Rock Salt May Lead The Way To Better Batteries

The regular refrain here when it comes to announcements of new battery chemistries hailed as potentially miraculous is that if we had a pound, dollar, or Euro for each one we’ve heard, by now we’d be millionaires. But still they keep coming, and it’s inevitable that there will one or two that break through the practicality barrier and really do deliver on their promise. Which brings us tot he story which has come our way today, the suggestion that something as simple as rock salt could triple the energy density of a lithium-ion vehicle battery.

The research led from Lawrence Berkeley National Laboratory started around the use of cobalt in the battery cathode, an expensive and finite resource with the added concern of being in large part a conflict mineral from the Democratic Republic of Congo. Cobalt is used in  the cathodes because its oxide crystals form a stable layered structure into which the lithium ions can percolate. Alternative layered-structure metal oxides perform less well in retaining the lithium ions, making them unsuccessful substitutes. It seems that the three-dimensional structure of a rock salt crystal performs up to three times better than any layered oxide, which is where the excitement comes from.

Of course, if it were that simple we’d all be using three-times-more-powerful, half-price 18650s right now, which of course we aren’t. The challenge comes in making a rock salt cathode which both holds the lithium ions, and keeps that property reliably over the thousands of charge cycles needed for a real-world application. This one may yet be anther dollar on that metaphorical pile, but it just might give us the batteries we’ve been looking for.

Then again, when you’re looking at exciting battery chemistry, why limit yourself to lithium?

58 thoughts on “Rock Salt May Lead The Way To Better Batteries

  1. “… something as simple as rock salt …”
    They aren’t talking about halite aka NaCl. It’s DRX, disordered rock salt oxides, something like Li1.2 Ni1/3 Ti1/3 Mo2/15 O2.

  2. I have a better solution: stop forcing EVs down our throats.
    They will improve over time so more people will switch over.
    And the grid will slowly able to handle more.
    If you ban IC cars before we’ve developed a scalable technology you are creating a recipe for disaster.
    We didn’t ban horses when Ford created the model T either.

    1. hmmm… a quick google came up with “Most experts believe the horse and buggy days started to fade out around 1910 when the horse and buggy was replaced by the automobile. Once the railway and personal automobile became readily available to the middle class, the horse and buggy fell out of favor as a mode of transport.”
      The model-t was released in 1908. I get your point, but you might consider another example to bring your point across.

          1. Probably because horses naturally come with “full self driving”.
            There are stories of milkmen in the UK, whose horse often knew the route better than they did.

          2. Horses are easy to fright and running away, and they sometimes get aggressive towards people and trample them, so I guess they are similar to modern “self-driving” cars.

      1. The Model T was long after automobiles were invented. It was a representation of economies of scale finally making cars more practical. Even then, it still took two more years for the claim you are citing.

      2. The analogy is fine. Horses actually increase in popularity initially and cars only surpassed horses around 1925 (source:
        Horses were never banned and are still allowed. People switched over because the automobile was superior in almost every way. It’s a good thing it wasn’t replaced overnight as infrastructure and traffic rules needed time to adapt to the change.
        EVs have to potential to be superior in almost every way to IC cars, but they currently are not.
        They need to become cheaper, longer range, safer, lighter, and easier to charge (enough grid capacity and charging stations). In my opinion hybrid cars are a good alternative, but they are lumped together with regular IC cars in many policies.

        1. Your perception that EVs are being shoved down your throat is a little off. You’ll be able to buy brand new IC vechicles for at least another 12 years and then only CA (and a few states directly following their lead) has put forth a ban, IIRC. Practically, that means US sales of IC vehicles will almost certainly be absent before that, but that leaves a whole decade to build up this infrastructure you’re fear-mongering about. You’ll still be able to buy used ones and run them on the road after that. Most modern hybrid vehicles aren’t good enough and they have high complexity problems. The drive train of the Chevy Volt is absurd and I have a friend with one that couldn’t be fixed by the designers when the transmission started acting up (they just replaced it). Once most of them move to PHEV where the ICE is only used as part of a genset I might agree with you that hybrids are the way forward, but those are basically non-existent right now.

