Imagine an electric car powered by one of the most common elements on Earth – the same sodium that flavors our table salt. This isn’t science fiction or distant speculation but an emerging reality in battery science. Researchers have achieved a breakthrough in solid-state sodium batteries that could make future electric vehicles (EVs) cheaper, safer, and longer-lasting than ever.
“Recent realization of high sodium-ion conductivities (>10⁻² S cm⁻¹) in inorganic solid electrolytes at room temperature” – a development they say “will certainly trigger a boom in all-solid-state sodium batteries.”
In a landmark 2020 study published in Advanced Functional Materials, scientists reported.
In other words, the humble sodium battery is poised to upend the dominance of lithium and spark a new era of energy storage, with enormous implications for EVs, grid storage, and portable electronics.
The Lithium-Ion Dilemma and the Sodium Solution
Lithium-ion batteries have powered our world for decades – from smartphones to Tesla cars – but they come with significant drawbacks. Lithium is relatively scarce (sodium is ~400 times more abundant in the Earth’s crust), and lithium-based batteries often require costly, hard-to-source materials like cobalt and nickel.
This drives up prices and links batteries to problematic supply chains. Safety is another concern: the liquid electrolytes in lithium-ion cells are flammable, contributing to the rare but alarming fires in EV crashes and battery plant accidents. Finally, lithium-ion performance can falter in extreme temperatures; cold winter mornings or scorching summers can reduce an EV’s range and reliability.
Sodium-ion batteries offer a compelling solution to these issues. Sodium is cheap and plentiful, obtainable from sea salt or common minerals, which means sodium batteries could slash costs and ease resource bottlenecks. Analysts estimate that sodium-ion cells might cost around $50 per kWh to manufacture, versus about $70 per kWh for today’s lithium-ion cells.
In practical terms, this ~30% cost reduction could make electric cars more affordable and grid storage projects more economically viable. Moreover, sodium-ion chemistry inherently avoids lithium’s most problematic quirks: sodium batteries are “much safer, less reactive than lithium and able to operate more efficiently over a wider temperature range,” offering good performance even in sub-freezing cold
The idea of a battery that doesn’t easily catch fire and shrugs off the cold has automakers and engineers paying close attention.
Cracking the Code of Solid-State Sodium Batteries
If sodium is so great, why haven’t we been using it all along? The challenge is that sodium ions are larger and heavier than lithium ions, which historically made it difficult to achieve high performance. They tend to move sluggishly through materials and can wreak havoc on battery components not designed for them. This is where the 2020 breakthrough comes in.
Scientists have been developing inorganic solid electrolytes (solid materials that conduct sodium ions) to replace the traditional liquid electrolytes. By fine-tuning these crystalline materials at the atomic level, they’ve created superhighways for sodium ions to zoom through. The result: several experimental solid electrolytes now conduct sodium ions as fast as (or even faster than) the liquids in lithium batteries.
One striking example from the research is a class of materials called sulfide electrolytes. By tweaking the chemical recipe (for instance, substituting a small fraction of phosphorus with tungsten in a sodium sulfide framework), researchers introduced tiny vacancies – empty sites that sodium ions can hop into. Think of it like creating “fast lanes” in the crystal for ions to travel.
The payoff was huge: a tungsten-doped sodium sulfide achieved an ionic conductivity of about 13 mS·cm⁻¹ at room temperature, (1 mS·cm⁻¹ is 0.001 S·cm⁻¹), which is “far higher than that of liquid electrolytes” used in standard batteries.
In fact, some of the newest sodium solid electrolytes boast conductivity above 40 mS·cm⁻¹ (0.04 S·cm⁻¹) at room temp, surpassing even the best liquid electrolytes on the market.
For comparison, this level of performance rivals the ionic speed in conventional lithium batteries – a stunning feat that just a few years ago scientists weren’t sure was possible.
How did they crack the code? The Advanced Functional Materials report explains that it comes down to mastering the fundamentals of ion transport.
By studying crystal structures, lattice vibrations, and defects, researchers identified the key levers that govern how easily sodium ions diffuse. Crystal structure is crucial: certain frameworks have channels or tunnels perfectly sized for Na⁺ ions.
For example, a ceramic known as NASICON (sodium zirconium phosphate) provides a stable skeleton where sodium can zip through, albeit moderately. Defects and doping are another lever: adding trace dopants or creating sodium vacancies can dramatically boost ionic mobility by giving ions more room to hop.
And lattice dynamics – essentially the way atoms wiggle in the solid – can assist conduction if the material is engineered to have flexible, vibrating cages that ease the passage of ions.
The outcome of all these tweaks is a new generation of all-solid-state sodium batteries (ASS-SBs) that deliver impressive lab results. High ionic conductivity means such a battery can charge and discharge quickly (good for rapid charging and high power output) and can function well in the cold (since the ion pathways remain active even at low temperature).
In short, scientists have shown that sodium-ion batteries can overcome the traditional performance gap and compete head-to-head with lithium on a technical level – a dramatic paradigm shift in energy storage research.
