Aluminium-Sulphur Batteries For Local Grid Storage?

Lithium-Sulphur batteries have been on the cusp of commercial availability for a little while now, but nothing much has hit the shelves as of yet. There are still issues with lifetime due to cell degradation, and news about developments seems to be drying up a little. Not to worry, because MIT have come along with a new battery technology using some of the most available and cheap materials found on this planet of ours. The Aluminium-Sulphur battery developed has very promising characteristics for use with static and automotive applications, specifically its scalability and its incredible charge/discharge performance.

The cell is based upon electrodes constructed from aluminium metal and sulphur, with a electrolyte of molten catenated chloro-aluminate salts. With an operating temperature of around 100 degrees Celsius, you’re not going to want this in a mobile phone anytime soon, but that’s not the goal. The goal is the smoothing out of renewable energy sources, and localised electricity grid balancing. A major use case would be the mass charging of battery electric vehicles. As the number of charge points increases at any given location, so does the peak current needed from the grid. Aluminium-Sulphur batteries are touted to offer the solution to ease this, with their high peak discharge current capability enabling a much higher peak power delivery at the point of use.

Right now many of us have household solar installations utilising LiFePo battery technology, with the sheer cost of the battery units limiting the amount of capacity that is installed. Aluminium-Sulphur batteries could easily replace them at a fraction of the cost. With a cost-per-cell less than one-sixth that of Lithium Ion, and construction from extremely common materials, this might be just the technology to disconnect us from the global lithium and cobalt supply chains and enable many more people to generate and make use of electricity in our own homes, after all, the sun doesn’t shine all day.

Lithium-Sulphur technology still shows some promise, here’s a little thing about that. If you were wondering what the deal is with lithium, and why it could be a problem in the future, then do checkout this piece from a couple of years back. Food for thought, certainly.

via [MIT News]

45 thoughts on “Aluminium-Sulphur Batteries For Local Grid Storage?

  1. Many will mention all of the “revolutionary battery technology” of the last 10 years that never made it to market. In general, it really doesn’t matter if the technology is commercially viable, practical, or even works at all. It only matters that these startups can attract venture capital so they can buy their sports cars before the pipe dream evaporates. (Of course, I know “this time is different”.)

      1. That guy had a vision. Shows a picture of an aluminium smelter and quotes how many millions of amps it draws, and says “we need to teach that thing to be a battery”. Grid scale storage works when you can make each cell very large, as it reduces the interconnects and complexity. Also helps retain heat if the things need to sit around at hundreds of degrees. Having literal tons of molten metal laying around is probably fine.

        Antimony – salt – magnesium or something. Operates with anode, cathode and electrolyte all in liquid state. Densities of the fluids keeps them separate

    1. Unnecessarily negative. You techno-cynics are the no.. 1 holdup in the world of creative advances by new tech start-ups. By inflating the risks artificialy with your cynicism, You scare off otherwise valuable investment by belittling founders stating- ” it only matters …that startups can buy their sports cars”
      This is merely Your cynical opinion of a small no. of a few bad apples.

  2. The problem of course is cost. It’s much cheaper to use grid-scale storage and power generation than it is to have it on site. That said, I’m not reading about an obscene amount of battery storage being deployed which makes me think the economics of it are still iffy.

    1. I’m not sure the cost really works ‘much cheaper’ grid-scale – the individual/company/estate can know their supply and demand well enough to provide only as much as they need, and if its important to them shift the loads around a little to keep matching the supply/demand.

      The grid on the other hand is black magic to the users as long as it works – they don’t know or care as long as everything turns on when they want it to, and they can’t adjust at all for the supply/demand situation as they don’t know it! So grid scale quite likely ends up used less efficiently and requires greater oversupply.

      Then you have to account for grid scale needing new land purchases, quite large blocks of it, probably a few years of fighting with the NIMBY crowd to get permission to build it, with its shear output potential a good amount of supporting infrastructure upgrades are to be expected, along with lots of regulatory red tape – not unjustified as a really big energy store is rather more dangerous than the baby sized ones. Where a ‘small’ battery of some sort can just disappear into most existing buildings isn’t powerful enough to need major infrastructure changes or any greater danger in being there than the gas line etc.

      Both methods clearly have pro’s and con’s, but economically especially with current energy price trends I’d say both are very likely solid investments.

      1. The thing about “knowing about supply and demand” is that when they have a grid storage they don’t need to spin up more base power systems for a known short term spike, and the same is also true when demand suddenly drops – instead of burning excess off (w/ resistive loads) they can divert it to grid storage instead. All the lessons learned from large scale grid storage consisting of batteries point to it saving a lot of money for several reasons, the systems to date typically pay for themselves within 3-5 years.

