer like that, etc. And then the killer is really cost. If it's not commercially viable to make ONE AA battery from the technology at the moment, it'll be decades before you see it in shops, if you ever do.

      I love science, etc. but getting at all excited about battery technologies is just bound to lead to disappointment. You won't be seeing these any time soon. And there are a THOUSAND competing products doing the same. They make nice research projects, which last precisely until the research students get their PhD. And then they die a death.

      1. Paul Shirley

        Re: For once the news on the battery front may actually lead to something.

        @Lee D: all true for portable uses but you ignore the mention of grid storage. High energy density is less important than not blowing up/burning easily, long lifetime and low cost. A stack of these sitting in garages or cupboards soaking up PV panel output would pretty much solve the intermittency problem. Could go a long way to fixing it in wind power, which aren't short of space to pile up batteries.

        This isn't a replacement for lithium cells, more suitable for displacing lead acid. You wouldn't put them in your car but might put them in the garage to charge that car.

        1. Anonymous Coward
          Anonymous Coward

          Re: For once the news on the battery front may actually lead to something.

          "A stack of these sitting in garages or cupboards soaking up PV panel output would pretty much solve the intermittency problem."

          Fine for off grid applications where cost and space are not a problem. But here in the UK solar isn't cost effective without ridiculous subsidies (14.38 p/kWh, for output that on wholesale markest would be worth about 3p/kWh on average). If you then add in storage that has a not insignificant cost - I've been working on future cost projections for grid storage, and even allowing sustained double digit annual price falls, storage doesn't wash its face. You've then got extra control gear and complexity for the storage, which is more cost over and above the storage itself. You've got the floor space occupied, which might seem irrelevant, but it's still taking up an area of the property, which at build cost is typically around £800/sq m.

          And if you're still requiring the grid as your back up, who pays the fixed costs of the networks, systems, and central generation? Under current arrangements where most of the costs are boiled down to a bogus marginal price, the PV+storage enthusiast would not result in any reduction of system costs, but at marginal pricing they'd be charged to those without this options - ie those in high density housing including flats and apartments.

          Maybe that suits you, but it becomes a dramatic extension of the current dystopian subsidy regime, in which wealthy middle class types have their energy bills subsidised by everybody else (ie, weighted towards the less well off).

          The sooner DECC is stopped from its idiotic wanking around with vast market distorting subsidies the better. If people want to install PV at wholesale market rates of circa 3p, then they're welcome, but I don't want to support the bastards.

          1. Anonymous Coward
            Anonymous Coward

            Re: For once the news on the battery front may actually lead to something.

            How do your projections go for the cost of power when you need more power stations?

            I haven't done the numbers but if you consider that subsidies could prevent needing to build new power stations they might be a good investment

            1. Anonymous Coward
              Anonymous Coward

              Re: For once the news on the battery front may actually lead to something.

              "I haven't done the numbers but if you consider that subsidies could prevent needing to build new power stations they might be a good investment"

              Evidently you haven't done the numbers. But I work with those who have done the numbers. Renewables (subsidised or not) only avoid the need for fossil fuel plants if they can deliver with total reliability at times of peak demand. If that's Arizona, where peak demand is during hot sunny summer days due to air conditioning, then it can work. But in the UK, where peak demand is on the coldest, stillest winter evenings, then renewables and any credible storage technology simply can't cut it, because there is no scenario under which you could capture sufficient power from renewable sources when it is available. Even if you overcame that by putting PV on every building roof in the UK and putting a wind turbine in every field, you've still got to store the power for months on end, and in volumes sufficient to power the UK through (eg) the very cold, calm winter conditions that prevailed in 2010-2011, for say three continuous weeks.

              If in your world of renewables plus storage on any single day you can't meet demand, then you either face up to power cuts in the worse conditions, or you're back to having centralised fossil or nuclear back up, and you still need the grid at the same size (or with greater capacity) to do what you'd like. So the underlying fixed costs remain the same or greater, before you've added storage and further build out of renewables.

              To date, UK energy policy has frittered the fat end of £40bn on "renewables", and at this particular instant that £40bn is generating less than 2% of total midday demand on a mild spring day. Even at EDF's farcical pricing for Hinkley Point C, the same money spent on nuclear would have delivered just short of 10GW of reliable capacity, or about 30% of today's midday demand. And you want more subsidies, and more money spent just to store renewable power?

        2. Stuart21551

          Re: For once the news on the battery front may actually lead to something.

          Especially if they can discharge that quickly.