Solid-State Advantages: Safety, Stability, and Longevity
Beyond performance, switching to a solid electrolyte unlocks major safety and longevity benefits. In a conventional battery, ions move through a flammable liquid organic solvent. In an all-solid battery, that flammable liquid is gone – replaced by a non-combustible ceramic or glassy material. This means no risk of leaking or fire under normal operation. As the researchers note, these inorganic electrolytes have “good thermal stability with much higher onset temperatures” than liquids
Some can tolerate heat well above 100 °C (212 °F) without breaking down, and one prototype solid sodium battery even continued to operate stably at 350 °C (662 °F) in testing
(For reference, a typical lithium battery would fail long before such extreme heat – or worse, go into thermal runaway.) For EV owners, this could translate to batteries that are far less likely to overheat during fast charging or heavy use on hot days.
Another game-changing advantage is the potential to use metallic sodium as the anode (the battery’s negative electrode). Today’s lithium-ion batteries can’t safely use pure lithium metal anodes in most products because the liquid electrolyte would react and form dangerous dendrites – needle-like metal deposits that grow and short-circuit the cell.
But with the right solid electrolyte, sodium metal becomes viable. Certain solid electrolytes are chemically stable against sodium metal and are even “envisioned for the use of metallic sodium anode,” being impervious to Na dendrites
In practice, this means we could do away with the heavy graphite anodes used in lithium-ion cells and replace them with lightweight sodium metal foil. That boosts the energy density (more energy stored for a given weight) and improves battery life, since a stable solid electrolyte can prevent dendrite formation and the catastrophic failures they cause. In fact, the study highlights that while many super-fast sodium conductors have narrow electrochemical stability, a few special compounds (like sodium β″-alumina, Na₂B₁₂H₁₂ borohydride, and Na₃OBr) are remarkably stable against sodium metal
Pairing these with a Na metal anode yields a battery that’s both high-capacity and safe from internal shorting.
Long lifespan is another promise of solid-state sodium batteries. Without volatile liquids and with carefully engineered interfaces, these batteries can minimize the degradations that plague conventional cells (like electrolyte breakdown or thick SEI layer growth).
Early test cells have shown encouraging stability. For example, a prototype solid-state sodium battery using a NASICON-type electrolyte and a Na₃V₂(PO₄)₃ cathode retained about 91% of its capacity after 100 charge-discharge cycles.
Another design using a doped sulfide electrolyte held around 90% capacity after 100 cycles as well, even when cycling at moderately high rates.
These are short-term tests, but the negligible capacity loss hints that with further optimizations, sodium batteries could achieve the multi-thousand cycle lifespans needed for EVs and grid storage. Indeed, researchers found they could get nearly 99.7% coulombic efficiency per cycle in some cells (meaning almost no loss of charge with each cycle).
With solid electrolytes preventing side reactions and self-discharge, a well-built sodium battery might reliably last for a decade or more of daily use – true long-lasting power that drivers and device owners will appreciate.
Driving EVs Forward with “Salt Power”
The most exciting application for this technology is undoubtedly electric vehicles. A sodium-based solid-state battery pack checks almost every box for an ideal EV power source: it’s cheaper, safer, performs well in heat and cold, and could potentially offer high energy density. For consumers, this could manifest as EVs with lower sticker prices, longer driving ranges, and peace of mind about battery fires or degradation.
Cost and materials are a huge driver here. By cutting out expensive lithium and cobalt, sodium batteries free automakers from volatile commodity markets. Sodium, iron, carbon – these are inexpensive, widely available materials. Manufacturers like CATL (Contemporary Amperex Technology Co., the world’s largest battery maker) are already investing heavily in sodium-ion tech. In 2023, CATL announced that the Chinese automaker Chery would be the first to use its sodium-ion batteries in a production EV.
CATL’s first-generation sodium car battery packs deliver around 160 Wh/kg of energy density (comparable to some lower-end lithium-iron-phosphate batteries), and the company projects the next generation topping 200 Wh/kg, closing the gap with mainstream lithium packs.
Importantly, CATL reports these sodium cells can charge to 80% in just 15 minutes and still retain 90% of their capacity in -20 °C conditions.
Such specs make them well-suited for real-world driving: quick pit-stop charging and reliable winter performance, all with a battery that’s inherently non-combustible. As one industry blog put it, sodium-ion batteries are shaping up to be “worth their salt” in the EV world.
From a driving perspective, an EV with a solid-state sodium battery could offer a very secure experience. You might never have to worry about a battery fire even in a severe collision. Parking in a hot garage or running the vehicle hard on a track day would carry less risk of thermal runaway.
In cold climates, owners would see less range drop-off on frigid mornings (since the sodium cell chemistry doesn’t freeze up as much as lithium). And because these batteries aim for longer cycle life, the dreaded battery replacement many years down the line could become a rarer occurrence – the battery might outlast the car itself.
