An electric vehicle's success depends on its battery. But what makes a battery "good"? It's a balancing act. In this lesson, we'll explore two new battery technologies that could power our future. We'll compare their strengths and weaknesses to recommend the best fit for different needs.
Hook: The Impossible Triangle
Work with a partner. Imagine you are buying a new electric car. You can only have TWO of the following three benefits. Which two do you choose? Why?
- Long Range: Drive the farthest distance on a single charge.
- Low Price: The car is more affordable.
- Fast Charging: The battery recharges in the shortest amount of time.
Discuss your choice and be ready to share your reasons with the class. This is a common problem for engineers called a trade-off—improving one area often means sacrificing another.
Reading: The Next Generation of Batteries
For decades, lithium-ion batteries have powered everything from phones to cars. But they have limitations. They can be expensive, and the materials can be difficult to source. Two new types of battery chemistry are emerging as strong competitors: Sodium-ion and Solid-state.
Read the information about each technology. Pay attention to the key differences.
Sodium-Ion (Na-ion)
Sodium-ion batteries work very similarly to lithium-ion batteries, but they use sodium, which is one of the most abundant and cheapest elements on Earth. The Chinese company CATL has already started mass production, with its batteries now powering the world's first mass-produced sodium-ion EV.
- Cost: Significantly cheaper than lithium-ion. Sodium is easy to find and process.
- Safety: Generally considered safer than lithium-ion. They are less likely to overheat.
- Cold Performance: This is their most impressive feature. They perform much better in cold weather, losing very little of their charge.
- Energy Density: This is their main weakness. They are less dense than lithium-ion batteries, meaning they store less energy for their size and weight. This results in a shorter range for vehicles.
- Charging: They can be charged very quickly.
Solid-State
Solid-state batteries are a major change. Instead of a liquid electrolyte (the material ions move through), they use a solid one. This changes everything. Toyota aims to commercialize these batteries around 2027-2028 and has partnered with major suppliers to prepare for mass production. Other major automakers, like Nissan, are also racing to bring solid-state technology to market by a similar date.
- Cost: Currently much more expensive to produce than other batteries. The manufacturing process is complex.
- Safety: Potentially the safest of all battery types. The solid electrolyte is not flammable.
- Cold Performance: Performance in the cold is still a challenge for engineers to solve.
- Energy Density: This is their greatest strength. They are the densest batteries, meaning they can store much more energy in the same space. This could lead to EVs with a range of over 1,000 km.
- Charging: They promise incredibly fast charging times, potentially 10-80% in just 10 minutes.
Watch: A Challenger to Lithium
Watch this video from CNBC to learn more about how sodium-ion batteries are positioned to compete with lithium-ion technology.
How Sodium-Ion Batteries May Challenge Lithium
CNBC explores the re-emerging technology of sodium-ion batteries and their potential to challenge the dominance of lithium-ion batteries.
Video Transcript
The future is electric. Everything from cars to consumer electronics to renewable energy storage is dependent on our ability to build more and better batteries. Today, lithium-ion batteries dominate those markets, but demand for the critical minerals needed to make lithium-ion batteries is predicted to outstrip supply. That, combined with cost considerations and concerns over energy security, are leading companies and countries to consider alternative battery chemistries. "With challenges around, say, lithium, nickel, cobalt supply, you some OEMs have turned to sodium-ion." [ 00:33 ]
Sodium-ion batteries have a similar design to lithium-ion batteries, which means the two can be manufactured using similar methods. Both generate electricity through a chemical reaction and are made up of an anode, cathode, separator, and an electrolyte. But in a sodium-ion battery, lithium ions are replaced with sodium ions in the battery's cathode, and lithium salts are swapped for sodium salts in the electrolyte. Like lithium, sodium, which is part of salt, needs to be chemically processed before it can become the feedstock that goes into the cathode and electrolyte. Sodium is right by lithium on the periodic table, which means that the two are chemically very similar, but sodium is much more abundant. It's also cheaper. [ 01:13 ]
Although still in its infancy, the market for sodium-ion batteries is expected to be worth over $11 billion by 2033. While sodium-ion batteries can't compete with lithium-ion batteries in terms of range in electric vehicles, they do present some unique advantages. "It doesn't use the expensive raw materials. There's no cobalt, there's no copper, there's no lithium, there's no graphite, which is really primarily controlled by China today. What we're actually going to see is a production Natron battery cell that's been fully charged, and actually, we're going to drill straight through it with a hole saw. And what we're going to find is it's just going to sit there. There's no safety hazard, there's no fire." [ 01:51 ]