      2. Lusty

        Re: For once the news on the battery front may actually lead to something.

        "Have you SEEN the energy density of a Duracell AA?"

        Funny you should say that. A couple of months ago I bought an original Gameboy and I'm still on the original set of Duracells I put in on day of delivery. I've played it a lot in the mean time and they show no signs of dying.

        I remember in the 90s I'd get a few hours, hot batteries and dissapointment and ended up always tethered to the wall. This direct comparison was a great example of progress to me.

        1. Anonymous Coward
          Anonymous Coward

          Re: For once the news on the battery front may actually lead to something.

          I can think of a certain Hitachi "Magic Wand" that could profit from these batteries.....

        2. FartingHippo
          Stop

          Re: For once the news on the battery front may actually lead to something.

          These are rechargeable, aren't they? So comparing to a standard Duracell seems a little misguided.

          I'd happily take a battery with 25% of the storage capacity of a Duracell if it would recharge in 5 minutes. Monster savings, both financial and environmental, to be had.

          [Also, the fact that this made it into a publication as hefty as Nature gives me a lot of hope this will actually deliver something in the future.]

  2. scrishton

    "Our battery produces half the voltage..."

    So use two in series. One 'battery' is a cell; when you connect them in series they become a battery.

    1. JetSetJim

      re: half the voltage

      I thought it was a bit weird too, and assumed they meant "by volume" - but surely they're on prototype-build rather than commercial-build, and even if the prototype is half the energy density of the Li battery, surely a commercially developed one might have a better density.

      Unless there's some physics/chemistry getting in the way of reducing component sizes...

    2. Nuusmaan

      They are mentioning "half the voltage" as an indication of a needed improvement in energy density. Explanation: Getting the same amount of energy into and out of these batteries (or cells, if you prefer) requires much more physical volume. So if you prefer a really thick smartphone, these are great.

  3. Ru'

    It's odd there's no direct mention of capacity; as above voltage is easily increased but I get the impression capacity (or power density) is pretty lame at present.

    Also is the real story that these have been designed for the new crop of bendy mobiles currently on the market?...

    1. Pawl

      Low energy density

      The aluminum cells have about a fifth of the energy density of lithium cells, depending upon the type of lithium cell you are looking at. This is actually the single-biggest area of improvement the developers are working on.

      1. Anonymous Coward
        Anonymous Coward

        Re: Low energy density

        That's why they talk about grid storage rather than a thinner iPhone. Being 1/5th as dense as LiON isn't a problem so long as they can be made 5x cheaper (including environmental impact during production and disposal)

  4. GettinSadda

    Bored of Battery "Breakthroughs"

    Every week we have at least one battery "breakthrough" that is at too early a stage to publish any results but which will totally revolutionise everything electrically powered. A year or so on if you try and track them down you find they were abandoned because of some flaw, or they are still "really close to publishing the data".

    I'm pretty much convinced that the majority of these are just ways to inflate stock prices to make a quick buck, or to win a research grant or two.

    1. Anonymous Coward
      Anonymous Coward

      Re: Bored of Battery "Breakthroughs"

      I'm bored of every breakthrough. I've read so much stuff that I've simply lost all semblance of patience. I want the cancer cure, nanobots in the bloodstream, the stacked chips, yottascale on the desktop, the super-capacitor, nuclear fusion, fusion rocket, emdrive, warp drive, AI, matter replicator, holograms, etc. and I want them now.

      1. Bronek Kozicki
        Coat

        Re: Bored of Battery "Breakthroughs"

        "... to win a grant" ... or just someone taking on popular topic for PhD work, as simple as that.

        Mine is the one without any academic papers in pockets.

      2. DropBear

        Re: Bored of Battery "Breakthroughs"

        "...and I want them now."'

        Well, I can get you holograms and supercapacitors - those actually do exist already. Will that do for the moment? Because by the looks of it we'll have to wait a few centuries at the very least for anything else on that list, if ever (and yes, that includes better batteries).

        1. Adam 1

          Re: Bored of Battery "Breakthroughs"

          No. Fusion is 10 years away.

          1. Michael Thibault

            Re: Bored of Battery "Breakthroughs"

            >Fusion is 10 years away.

            Starting when?

            1. Anonymous Coward
              Anonymous Coward

              Re: Bored of Battery "Breakthroughs"

              Starting now, for every value of now.

      3. Anonymous Coward
        Anonymous Coward

        Re: Bored of Battery "Breakthroughs"

        The best part is that I'm only half sarcastic.