Major automakers outside of China are also exploring sodium-ion tech for future EV models. In 2024, global players like Stellantis (Fiat-Chrysler/Peugeot) and startup battery makers such as Northvolt signaled plans to develop sodium-ion batteries for certain vehicles
The initial target market seems to be affordable, city-oriented EVs where range requirements are lower and cost is critical. Think of compact cars that could sell for much less than today’s EVs by using sodium batteries, or hybrid battery packs that combine lithium and sodium cells to balance performance and cost.
While lithium-ion will likely remain dominant for high-end, long-range cars in the immediate future, sodium-ion is charging up from the sidelines. Even capturing a small slice of the massive EV market (analysts project ~3–5% of new EVs could use sodium batteries by 2030) would be a game changer, spurring further investment and improvements in the technology. And as solid-state designs mature, we could see sodium-based EV batteries competing even in premium models for ultimate safety and longevity.
Grid Storage and Gadgets: The Broad Impact
The revolution in sodium batteries isn’t limited to cars. Grid energy storage – the giant battery banks that back up renewable energy farms and stabilize the electricity grid – stands to benefit enormously from sodium technology. In grid applications, cost, safety, and lifespan trump weight or size considerations. Utilities want batteries that are cheap per kWh, safe to install in large numbers near cities, and can last for many thousands of charge cycles. Sodium-ion fits that bill perfectly.
With sodium’s raw material advantage and the ultra-stable solid-state design, future grid batteries could be deployed at lower cost and with virtually no fire risk (an important factor when battery farms are located near communities). In fact, high-temperature sodium–sulfur batteries have been used for grid storage for decades – operating at ~300 °C with molten sodium inside.
These proved that sodium-based systems can be reliable workhorses. Now, room-temperature solid-state sodium batteries promise to do the same job with less maintenance and complexity. According to CATL, their sodium-ion cells are flexibly adaptable to energy storage needs, and perform impressively even in extreme climates.
We can imagine container-sized sodium battery banks soaking up solar power all day, then delivering it at night without breaking a sweat – and without the costly cooling and fire-suppression systems that lithium megapacks require.
Portable electronics might also eventually join the sodium party. Today’s smartphones and laptops are unlikely to switch from lithium-ion in the very near term (because every gram counts for handheld devices, and lithium cells still have an edge in energy density).
But the gap is closing. If researchers hit the ~200 Wh/kg mark and continue to improve cycle life, sodium-ion batteries could start appearing in devices where safety is paramount or where cost needs to be ultra-low. Consider gadgets for children, e-bikes and scooters, or home backup batteries – having a battery that won’t flame out if damaged is a big plus in these cases.
Moreover, by alleviating the demand for lithium in EVs and grid storage, sodium batteries indirectly help our gadgets too: the price of lithium for consumer electronics could stabilize or drop once EVs (which use the bulk of lithium supply) diversify their chemistries. It’s a win-win scenario – lithium and sodium each finding their ideal niches.
A “Salt-Powered” Future
The story of sodium batteries is quickly evolving from an esoteric science project to a tangible technology that could touch all of our lives. It’s a prime example of how innovative research (in this case, on solid electrolytes and fundamental ion transport) can translate into practical, world-changing applications.
For the public, the impact could be profound: electric cars that are more affordable and safer, a more resilient electric grid that can handle the ups and downs of renewable energy, and gadgets that last longer and pose less risk. Each of these improvements inches us closer to broader adoption of clean energy and electrified transportation – key steps toward global sustainability and climate goals.
Perhaps most remarkably, this revolution is powered by an element that is literally everywhere. Sodium doesn’t require conflict minerals or environmental devastation to obtain; it can be sourced in countries all over the world, from salt flats to seawater.
That means a future where energy storage is not constrained by geopolitics or scarcity, but is as accessible as the salt in your kitchen. One can’t help but feel a sense of awe and optimism at the elegance of it: solving high-tech energy problems with one of the oldest, most familiar substances known to human civilization.
In Jonah Berger’s terms, this breakthrough has all the ingredients of a viral idea. It gives people Social Currency (“Have you heard about the new EV batteries made from salt? They’re game-changing!”), it’s naturally Triggering (every time you see a salt shaker or an EV, you might think of it), it carries Emotional weight (hope for safer cars and a greener planet), it’s becoming Public (with demonstration cars and battery packs hitting the market soon), offers clear Practical Value (cheaper, safer energy affects us all), and it’s backed by a compelling Story – the quest to reinvent the battery using a common element, decades after lithium sparked the portable electronics revolution.
The sodium battery era is just beginning, but its potential is immense. Scientists and engineers often remind us that there’s no single solution to the world’s energy challenges. Yet, as we develop this new technology, it adds a powerful tool to our toolbox. The next time you drive an electric car or store renewable power, the energy keeping you going may very well be delivered by sodium – a simple element, turned into a powerful story of innovation. The road to a cleaner, electrified future may, in fact, be paved with salt.