        And in regards of land purchase, red tape etc, getting permits for a grid scale storage is a damn sight easier than getting one for building a new powerplant or expanding a current one. And purchasing land, a grid scale storage can be placed almost anywhere as long as it is near power distribution infrastructure.

        A big energy store isn’t particularly more dangerous than a battery situated in a building, I would argue the latter is more dangerous since buildings tend to contain people whereas a grid storage is an unsightly thing that’s located far outside population centers with very few people around.

        1. Indeed, my point was its all down to how you try to calculate it economically – as per kwh if grid store isn’t massively cheaper you are doing something wrong, but by % of required energy needs met it may well be much more expensive – as the load currently has no understanding of the current state or investment in keeping it running where it should – that is somebody else’s problem, so invisible. Which means you could end up needing much more capacity, which then makes it more expensive by that measure. But as I said both styles are especially at this moment looking like very good investments!

          The land thing really depends on where you are – there isn’t much land in the UK for instance that isn’t already farmland we shouldn’t loose more of, protected from development for ecological reasons or covered in existing buildings mostly already in use for something – land here is expensive and hard to get compared to most places.

          A big energy store has many potential dangers made greater by its shear scale if something goes wrong – it is just much harder to control the problem and/or fix it – where your tiny battery even if it goes spectacularly wrong doesn’t have the energy to be nearly as dangerous. Though you are correct more people are likely to be in vicinity – but where there are lots of people you also get faster emergency response and usually more failsafe and protective systems as we put high value on ourselves. Plus with a bigger disaster possible with a bigger energy store the radius you don’t want to be inside is very much larger too – so again depending on just how far away you can locate such things…

          1. Oh and of course that the purely per kwh installed isn’t the only part of the equation as to cost effectiveness – you can put a small battery in a building for its own needs and require basically nothing but the inverter and battery. You can’t put a huge energy store anywhere without expanding the infrastructure to deal with it – a cost not directly tied to the ‘battery’ but required to make it work properly.

        2. “A big energy store isn’t particularly more dangerous than a battery situated in a building, I would argue the latter is more dangerous since buildings tend to contain people whereas a grid storage is an unsightly thing that’s located far outside population centers with very few people around.”

          Or make it look like a building.

      2. Having this on the distribution side can have negative impacts upon gtid operations as well. It would be an unknown quantity to the grid that could add up to be a problem.

        Case in point is solar in California. The grid operators were seeing cut outs from solar stations when transients hit the grid. These solar sites would trip off the controllers. For say 800 MW solar generation lost on the grid, they would actually lose about 1,200 MW due to 400 MW tripping off on the distribution side.

        That can be dificult to deal with and adhear to NERC rules.

      1. Prove it or STFU with your tin foil hat.

        Reality is it’s very hard to get something like this out of the lab & into mass production and the media love to over-hype any potential breakthroughs / progress without stopping to understand how far away from commercialisation they are.

        1. Joking aside, the reason (partly) why we dont invest more into coal to hydrocarbon conversion is that the long term price of oil is lower than the typical cost of the equivalent synthetic alternative.
          Since these things are done commercially – ie profit above all other reasons, not clever things like energy independence and strategic planning; is why no one invests in the tech.
          Not because it wont work, but because capitalism is riddled with short term views and “when am I going to get paid”.

    1. Exactly, if you believe the headlines, we’ll very soon have almost limited capacity for pennies. In fact we should have already, since these kinds of headline have been a thing for at least a decade.

  3. “What’s more, the battery requires no external heat source to maintain its operating temperature. The heat is naturally produced electrochemically by the charging and discharging of the battery.”

    This suggests that round trip efficiency is not that great. No mention of round trip efficiency in the article.

    This technology seems best suited for stationary applications, and Not Suitable for automotive.

    LiFePO4 cells are still expensive per energy stored, but are Very Efficient, ~97-99% round trip.
    However, LFP cells cannot tolerate temperature extremes, and are best operated at 5-35 Celsius.

    So many tradeoffs to ponder!

  4. What would be the issue with lead-acid batteries for stationary storage applications? I realize their weight & power density limitations for EV’s but that is not an issue for a basement.

    1. They’ve worked great for decades in telecom applications.

      Most of the problem is management and business level issues.

      For example, pull something like Powersonic’s lead acid technical manual vs a similar lithium battery datasheet or manual and compare the technologies.

      The battery efficiency is “about” the same around 95% roundtrip, etc.