          1. There are tightening standards and limitations for ICEs like fuel consumption and CO2 emissions per km that are cramping the performance of the cars down to the point of practically banning them, because the legislators are trying to proverbially squeeze blood out of a rock. Already the upcoming economy regulations in the EU mean that a common car should travel down the highway with about as much power as a lawnmower, while EVs suffer no such penalty. That’s what the “shoving down our throats” is about – they’re artificially making ICE cars useless.

          2. And regarding the fuel economy rules; it applies to the fleet average, so if a car manufacturer wants to keep selling normal cars with normal performance, they HAVE to sell EVs to offset the fact that the ICE cars just can’t physically meet the regulations. Otherwise they face penalties in the billions of dollars/euros, which means somehow the manufacturers have to shovel EVs down people’s throats to stay in business. A regular fuel burning car becomes a luxury affordable to the few.

          3. “The drive train of the Chevy Volt is absurd and I have a friend with one that couldn’t be fixed by the designers when the transmission started acting up (they just replaced it).”

            Note, that for a while (before the Volt) several car manufactures have a sealed “no-maintenance” transmission policy (Looking at you BMW). Where their transmissions are not designed to be repaired or maintained (you can’t even have the fluid changed). If they fail and take it to the dealer you will be buying a replacement.

            (Side note, you can find independent garges that will attempt to service them, change fluids, etc. and extend their service life.)

          4. EVs get high subsidies paid by taxpayers. At least in the Netherlands (not everyone on hackaday is from the US). That is forcing it on people.

            “I might agree with you that hybrids are the way forward, but those are basically non-existent right now”
            That’s because the EVs are pushed in favor of hybrid. It’s a circular reasoning to use that as an argument for EVs.

          5. irox:
            There are car manufacturers that say: ‘sealed trans’ (notably ZFs customers).
            There are _no_ transmission manufacturers that say that (notably ZF).

            It’s mostly the Germans making their terrible cars even worse. There is a simple solution to that.

            Even my German cousins aren’t denying it anymore.
            10 years ago, no VWs ever again. (Audis and Porsches are just VWs.)
            Now, no Benzes ever again.
            Soon. no BMWs ever again.

          6. @HaHa

            Yeah, ZF even recommend fluid changes on the “sealed” transmission at 60K miles. Although one of the problems is you can only drain around half the fluid each change. So maybe the transmission is good until 120K miles (and past the warranty date/miles), but when you can only change half of it at a time you need to start early to void too much old fluid.

          7. Much better to judge by what’s actually consumed or emitted, as long as you treat the EV fairly by accounting for where its power comes from even though it will still win. If someone manages to find a way to make a non-EV that’s more efficient than batteries and the grid, then the same criteria would recognize that and rank it as better. However, the amount of co2 emitted per km from the energy a normal EV uses is going to be very hard to raise above the amount emitted even by a lawnmower going down the road.

            Who cares if the EV has more horsepower? It’s like how in this century, I can afford to light my home brightly because I mostly use electric lighting. It’d be strange if I had to use very little light even though I have LEDs just because somebody else who has a grease lamp will be offended that my house is brighter than theirs.

            What’s good about a fleet average is that if someone truly can’t use an EV, they still have a regular car available. If every car had to meet the same standards, then some of them would be impossible to make and others would have no incentive to be improved. As it is, if the economy cars get more efficient, then the trucks can still be sold to those who need them.

      3. And EVs were the most popular automobiles until automatic starters were invented, once that happened the obvious advantages of ICE cars drove EVs out of the market, and ICE is still the best technology we have today.

        1. You’re going to need to define “best” because that’s a very overbroad statement. The best for you and your personal desires for what a vehicle should be? Maybe. There are many metrics by which a vehicle can be evaluated. No vehicle drive train type wins on all metrics.

          1. OK, let me be more specific, the matter is energy storage, the simple fact is that a tank of gasoline has higher energy density, can be “charged” much faster and hold it’s “charge” much longer than a battery of equal size and greater weight. Unless there is a quantum leap in battery technology ICE vehicles are the “best” vehicle technology we have today.

          2. To add, gasoline also provides heat, so your car can stand outside and still operate while and EV needs a heated garage or spend much of its charge on warming the battery up. Gasoline also doesn’t “self discharge”, and the engine doesn’t have a “vampire load” that slowly drains the fuel as you let it sit, and the fuel tank isn’t destroyed if you leave it empty for too long.