  5. Mystic Megabyte
    Mushroom

    It only works with green energy?

    Someone should buy that boffin a set of red and black connectors before he has an accident.

    I too am underwhelmed with "battery breakthrough" stories.

    1. Old Handle
      Flame

      Re: It only works with green energy?

      It's okay, this doesn't catch fire, remember?

  6. Mage Silver badge

    Aluminium?

    Must use something exotic as electrolyte. The inhibiting oxide layer that forms on Aluminium is why Zinc has been used. It's hard to see how this has much different capacity to a Zinc battery of same size. The reason Zinc batteries are not rechargeable is the structure and insulating properties of the reaction products of Zinc as battery discharged. Back to thinking exotic electrolyte. So what is charging efficiency and self discharge rate?

    Also needs a lot of electricity to make Aluminium in the first place.

    I'm very sceptical as people been trying and failing to use Aluminium since late 1800s.

    Alkaline batteries can be recharged. The problem is structure, the electrode falls to bits with cycles, hence recharging of only discharged about 20% works best. Also Alkaline cells have very low self discharge.

    1. Anonymous Coward
      Anonymous Coward

      Re: Aluminium?

      Must use something exotic as electrolyte.

      Maybe it works because they pronounce it differently over there? :)

    2. cray74

      Re: Aluminium?

      "Must use something exotic as electrolyte. "

      Yep. The electrolyte was specified in the article: ionic liquid. Ionic liquids are a broad range of salts with near-room temperature melting points and finely tunable chemistry. (Honestly, ionic liquids form such a broad class that just saying "ionic liquid" is like saying "metal" or "polymer" - it tells you little by itself.) But, in general, they make excellent solvents for even materials water can't dissolve.

      For example, there's been work in electroplating aluminum in an ionic liquid bath. In water, aluminum simply reacts to form an oxide and settles to the bottom of the plating bath. In the right ionic liquid, aluminum can stay dissolved until given an electrode to plate on. I oversaw a project investigating the potential for aluminum electroplating on steel with ionic liquids. We'd knocked out the major problems like "dog bone" plating patterns and were getting good plating rates, but the process wasn't as eco-friendly as hoped. (Our ionic liquid was poisonous alone; it made chlorine and HCl fumes when exposed to moisture or too much voltage; and we needed to anodize the aluminum after depositing it). Since the money was from an environmental source in the US DoD...yeah, that stopped.

      Anyway, batteries: the same ability of the correct ionic liquid to keep aluminum dissolved without oxidizing them should work in batteries, too.

      1. cray74

        Re: Aluminium?

        Found it in the Nature: Their electrolyte is aluminum chloride and the ionic liquid 1-ethyl-3-methylimidazolium chloride. That's the same ionic liquid mixture I worked with for aluminum electroplating.

        They're right, it won't burst into flames like a lithium battery. While you wouldn't want to sprinkle it on your Wheaties, it's fairly easy to render inert - incineration does fine, as I recall - but it can cause headaches if you over-charge it or expose it to moisture.

        http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14340.html

        1. Androgynous Cupboard Silver badge

          Re: Aluminium? @cray74

          Nice work!

        2. Old Handle
          Thumb Up

          Re: Aluminium?

          Seems to have the charge value too, 70 mAh per gram, if I'm reading it right. I don't know how heavy it is so it's hard to say how that works out in volume, which might be the more important measure. But based on the AA I just weighed, and the post about energy density above, that sounds pretty good actually. An aluminum battery with the same weight as the alkaline AA I had in my office would give something like 1645 mAh.

  7. Mage Silver badge

    Capacity

    Aluminium / Carbon can't be any better capacity than Alkaline, and probably 1/2 Lithium.

    Also what is internal resistance?

    1. x 7

      Re: Capacity

      http://en.wikipedia.org/wiki/Internal_resistance

  8. x 7

    I wonder if the aluminium anode can be used as a structural component in an aircraft?

    Potential for saving overall airframe weight maybe?

    1. Anonymous Coward
      Facepalm

      > I wonder if the aluminium anode can be used as a structural component in an aircraft?

      I've no idea. But please can we have this as the structural element in a battery powered wheelbarrow before thinking about aircraft?

      1. Stevie

        But please can we have this

        as the structural element in a battery powered wheelbarrow before thinking about aircraft?

        Why? Did your Segway break down?

      2. Stuart21551

        "please can we have this as the structural element in a battery powered wheelbarrow"

        what do you need a bendy wheelbarrow for?

        1. PhillW

          going round corners?

