The battery of the future might just be table salt — and that's the whole point

Climate & Energy 4 min 79 sources

Sodium-ion batteries — made from salt instead of scarce lithium — are cheap enough and good enough to reach the market, while a $400M storm bill and a Walmart nuclear deal show the grid's slower moving parts still grinding on.

Key takeaways

Sodium-ion "salt batteries" — made from cheap, abundant salt instead of scarce lithium — are now good enough to reach EVs and the grid, and could pull battery prices down while loosening China's grip on the supply chain.
Massachusetts utilities filed contracts for three big grid batteries (over 4,400 megawatt-hours) that store cheap daytime power and release it at the evening peak — the job gas plants used to do.
The grid's slower machinery keeps grinding: a Texas utility owes $400M for gas bought during the 2021 Uri freeze, and Walmart signed its first nuclear deal as demand for firm clean power spreads past big tech.

The most interesting battery in the world right now is made from something you can buy for a dollar a kilo.

Salt is coming for lithium

For fifteen years, the rechargeable battery has meant one thing: lithium. It powers your phone, your car, and increasingly the electricity grid. But lithium is a scarce mineral, expensive to dig up and refine, and China controls most of the supply chain [9]. This week, a detailed New Scientist survey laid out how fast its cheaper rival is arriving [9].

The rival is the sodium-ion battery — a “salt battery.” It works the same way a lithium battery does, but it swaps lithium for sodium, which comes from ordinary salt: abundant, cheap, everywhere [9]. In February, the Chinese carmaker Changan ran the first mass-produced sodium-ion EV down an icy track at −32°C to prove it holds up in the cold [9]. Its battery, built by the storage giant CATL, is expected to reach the market later this year [9].

The catch has always been weight. Sodium is three times heavier than lithium, so a salt battery storing the same energy is bulkier [9]. For years that pinned it to two uses where bulk doesn’t matter: grid storage sitting still in a field, and small, short-range cars [9]. But the specs have improved. One study found a sodium-ion battery from the maker Hina now rivals Tesla’s lithium cells on most measures, though still about a third heavier [9]. CATL claims its version reaches 175 watt-hours per kilogram — enough to compete with the cheaper lithium batteries in low-cost Teslas [9].

Salt has other quiet advantages. It doesn’t slow down as much in the cold — CATL says its cells keep 90% of capacity at −40°C — and it runs cooler, so it’s less likely to catch fire and needs less spent on cooling systems [9]. General Motors, the biggest US carmaker, just partnered with the start-up Peak Energy to build sodium-ion storage; the same batteries are going into data centres and, in the UK, home batteries [9].

Why this matters for you. The reason your EV, phone, or home battery costs what it does is partly that lithium is scarce and largely controlled by one country. A second, cheaper chemistry made from a material nobody can corner is the kind of thing that pulls prices down and takes a supply chain out of any single government’s hands. It won’t replace lithium — it’ll sit beside it, each chemistry suited to a different job [9].

The grid buys the storage it needs

The salt-battery story is really a storage story, and storage is where the money is moving. Three Massachusetts utilities — Eversource, National Grid and Unitil — just filed contracts for three big battery projects totalling 1,068 megawatts and 4,472 megawatt-hours of capacity, due online by 2030 [15]. One of them, Jupiter Power’s Trimount project, is a single 2,800-megawatt-hour battery sitting on a former fossil-fuel plant site [15].

What does a grid battery actually do? It stores cheap power when supply is high — a sunny or windy afternoon — and releases it when demand peaks, usually the early evening [15]. That’s “peaking capacity,” and it’s the job gas plants used to do. These batteries also ease “transmission congestion” — the traffic jam that happens when more electricity wants to flow through a wire than the wire can carry — around Greater Boston [15]. Massachusetts is chasing 5 gigawatts of storage by 2030, with plans for another 5 by 2035 [15].

The bills from old storms and new demand

Two reminders this week that the grid’s slower gears are still turning.

In Texas, a judge ordered the utility CPS Energy to pay nearly $400 million to the pipeline company Energy Transfer for natural gas bought during Winter Storm Uri — the deadly 2021 freeze that took down the Texas grid [45]. CPS had sued back, arguing Energy Transfer used the disaster as cover to “price gouge,” charging “unconscionable” amounts as gas prices spiked [45]. The judge ruled against that argument entirely [45]. Five years on, the storm is still generating invoices.