          3. @Dude Have you never had anything with a gas engine that sat for too long? Because I have had fuel leak/evaporate, I’ve had it go bad in the tank and the lines of things that hadn’t been used for awhile, and I’ve even had it clog carbs when I didn’t get them bone dry before parking the engine – even though I ran it dry on purpose. The solution of course being to burn the fuel before it goes bad and add more after – which isn’t really better than self-discharge. Of course, an engine with a 12v starting system will do both, so you have to keep it charged anyway.
            Plus… a gas engine consumes plenty of fuel idling. So the consumption of not doing anything is not a great advantage here for engines in either interpretation.

    2. Well.. if you want government to keep out of it we could just end all oil subsidies. Maybe stop giving oil companies spots in our national forests which are supposed to be for conserving nature too. Let them buy their own land and pump their own oil on their own dime.

      Of course that would be far too extreme which is why it’s not happening. The economy couldn’t adapt fast enough. So stop crying like a little baby that it is happening! It’s not. Even in those very few places where new gas car sales are banned or scheduled to be banned used ones will be on the road for a very long time.

      Also, if gas beat out electric back in the 1900s based on it’s practicality alone, not based on the government “shoving gas cars down our throats” WTF are oil subsidies for?

      Give me a free market when it benefits me, command economy when it doesn’t and grab the pitchforks when anything looks like change?

        1. Greenies are dishonest.

          I’ve heard the claim that gas taxes are gas subsidies from them. Delivered with apparent straight faces.

          They also claim airports are money losers…Are cash cows. They do this by ignoring all revenue from parking and on terminal vendor leases.

          There are many more.
          Like bible thumpers, they believe they are lying for a good cause. Hence it’s all good.

    3. The amount of extra energy needed from the grid is somewhat similar to the amount of power that we saved by switching to LEDs for lighting in the U.S. However the lighting was a more continuous load. I can agree that charging networks are a legitimate problem, since they’re often either broken or someone’s parked in them without actually using the charger. I’d charge at home, if I had an EV, but I got a cheap used work truck instead since the things that get better mpg (currently 26) would not be practical for me or would cost too much more. However they would be practical for a whole lot of people other than me, people who are the ideal market for such vehicles but refuse to even look at them. People aren’t going to buy electric without prodding until it’s twice as good as anything else and strokes their ego besides.

      Of course I think some people’s vehicles should still have engines for longer than others, but the only people who think ICE vehicles won’t be allowed on the road in a few years are the extremes on both sides. One side is the ones who think everyone’s able to go out and buy an expensive tesla tomorrow no matter what they currently drive. The other is the ones who get deeply offended if you say it’s rude and immature to roll coal or that if they’re not going to tow or go in deep mud, they are just wastefully LARPing in their $75k truck. I think hybrids should be a bigger part of the plans, but even if we transition straight to electric very abruptly, it’s still going to be decades before you can’t pick up a decent, reliable used ICE vehicle if that’s best.

      Anyway, better batteries are the major way to make them improve over time, which is what you say you want. If this or something like it ends up being something that makes EV’s better and makes the batteries even less harmful to produce, we should all be happy about it.

      1. You are parroting a talking point from an EV advocacy . If you look at public records and perform the calculations yourself, you will realize that energy savings from LEDs will not provide the tiniest fraction of power needed to support a country-wide auto fleet, and in no way does it address the grid’s complete lack of surge ability.

          1. I encourage you to show your calculations and cite / link to the government statistics they are based on. I have also looked at the numbers and assess that you are off by at least an order of magnitude.

            US EIA estimates that total U.S. energy consumption for lighting in 2022 was 213 x 10^9 kWh

            Applying a conversion factor of 3412 BTU per kWh gives total lighting demand of 7.27 x 10^14 BTU equivalent.

            Estimates of power requirements to transition to EV vary. This article
            which is based on an IEEE report estimates that the transition to EV will require an additional 6.3 quads or 6.3 x10^15 BTU.

            Even if LEDs reduced lighting energy demand to zero that would only provide 11.5% of EV the requirement. In practice the LED energy savings will be a lot lower since to a large extent they will be replacing fluorescent/CFL lighting at this point, not incandescents.