    2. Lee D Silver badge

      I don't think you want a structural component to be at anything above ground, and you certainly don't want it to be part of a reaction.

      It will either (depending on which end of the connection it is) lose integrity, or gain potentially conductive traces, while also reacting with things around it, modifying its properties depending on its charge state, and try to discharge into any and all connected metallic structures.

      You really *DON'T* want to be using the structural parts of an aircraft for anything other than structure.

      There's a reason that you earth just about everything you can, and the first thing you do on landing is earth again.

  9. Stevie

    Bah!

    Every time I hear about this or that technology being justified against the current standard and landfill pollution I wince.

    In this case, Okay, aluminium, no problem, carbon, okay, not an issue and maybe we can sequester the carbon produced by the recharging infrastructure as cathodes for these new super-batteries.

    But was I the only one who read "polymer" as part of the build, and "liquid polymer" at that?

    Before any science twonk waves landfill stats at me I want to see the long-term environmental impact of this liquid organic material that will undoubtedly have excellent down-toward-the-groundwater seepage qualities.

    1. cray74

      Re: Bah!

      "Before any science twonk waves landfill stats at me I want to see the long-term environmental impact of this liquid organic material that will undoubtedly have excellent down-toward-the-groundwater seepage qualities"

      The ionic liquid electrolyte may be mostly neutralized with water (gets the aluminum chloride under control) and the remaining 1-ethyl-3-methylimidazolium chloride may be incinerated. I had to confirm disposal procedures for my electroplating project using the stuff because the plating baths were going to go bad over time, leaving gallons of the stuff looking for a landfill or other disposal method.

      1-ethyl-3-methylimidazolium chloride is fairly benign. It only causes moderate eye irritation and skin irritation. (Note: normal usage in industrial environments may approach 190F / 95C, at which point it's as thick and sticky as hot maple syrup. Any chemical skin irritation will be overshadowed by thermal injuries like melting your face off. See: Wafflebot's defense of Harold and Kumar.)

      It has not demonstrated any carcinogenic behavior; even California can't figure out how to label it carcinogenic. It is pretty mobile in water and not very biodegradable, but you need high concentrations in water (100mg/L) to create 50% lethality after 48 hours exposure. It is not a chronic health hazard or teratogen, either.

      Those points addressed, the "landfill stats" of 1-ethyl-3-methylimidazolium chloride is that it doesn't meet US reporting requirements under the federal Superfund or Clean Water Act, and doesn't get on California's Proposition 65 hit list, and doesn't appear on any US state's right-to-know chemical lists.

      Like I said before, don't sprinkle it on your Wheaties for breakfast. Don't stick your bare finger in the mesmerizing red, swirling plating bath because it's 190F blistering unfriendliness. But 1-ethyl-3-methylimidazolium chloride isn't mercury, lead, benzene, or methylene chloride.

  10. Conundrum1885

    Re. Bah!

    It might not be a big problem, a lot of rechargeables are now collected under WEEE legislation and lead acid recycling is quite well established.

    Also an idea I just had is to integrate the battery into the LCD panel itself thereby saving a few interconnects as the waste heat from the backlight would keep the battery warm during use which would help overcome some of the issues with running at low temperatures.

    Certainly with OLED the heat problem is fixable with a simple thermal interface similar to the one used on a plasma panel and this also allows the red OLED to directly charge the (relatively low voltage) cells sequentially rather than in series.

    1. Stevie

      Re: Re. Bah!

      Battery recycling is indeed well-established but finding out how to go about it in my locale (suburban New York) is akin to finding another Dead Sea Scroll, so the batteries all end up being dumped ... guess where?

  11. PNGuinn
    Flame

    "Our latest unpublished data suggest..."

    Yeah, right.

    According to MY unpublished data my resarch on a new ultrasafe lightweight enriched plutonium cased flexi battery with a reinforced concrete anode, tarmac cathode and super efficient snake oil electrolyte...

  12. Wzrd1 Silver badge

    Aluminum based battery that is flexible

    So, a re-invented Polaroid Polapulse battery.

    Replacing the manganese dioxide with an unnamed ionic solution.

    1. cray74

      Re: Aluminum based battery that is flexible

      "Replacing the manganese dioxide with an unnamed ionic solution."

      The ionic solution was named in other articles on the battery. I provided the link in another post in this discussion. To save you some scrolling: aluminum chloride mixed with 1-ethyl-3-methylimidazolium chloride.

  13. Anonymous Coward
    Boffin

    So just what does 'charges in minutes' mean?