Chinese battery giant CATL recently announced that it would supply automaker Chery with sodium-ion batteries for its EVs. Other battery companies like SVOLT and French-based startup Tiamat are pursuing similar technology. CNBC spoke to two companies, California-based Natron Energy and UK-based Faradion, about their plans to commercialize sodium-ion batteries and the technology's place in the evolving battery market. [ 02:25 ]
Sodium-ion batteries have been around since about the 1970s and '80s, but large-scale development of the technology was abandoned in favor of lithium-ion batteries. But now the technology is getting a second look. Excitement around sodium-ion batteries was reignited after the world's largest EV battery maker, CATL, revealed it was investing in the technology in 2021, with plans to establish a basic industrial supply chain by 2023. Similar to lithium-ion batteries, sodium-ion battery cathodes can be made of different materials, which companies are experimenting with to give their batteries specific properties. But overall, the materials used to make sodium-ion batteries tend to be cheaper than the materials used in lithium-ion batteries. [ 03:07 ]
"This cell, about 80% of the cost of the cell is the materials. And if you compare it with the bill of materials for lithium in volume, you're looking at between 24% to 32% less expensive for the bill of materials for sodium-ion compared to lithium-ion." Besides doing away with lithium, sodium-ion batteries do not require the use of other critical materials like cobalt, which has been associated with human rights abuses. Plus, sodium can be found anywhere. "It is hugely abundant. You know, it's not just widely available in terms of the current sources of sodium in seawater, but is contained in the crust of the Earth around the world as well." [ 03:46 ]
"Lithium, a majority of that is within, you know, basically three countries: Australia, China, and Chile, and developing to be, you know, a handful of more countries, but still hugely concentrated. 70% or so of the current cobalt production is in the Democratic Republic of Congo. And again, the vast majority of that is being refined in China. So, these are obviously key bottlenecks in terms of the supply chain." [ 04:10 ]
Another draw of sodium-ion batteries is that they have a longer cycle life, meaning that the battery can be charged and discharged more times than lithium-ion batteries and can operate in a wider range of temperatures. "With sodium-ion batteries, we have a very wide temperature operating range, so down to -30 and all the way up to +60. Also, we've demonstrated capability to go up to +80°C as well. And that again is because of the intrinsic elements of the electrolyte and the materials that we're able to use." [ 04:42 ]
Battery fires have also been an issue that's dogged lithium-ion technology, but experts say sodium-ion batteries will be much safer. "With lithium-ion, you always need to have 30% to 40% charge in a battery. That's why when you get on a plane and they ask you to take out your batteries if you're going to check in a bag, it's for those reasons because they can become unstable and catch fire. And sodium-ion is very unique in that way that we can ship these at zero volts. So it's like essentially shipping a bag of electrolyte, not an active battery." [ 05:14 ]
For all of its advantages, the Achilles' heel of sodium-ion technology has been its energy density, which is the amount of electrical power a battery can store with respect to its mass. What this means is that in order to hold the same electrical charge, sodium batteries need to be bigger and heavier than their lithium counterparts, which can be a problem for EVs where space is limited. Today, sodium-ion batteries have an energy density similar to that of lithium-iron-phosphate batteries. Lithium-ion chemistries containing nickel, manganese, and cobalt have the highest energy densities. These energy densities translate to range in electric vehicles. Despite its diminished range, experts say sodium-ion technology has a promising future, and companies are rushing to ramp up production. [ 05:57 ]
One of those companies is Faradion, which was founded in the UK in 2011. In 2022, Indian conglomerate Reliance Industries acquired the startup for $135 million. "Reliance-owned captive demand is massive. They have the largest oil refinery in the world moving to renewable energy. They have one of the largest telecom companies in the world with Jio, and they have one of the largest retail businesses in the world. So there's all these power requirements, there's delivery vehicles, there's telecom applications." [ 06:30 ]
The cathode in Faradion's battery cells is a chemistry known as sodium layered oxide and contains sodium, nickel, manganese, magnesium, titanium, and oxygen. The anode is made of hard carbon, which comes from coconut shells or other biomass materials. Quinn says Faradion is initially focusing on producing batteries for the stationary energy storage market. This can include things like providing backup power for telecom companies or storing excess energy generated by renewable resources like wind and solar, either on the grid scale or in individual homes. Next, Faradion plans to expand into the low-speed electric vehicle market. Think electric bikes, scooters, and rickshaws. Heavy machinery like forklifts are also a contender for Faradion batteries. [ 07:11 ]