          2. Reply to Joe Shaw: the change to LED lighting has already mostly happened, and [spaceminions] was comparing the energy/year already saved to ultimate electric vehicle energy/year requirements. If we assume that LED lighting is about 5 times as efficient as the mix of fluorescent/incandescent that existed in, say, 2000 CE, then I’d estimate that an all-electric vehicle fleet in the U.S. would take about 2X the electric energy saved by the change to LED lighting. Not 10X, and not the same.

          3. Joe, the common knowledge figure of relevance is that supposedly people drive about 37 miles a day, 1.1k per month, 13.5k per year. With 300Wh/mile as a ballpark for an EV, then they would consume 12kWh/day, 330/month, 4000/year. I’m using very rough figures everywhere, because I just want to see if it’s similar – half or twice as much would be dead-on accurate by that criteria.

            The driving is a per-capita average figure so the other one also needs to be looked at in a similar frame of mind. The other figure is what you might find more debatable, since it’s a little harder to account for lighting that *would have* been used if we hadn’t gone down a different path of history. Your link was for residential and commercial although that’s not all the total categories, so I’ll use that and ignore industrial lighting and such for now.


            About 20 years ago, we used quite a bit more than the recent 213 TWh/yr for those categories of lighting despite a lower population of 282 million. Most of the worst efficiency was incandescent in residences, but replacing fluorescent tubes in businesses also made a significant dent in consumption. I don’t have my original source for this, which didn’t exclude other categories in our modern consumption. The old figures linked above which I found with a little searching just now seem in line with what I remember at around 600 Twh. If we had consumed at the same per capita rate the whole time while increasing population to 332 million, we’d be consuming about 706 TWH/year for those two categories. Since we’re at 213 instead, I’d say we saved at least the difference. If we pretend that the unaccounted for percentage is 25% on both years, and changed at the same rate, then I can just divide by 75% to get the estimated savings of 657 TWh/year.

            Since wasted heat from indoor lighting represents an additional load on any air conditioner that’s running, that sometimes adds a penalty. They’re used most days in the south but less often in the north, and usage has shifted over time, plus they’ve gotten a lot more efficient over time. So this one is hard to estimate but it’s not the worst to estimate that it takes an additional one-third of the consumption of the lights to make up for their output heat when there’s an air conditioner running in that place (and none when there isn’t – if it’s cold the heat is welcome). You can also get into radiant heat and the effect on thermostat settings, but that’s a bit too complicated. Let’s just say the range is now somewhere between 1 and 1.33 times the savings we find from lighting alone.

            Per capita, that comes to at least 2000 kWh/year, but if you’re somewhere warm it might be more like 2600. Still short of 4000, but still not that different really. If a few more things were accounted for, or if we picked a more efficient estimate for an electric car, it could draw closer. To put it another way, more than half the cars could be replaced with EVs before we’d make up the difference, and the median car is over 12 years old, so by the time we get to that point we’ll probably have improved efficiencies even more.

            Sure, at the end of the day we did end up going for more efficiency instead of more capacity, so if we don’t hurry up we’ll have issues. But it’s not an incomprehensible amount of power, really.

    4. Very flawed argument. 1. No one banned IC vehicles when EVs were created either. Like Horses, however, the banning will come in time. Yes, Some states did in fact ban horses on highways. Delaware has the fastest approaching ban, set for 2025, but that is still, 13 years after the release of the Model 3. Most other states with planned bans aren’t until 2035. Louisianna made it illegal to ride horses on roads in 1950, some 48 years later. Most other states just prohibited it. So either your beef is about timeline, or banning your preferred method of locomotion, but it can’t be about both in the context you provided. 2. The model T’s rapid adoption was not preceded by the infrastructure. Roads were still meant for horse and buggies, and places with refueling centers were the places that saw the first and primary market growth. You are arguing that in 12 years, places like California are going to suddenly need to provide electrical capacity to replace the
      14 million vehicles it currently has rather than accept the reality that it will be closer to about 30 years before California see a majority stake of EVs on it’s roads.