    Other sites have made claims about 'charging in a minute', so let's take that seriously.

    A (current) phone battery is something like 3.8V, and something like 1500mAh. That's 5.7Wh or, in sensible units, about 20kJ of energy (the voltage and current don't matter: the energy does). If we're going to charge this in a minute, then we're going to need to dump that much energy into it in a minute: this is about 340W, and (at 3.8V) about 90A.

    All this assumes the battery is 100% efficient: I've both assumed that the voltage does not droop much as it discharges and that charging is completely efficient. Based on figures scraped from people selling phone replacement batteries, I think the voltage does not droop significantly, but I have no idea what the charging efficiency is.

    If charging is extremely efficient, then, given rather thick cables and some fairly macho connectors in the charging interface this might work. This is not going to be charging over USB: given that a dodgy connection in the charging interface would probably result in a fire I imagine these will be some kind of screw-down connectors. The currents are less than a car battery provides when starting a car (which can go up to 200A) but not much less, so the connectors are going to be the same sort of thing.

    If charging is not extremely efficient, a substantial amount of power will be dumped as heat in the device being charged. For something the size of a phone, it will need a heatsink, and possibly liquid cooling.

    Alternatively: they are making things up to get funding.

    1. Lee D Silver badge

      Re: So just what does 'charges in minutes' mean?

      "Quick charging" claims are always bogus.

      The only way to manage that is to have incredibly high voltages involved, which become a danger themselves as that allows them to arc more easily. So you'd need something like a 400V battery to make it sensible, and step-down circuitry in a mobile phone to get it back to sensible levels.

      And the batteries we use everyday, worldwide, tend to be thoroughly in the stupidly-low-voltage ranges. 12v is common, 24v is around but less common, anything higher is considered "specialist" and usually purely to avoid high currents as you specify (most larger home solar installations are 24v purely because it then halves the current so you can still use the same cables/charge controllers without having to upgrade - in some models, the charge controller and cables are identical between kits and you just change the batteries for 24v batteries as you expand the system capacity).

      Your house probably only has 100A incoming at most. You're basically saying that you're going to deliver enough current - for a short time - to power your entire house. You're talking bomb-level energies here if that goes wrong.

      There's a reason that even electric car chargers are still basically 240v (or even 400v) and HOURS of charging. I have a 32A commando connector (building site 220v connector) on the side of my house. It powers a 20A electric kiln to 1600 degrees. It's a scary amount of energy, and a scarily thick cable to do so safely, and cable thickness is related only to current, not voltage - I^2 * R. I could charge an electric car with it and it would still take hours. And, yes, that's 240v but the reason we use 240v is PURELY to decrease the current-carrying-copper-thickness required for currents (at 12v AC with the same power, we'd be pushing 20 times the current, up to 260A, just for a normal 13A appliance - and 260A requires something ludicrous like a 30mm-thick conductor for each part of the cable).

      What they are suggesting is that your mobile phone charger would somehow build up that amount of current (I assume it would build it up over time and then deliver it in one quick charge, like electric welding kit, as otherwise it would just fuse your house) down a tiny cable into a tiny battery, and get the charging time EXACTLY right and be able to detect faults quick enough to stop before the battery blows.

      It's ALL a nonsense.

      Quick charging won't happen until we have high-voltage batteries, chargers and convertors small enough to put in the devices in question. We haven't bothered to do that for electric cars yet, so fast-charging of mobile phones or AA's is still a nonsense. There's a reason your laptop batteries are 19v, because that keeps the amps down (2-3 in your average laptop?). At 12v, the same power would draw up to 5A, which needs thicker conductors throughout.

      Increased power = increased current or increased voltage.

      increased current = thicker cables

      increased voltages = more difficult voltage step-downs, less common hardware, greater arcing distance, etc.

      There's no way around it.

  14. x 7

    I'd guess the electrolyte is 1-Ethyl-3-methylimidazolium chloride-aluminum chloride - (C6H11ClN2)2 · (AlCl3)3

    Aldrich are touting it on behalf of BASF as a research material

    However use in batteries doesn't seem to be new for this kind of product, with both 1-Ethyl-3-methylimidazolium tetrachloroaluminate and 1-Butyl-3-methylimidazolium tetrachloroaluminate being reported for this back in 1994 (Carlin, R.T.; De Long, H.C.; Fuller, J.; Trulove, P.C. J. Electrochem. Soc. 1994, 141, L73–L76.)

    So perhaps this "news" isn't so new.......

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