Faradion installed its first sodium-ion battery for energy storage in Australia in 2022. The company says its batteries are already competitive with lithium-iron-phosphate technology. "In our production-size cells, they're currently at 160 watt-hours per kilo, and we've got development activities that are taking us to 190, 200-plus watt-hours per kilo." As it continues to improve the energy density of its batteries, Faradion does see a future where it moves into the EV market, starting with commercial vehicles such as buses and trucks that have more room to accommodate larger batteries. [ 07:46 ]
"EV is a more crowded space, it's a much more challenging market, it requires a lot more capital, and there's longer design cycles. On the other hand, you know, because there's so much interest in our technology, it's certainly important to be on their roadmap and to be collaborating with some of those companies because you do want to be able to have a seat at the table." [ 08:09 ]
The challenge for Faradion now is scaling up production. The company is building an R&D facility in the UK to continue developing its technology as well as working on expanding production with factories in India. "We're building up pilot facilities to go into the, you know, hundreds-of-ton range, both from the material side and cell manufacturing side, and then also in parallel building up the gigafactories to be able to go up into the gigawatt-hour scale per year." [ 08:36 ]
Natron Energy is another company trying to commercialize sodium-ion battery technology. Founded in 2012 in Santa Clara, California, as a spin-off of Stanford University, Natron focuses on making sodium-ion batteries using a sodium-rich material based on the pigment Prussian blue. "Prussian blue is a consumer product. It's a pigment you'll find it in paint, blue jeans, all sorts of things. It turns out that it's also great at storing energy in the form of sodium ions. In general, it is a relatively simple compound to formulate. Any chemical plant with, you know, quality control and process control to make, you know, high-purity material can make Prussian blue." [ 09:13 ]
For its battery cells, Natron uses a sodium material rich in iron for the cathode and a manganese-rich sodium material for the anode. "The anode and the cathode electrodes are deposited onto aluminum foil, similar to what you'd have in your kitchen. The packaging is made of this laminate material that's aluminum foil coated with plastic. In between the two electrodes, we would have some kind of separator, and that separator is effectively plastic wrap with a little bit of silica, so glass dust embedded into the plastic. And that's really about it." [ 09:44 ]
Natron has outsourced production of its electrode material to specialty chemical maker Arxada in Switzerland. The company is continuing its R&D efforts and runs a pilot-scale production line where it says it can produce between 100 and 200 battery systems per month. One of the advantages of sodium-ion technology is that it can use the same manufacturing plants as lithium-ion batteries. Natron is taking advantage of this, partnering with Clarios to use part of the lithium-ion battery maker's Michigan plant to begin large-scale manufacturing of its sodium-ion batteries in the fall of 2023. [ 10:14 ]
"The beauty of that specific plant is it's sort of medium volume. You know, it gives us an opportunity to prove that we can manufacture these sodium-ion batteries on lithium-ion lines before we then go out and build a global-scale plant. But at some point in 2024, next year, we're going to be running this plant at a rate of about 3.5 to 4 million battery cells per year." [ 10:38 ]
The company is not initially focusing on the EV market. Instead, Natron is targeting the data center market, where it says its batteries can provide backup power in the case of an outage. EV fast-charging stations are another possible future market. Natron is already testing this application with investor Chevron. "You imagine pulling into the station, there are a whole bunch of chargers there, and all the cars plug in at the same time. And now the power load on the electric grid is enormous. It can be really hard for the grid to support all those vehicle chargers simultaneously. And so a lot of station operators are actually moving to a model where they would put big stationary batteries in the station to provide those pulses of power to charge the vehicles." [ 11:19 ]
United Airlines has also invested in Natron and plans to use the company's batteries to electrify its ground operations. Wessells says that Natron has raised about $175 million since its inception from a number of investors, including ABB and CSAA Ventures, among others. [ 11:39 ]