      Also, what does “down our throats” even mean? Not a single state has banned the use of IC vehicles now or in the future. 1. Hydrogen Cell vehicles are IC vehicles and no one is proposing a ban on those. 2. The bans are for the sales of CO2 emitting vehicles. Your comment reminds me of all those people in the early aughts pissed that ethanol blends would be allowed because they were cock sure that they would not be able to get gasoline that wouldn’t torpedo their engines. Here we are, some 23 years later and a. Those people have always been able to fuel their vehicles and 2. 95% own a vehicle now in which that argument is irrelevant and c. no, they weren’t forced to do anything they weren’t already going to do, which is buy a new vehicle. And the ones still driving a vehicle manufactured pre-2001 are still able to purchase non-ethanol fuel in places. Hells, unleaded gas was on the market for 26 years before the US banned leaded gas sales, and people were complaining even then about it.

      1. “No one banned IC vehicles when EVs were created either”
        They are being banned right now! Diesel cars are banned in more and more cities. Production of new ICE cars are banned in the near future. Taxes on gasoline are increased and emission standards become stricter to make ICE cars unaffordable, while EVs receive high subsidies.
        Horses are still allowed on non-highway roads in many countries.
        “The model T’s rapid adoption was not preceded by the infrastructure. Roads were still meant for horse and buggies, and places with refueling centers were the places that saw the first and primary market growth”
        That’s exactly my point! The infrastructure is not ready for mass adoption of EVs. Yet they are being pushed.
        “You are arguing that in 12 years, places like California are going to suddenly need to provide electrical capacity to replace the 14 million vehicles”
        No I’m arguing the exact opposite! This won’t happen no matter how much people want it! That’s why forcing it on people is bad policy.
        “Also, what does “down our throats” even mean? Not a single state has banned the use of IC vehicles now or in the future”
        State? I’m not specifically talking about the US. Not everyone on hackaday lives in the US. Welcome to the internet! Forcing trough subsidizing and banning.
        “The bans are for the sales of CO2 emitting vehicles”
        They include plugin hybid cars too. Those can run without emitting CO2 for most trips.

        1. Clearly there’s some confusion about what you’re dealing with where you live since everyone assumed you were from the USA. Could you provide a bit more information about the kind of bans you’re seeing implemented?

          You seem to be under the impression that modification of pricing of these vehicle types is the end goal of these changes in laws. Emission standards are being tightened to reduce pollution. The side effect is that it costs more to develop and produce more efficient ICE-based drive trains. Subsidies are being provided for EV purchases because they are known to be less polluting than ICE vehicles. Subsidies adjust the relative ratio of purchases made such that there is less pollution being produced.

          Do you feel like you’re being persecuted due to your strong preference for ICE vehicles?

          1. “Could you provide a bit more information about the kind of bans you’re seeing implemented?”
            I already listed examples. Bans of diesel cars in major cities (such as Amsterdam). Banning of production of new EVs in the near future. Higher taxes on fuel(10$/Gallon gas) and higher tax on ICE cars.

            “Emission standards are being tightened to reduce pollution.”
            Reducing pollution is good. But regulations can be too strict or becoming strict too fast. EVs also pollute. And in many ways pollute even more. And making new cars more expensive will make people drive in their older, more polluting cars, longer.

            “Do you feel like you’re being persecuted due to your strong preference for ICE vehicles?”
            The people that are in charge hate freedom and hate people who love freedom. They are ideologically driven and not democratic. They are destroying the middle class.

    5. The fact remains that the development of a “perfect” storage battery today will not address the real barrier to the electric fleet pipe dream– that conversion of the US auto fleet to electric would not only require a power grid at least 10x the size of the present, it would also require the unprecedented need to service obscene surge demands… something the grid was never designed for.

      I accept that small fleets of routine-limited-travel vehicles may successfully transition to all-electric…postal trucks or inner-city taxis for example. But for day-to-day use by average citizens–particularly in large states with large open areas– EV mandates are nothing but grift…a way to make a handful of rich people richer while the middle class’ freedom becomes progressively more erroded.

      Any “solution” that requires forced mandates and/or bribes to implement is highly suspect.

      1. And we realistically have 20+ years before it has to handle the full brunt of <25% (I'd guess closer to 10%) of the full US fleet of vehicles charging simultaneously. We have time to build the infrastructure because the bans are on new sales only. ICE vehicles aren't being banned from the road and you'll be able to buy and run used ones to your heart's content after the bans go into effect.