And a sign of where the pressure is heading: Walmart signed its first-ever nuclear power deal, a long-term agreement with Constellation Energy for up to 176 megawatts of nuclear electricity to run its Illinois operations from 2029 [12]. Big companies buying nuclear power directly has mostly been a tech-company move so far, driven by the enormous electricity appetite of artificial intelligence [12]. A retailer joining in is a small signal that the scramble for firm, always-on clean power is spreading past Silicon Valley [12].

02 · Lesson · why it matters

Why the best material loses to the one that's everywhere

The thing that wins at scale is rarely the thing that performs best — it's the good-enough thing you can make from what nobody can run out of.

The salt battery isn’t better. It’s everywhere.

Lithium makes a better battery than sodium. It’s lighter, it packs more energy into less space, and for phones and long-range cars that matters a lot. On pure performance, lithium wins.

And yet the salt battery is arriving anyway. Not because it beat lithium — it didn’t. Because it doesn’t need lithium. Sodium comes from ordinary salt, which is cheap and sits in every ocean on Earth. Lithium is scarce, expensive to refine, and its supply chain runs mostly through one country.

So the contest was never really “which battery is better.” It was “which battery can we make a billion of, cheaply, without asking anyone’s permission.” On that question, the worse material wins.

The bottleneck isn’t performance — it’s the input

Here’s the thing that’s easy to miss when you compare two technologies side by side. You look at the specs. Energy density, weight, charging speed. Lithium’s numbers are better, so lithium should win.

But a technology doesn’t scale on its specs. It scales on its slowest, scarcest input. Lithium’s best number doesn’t help if the mineral is dug up in a handful of places, refined by a handful of companies, and priced by whoever controls the supply. Every phone and car you want to build has to squeeze through that narrow opening.

Sodium has worse specs and no opening. There’s no queue for salt. And a good-enough thing with no queue will out-produce a perfect thing stuck in one. This is why the salt battery is going to data centres and home walls and cheap cars — the places where “cheap and available forever” beats “light and dense.”

We’ve watched this happen before, without noticing

The pattern isn’t about batteries. It’s about what decides which version of a thing takes over.

The container ship didn’t win because it was a beautiful piece of engineering — it won because a standard steel box is dumb, cheap, and stackable anywhere. Concrete beat finer building materials for most of the world because sand and gravel are everywhere. The crops that feed the planet aren’t the most nutritious ones; they’re the ones that grow almost anywhere and store without spoiling. Again and again, the version that spreads is not the finest one. It’s the one whose ingredients don’t run out and don’t belong to anyone.

The “best” version keeps its crown in the narrow places where performance is worth any price — luxury, aerospace, the frontier. Everywhere else, abundance quietly wins.

Scarcity is also power, and abundance dissolves it

There’s a second half to this, and it’s the part that’s easy to miss.

When a thing depends on a scarce input, whoever controls that input holds a lever over everyone downstream. Control the lithium refining and you have a say over every carmaker who needs it. Scarcity isn’t just a cost — it’s a chokehold, and it’s often somebody’s chokehold on purpose.

A good-enough substitute made from something abundant doesn’t just lower the price. It takes the lever away. Nobody can corner the market on salt or sand or sunlight. When the input is everywhere, no single hand can squeeze it. That’s why the arrival of the salt battery is really two stories: a cheaper product, and a supply chain that slips out of any one country’s grip.

What this asks of us

So the next time two things are compared and the better one is losing, it’s worth asking a quieter question than “which is best.” Ask: what does each one need to exist, and who controls it?

We are all downstream of this. The price of the car, the phone, the electricity, the food — a piece of it is decided not by which technology is finest, but by whether its key ingredient is abundant or scarce, free or owned. Most of us never see that layer. We see the finished thing and assume the best design won. Usually, what won was the thing you couldn’t run out of — and no single seat, ours included, can see the whole tangle of inputs and levers that decided it.

03 · Lab · your turn

The Scale-Up Choice

Rehearse choosing between a best-in-class scarce material and a good-enough abundant one, and feel how scarcity becomes a chokehold as demand grows.

04 · Hope · carry this

The tools that change the most lives are rarely the fanciest ones — they're the ones cheap and plentiful enough for everybody to have. A battery made from salt is a reminder that progress often arrives not as a breakthrough for the few, but as a good-enough thing for the many.