Natron and Faradion are just two of a number of companies trying to commercialize sodium-ion battery technology. This as a number of carmakers have already announced plans to incorporate sodium-ion batteries into their electric vehicles. As with lithium-ion technology, China is leading the charge in embracing sodium-ion batteries. Out of the 20 sodium battery factories now planned or already in construction around the world, 16 are in China. "The domination that China has in the current lithium supply chain, there is a risk that that now extends to the sodium-ion supply chain, depending on where sodium cell production capacity is built out. And at the moment, it's looking like China is going to dominate in that too." [ 12:20 ]
Most experts believe that sodium-ion batteries have the potential to act in tandem with lithium-ion technology, alleviating some of its supply constraints rather than replacing it entirely. "Ten years out, I think sodium-ion is going to have a very strong position in industrial power and grid energy storage. For electric vehicles, there are going to be certain market segments where sodium-ion is a great fit. The jury is really out on whether or not that's going to include mainstream passenger vehicles." "We can see a future in which there could be a lower-cost sodium-ion option, and that could be a lower trim line on a car, and it may not have quite the same range, but it would be less expensive." "I think where you're seeing lithium-iron-phosphate, you'll see sodium-ion taking market share. I mean, lithium-ion has a couple of decades' head start over sodium-ion, so we will certainly be taking market share on that for some foreseeable future." [ 13:14 ]
As with any new technology, success usually comes with scale, which sodium-ion battery companies have yet to build out. "Keeping up with the scale of growth of the battery market is going to be one of probably the largest challenges for sodium-ion to reach large market penetration." Still, sodium-ion battery manufacturers remain optimistic about the technology's future. "This is a once-in-a-generation transition from fossil fuels to green energy on a global basis, and sodium-ion is going to continue to play a big role with that." [ 13:44 ]
Language Focus: Comparisons & Purpose
When we compare technologies, we use comparatives and superlatives. When we explain why a choice is made, we use clauses of purpose.
Comparatives & Superlatives
We use comparatives (e.g., cheaper, safer, more expensive) to compare two things. We use superlatives (e.g., cheapest, safest, most impressive) to compare three or more things, or to highlight a key feature.
Sodium-ion batteries are cheaper than solid-state batteries.
Solid-state batteries have a denser energy profile.
The most impressive feature of Na-ion is its cold performance.
Safety is perhaps the most important factor for public transport.
Purpose: in order to / so that
We use in order to and so that to explain the purpose or reason for an action. in order to is followed by a base verb. so that is followed by a clause (subject + verb, often with a modal like can or will).
Companies are developing sodium-ion batteries in order to reduce costs.
Engineers designed solid-state batteries with a solid electrolyte so that they would be safer.
A city might choose Na-ion for its buses so that they can operate reliably in the winter.
Use-Case Draft: Tech Trade-offs Challenge
Introduction E-Bikes Delivery Vans Grid Storage City Buses
Scenarios
Work in small groups of 3-4. Your team is a group of technology consultants. A local government has asked you to recommend a battery technology for one of the following projects.
- Choose one scenario from the tabs.
- Discuss the pros and cons of using Sodium-ion vs. Solid-state batteries for that scenario.
- Choose ONE technology.
- Prepare to explain your recommendation with at least two clear reasons. Use the language of comparison and purpose.
A fleet of e-bikes for a university campus. These bikes are used for short trips and must be reliable year-round.
A fleet of city delivery vans. These vans travel predictable routes every day and need to be cost-effective.
A grid storage facility. This facility stores excess energy from solar panels during the day and releases it at night to power the city.
A new fleet of public city buses. Safety is the top priority, and the buses must run all day without needing to stop for a long recharge.
Example: "We recommend sodium-ion batteries for the campus e-bikes. First, they are cheaper than solid-state, which is important for a public project. Second, their performance is better in the cold so that students can use the bikes reliably during the winter."
Panel: Recommendations & Questions
A few teams will now present their recommendations to the class.
- Presenters: Briefly state your chosen scenario, your recommendation, and your two reasons.
- Audience: Listen carefully. After the presentation, ask the presenters questions about the trade-offs of their choice. Think about:
- What about safety?
- What about the battery's lifespan (how many times it can be charged)?
- Where do the materials come from (sourcing)?
Exit: The Metric to Watch
Think about everything you've learned. If you were a journalist reporting on battery technology, which single metric would you watch most closely in the news in 2026? Be ready to share your answer and explain why.
- Cost per kilowatt-hour ($/kWh): The price of the battery.
- Energy Density (Wh/kg): The range of the vehicle.
- Cycle Life: The lifespan of the battery.
- Charging Speed: How fast it charges.