        1. It’s becoming increasingly difficult to buy gasoline and it’s only going to get worse. 15 years ago there were 4 gas stations within 5 miles of my house, now there are only 2. As petroleum-powered vehicles become a smaller fraction of the national fleet, owning a gas station is going to become economically infeasible and more stations will close. It will be the inconvenience of obtaining gasoline, not the unavailability of petroleum-powered vehicles, that will signal the practical end.

          1. I’m not sure where you live, but I’ve only witnessed an increase in the number of gas stations near me. If you’re in the US, I’d wager the disappearance of those stations are a sign of the state of your local economy and not due to EVs.

      2. Since you say the 10x isn’t from peak demand, it must be the overall energy usage you’re thinking of. In my rural household, which is the least suited for electric vehicles, to use 10x as much energy as we do now we’d still probably need to find an EV that’s over 10 times as wasteful as the hummer EV everyone makes fun of. Current electric commuter cars are more than twice as efficient as the hummer, and by the time any of us needs another vehicle, there should be further improvements.
        So the amount it would increase our power consumption is between one-third and one-half, but as long as it’s not charging at the same time as everyone’s cooking dinner, it’s not too much for the grid even for us. I believe we consumed almost as much back before we got various efficiency-improving stuff. For us with our amount of driving, you’d have to add in some other things we’ve done in the last 10-15 years to improve efficiency. For instance, the newer air conditioner, shade and reflective films on some of the windows, reduction in power draw from things that run 24/7 like a decades-old freezer or lots of old electronics… But you could probably add up to about the same in the end.
        This isn’t a crazy amount of power, all things considered. It does mean that there could be more incentive to keep baseload fossil plants operating at night, but they are better than any current non-hybrid cars I know of as far as efficiency and emissions.

    6. Sure. Let’s just keep using the cheaper and more convenient thing that is actively killing us until the underdog tech somehow outcompetes it.

      You can’t have 5 billion ICEs.
      You can either have less good EVs, or take the bus/train.

      Your refusal to support good public transit in favor or your own personal convenience is what is “forcing” EVs on you, not anything else.

        1. Yes, but heard of the tragedy of the commons? Sometimes, individuals maximizing their individual goods may lead to the individual goods actually going down. Consider this: some action of an individual gives him a lot of good, but a lot of individuals is harmed a little. This is no problem, until a lot of individuals start doing the same thing: now the little harms sum up, and start to affect you (and everyone else) significantly.

          1. Tragedy of the commons situations happens when there’s no communication between the parties involved, or the “parties” act in a pure game-theoretical way which ignores information about the other players. The common example is the prisoner’s dilemma, where actually, when both parties know that the situation is the prisoner’s dilemma they will co-operate rather than sabotage each other.

            Usually people point to the tragedy of the commons in order to justify why they should be given the power to control a bunch of other people, but that is always assuming the people are ignorant and stupid. These attempts at power then produce the opposite effect, where people reject the point because they see it being used as an excuse for a political power grab, and THAT then leads to the tragedy of the commons anyways.

      1. “Sure. Let’s just keep using the cheaper and more convenient thing that is actively killing us until the underdog tech somehow outcompetes it”
        It’s not killing us. EVs have higher emissions than a modern diesel by the way.
        “You can’t have 5 billion ICEs”
        You can’t have 5 billion EVs either. What’s your point?

        “You can either have less good EVs, or take the bus/train.”
        There are plenty of other options. You can take an ICE car. You can walk. You can use your bike. Who are you to restrict modes of transportation?

        “Your refusal to support good public transit in favor or your own personal convenience is what is “forcing” EVs on you, not anything else.”
        I’m not refusing to use public transit. I use it quite a lot. I’m for freedom of choice for transportation. I’m against banning/restricting ICE cars and against pushing/subsidizing EVs.

          1. You can come to any conclusion you like if you massage the raw data long enough until it suits your needs. Same as cotton vs. polyester fabrics or organic vs. conventional food.

  3. There’s a 1911 electric vehicle down the street at the petersen automotive museum along with a 1912 & I believe a 1915. Being a nickle based Edison battery, you didn’t recharge, just added new electrolyte

  4. Stories about amazing battery breakthroughs are fine. The problem is the general population doesn’t realize that it takes a dozen breakthroughs to even start using a battery chemistry and a dozen more before it’s practical.

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