      Where problems develop is lead acid batteries need to be babied and temperature compensated and smart charged if you want maximal performance, but there are HUGE financial incentives to not doing that because you get to sell more replacement batteries, etc. If you abuse a lead battery the company making it and the system integrator and the service guys all get more money. So sure just dump in a high constant current, who cares how hot it gets as long the electrolyte isn’t boiling, etc. That makes piles of money for everyone except the owner, LOL, and the owner doesn’t get a vote in the design process LOL. If you buy a large enough lead bank to not abuse the battery WRT charge and discharge rates, then you have a VERY long lived and reliable battery system but it’ll be incredibly large and expensive such that you’re better off abusing and rapidly replacing a smaller cheaper lithium system.

      If you abuse a lithium cell, it just explodes and nobody makes money after the lawsuits.

      So lithium based systems will always perform better at storage than lead systems because financial and legal reasons, not technical EE reasons.

      1. “They’ve worked great for decades in telecom applications.”
        That’s only for backup power where they’re usually being topped off to full capacity.

        Forklifts are one of the examples of lead-acids being routinely deep cycled hard, but for that to be viable:
        Weekly “equalization” overcharges
        Topping off water in the battery once every few months (to compensate for water lost in “equalization”)
        Still a typical service life of only a few years

    1. Why does the temperature raise warning flags for you? 100°C is the temperature of boiling water, something that billions of people generate and store safely every day. Well, maybe just around one billion now that I think of it, but the technology to safely contain a 100°C liquid is _very_ mature by this point.

      1. Yep, I was going to say the same thing. 100 degrees C is not exactly extreme, especially in an industrial setting. If it was 1,000 degrees it might raise an eyebrow.

        1. well 100C water and 100C oil (or syrup) is different because different thermal properties and stickyness. so is 100C salt which is possibly caustic or toxic. it probably can be contained, but don’t think it’s as safe as spiling hot tea on the table… so precautions should be taken.

      2. “Why does the temperature raise warning flags for you?”

        Because water is generally boiled for short periods each day.
        Until the Commenter above mentioned that it only needs to reach 100°C during charging/ discharging, I was concerned about the additional heat that would be present and the need for additional cooling to the building (local storage) over most places on this planet (in which is a concern of people who say the sky is falling/failing).

    1. I think even in the UK, “sulfur” is now the accepted spelling, at least in scientific/engineering publication. Non-technical outlets still use the “ph” version.

      (Even the BBC quiz show “Pointless” uses “sulfur”, and they have explained why.)

  5. I’d still like to see NiFe batterys make a bit of a comeback. I would like to know if they could be partnered with solar panels in a rural environment to practically power a home.

    The cons:

    • They aren’t as energy dense as modern batteries. But that’s why I specified rural environments, where one could spare room for a medium sized shed to fill with them.

    • They have a high self-discharge rate making them not practical for long term energy storage but the sun always comes up tomorrow, it’s only a day away. So they only have to make it through the night. And if occasionally dark clouds mean they have to last longer then well.. I guess one can occasionally use grid power. Does everything have to be all or nothing to be worthwhile?

    • They can emit hydrogen, but with a well programmed charging controller that can be minimized. Ventilation can be provided just to be safe.

    • And they do occasionally need topped up with water. But with a good charge controller that shouldn’t be necessary very often. And it’s not like people in rural areas aren’t typically used to watering things.

    ** So why with those disadvantages would I be interested in such a thing **

    • Cheap. They can be made inexpensively. Nickel, Iron and Potassium Hydroxide. Certainly easier to obtain than Lithium!

    • Less harmful to the environment. I wouldn’t drink it but certainly better than other batteries if it spills!

    • Long life. These things are known to last 40 or 50 years needing only occasionally to be watered. After that just swap out the electrolyte and start the counter back at day 1. That fact alone makes them a winner for the environment because you only have to build it once!

    • Durable – over-charge it.. you lose water and release hydrogen. Re-water it and it’s good to go. If it freezes.. well, so long as the case was made to not break open from the water’s expansion as it freezes the battery will be as though nothing happened once it thaws.

    • They don’t catch fire. Well, so long as you ventilate any hydrogen.

    • Did I mention cheap and long life? I’m not aware of anything that can even come close to a NiFe battery on those two points.

    1. I feel like I was reading right here on HaD that the apparent downside of NiFe, the venting of hydrogen when overcharged, could actually be a bonus, especially in big, fixed, grid-storage applications. Your suburban NiFe grid-stabilising battery could be generating hydrogen in time of oversupply of renewables. That hydrogen could then be stored or sold, e.g straight into the local natural gas network.

  6. Ws planning on doing my AZ property with NiFe batteries; post Covid lockdowns there are almost none to be found. The only semi-reliable company in the US to provide them stopped supporting and went to LifePO4. Really kicked my wife and I as we had a plan built around these. Could try to get them from China, but saw poor ratings for nearly all suppliers there. Used to be called Edison batteries, some of which are still functional today (80-90 years after manufacture.) Sad really… run water through ash and replace your electrolyte!

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