Batteries are an increasingly important technology to our civilization. If I could wave a magic wand and make one specific non-medical technology advance 10-20 years in a day, it would be battery technology. Batteries are used in our everyday devices, like phones and laptops. They are the single most critical factor to EVs, and they can provide grid storage which can make the adoption of low carbon energy much easier. Fortunately, battery technology is heavily researched and has been steadily increasing for the last few decades. We are now benefiting from this slow but cumulative improvement.

Having said this, we appear to still be close to tipping points that could make various industries significantly different with further battery improvements. EVs, in my opinion, are already good enough for prime time. They have great range, they are usually cheaper to own than ICE vehicles (a little more expensive up-front, but lower maintenance and fuel costs), and they have fantastic performance. Also, despite warning of battery fires, they are actually less likely to catch fire than gasoline vehicles.  But still there is a lot of resistance to ownership. Part of this is misinformation and unfounded fears, but there are some genuine limitations that battery advances could address. Batteries are still expensive, and the up-front cost of EVs will come down as batteries become cheaper. While fires are rare, they are serious because they cannot be put out. And EVs can lose significant range in very cold weather.

Although, the most significant issue that non-EV owners have with EVs is range anxiety. Most of this is just unfamiliarity with the technology. The ranges of most EVs are actually beyond what most people need. But there are two real issues that are infrastructure issues, not battery issues. We need more public fast chargers. If you live in a high population-density area, like along the coasts, there is no issue. But for many parts of the US, at least, public chargers are not yet of a sufficient density to allay fears that your EV battery will go dead while you are out in the sticks and far from a charger. The second issue is for people who do not own a private parking spot for their vehicle. This means we need more charging locations in garages and other places where people without private parking will park.

There is another issue, which does not have to do with the individual user but with the bigger picture of adopting EVs and intermittent energy and electrifying industries – there is a resource limitation for lithium to make lithium-ion batteries. There are potential fixes – such as mining the ocean – but these are a ways off and may never come to fruition. There is a possible solution, however – sodium-ion batteries. Lithium is the best salt for battery chemistry because Li is the lightest salt on the periodic table (3 protons). Nothing can ever beat it for theoretical best specific energy (energy storage per mass). Sodium (Na) is right below it at 11 protons, so it’s an obvious choice for a possible Li replacement. Sodium also has another feature which is actually a massive advantage over Li – it is very cheap and abundant. If we could make a Na-ion battery roughly as good as current Li-ion batteries, that would basically solve the resource problem with Li (although there could still be issues with other elements in the battery).

For this reason there has been a lot of research over the last decade into developing a commercial sodium battery. I have been following the research, and it has been encouraging, but still a future technology that we hope will work out some day. That day has likely arrived – it was actually back in April that CATL announced it has developed the first mass-produced sodium battery. They plan on starting mass production in December of this year, so in less than two months. That sounds great, but what are the critical stats. Here is what they say, which has been apparently validated by independent testing.

First, the specific energy will be 175Wh/kg, which is good, right in the middle of the Li-ion battery range. Depending on the specific chemistry used, Li batteries range from about 140 to 220Wh/kg. This is not an improvement in energy density or specific energy, more of a lateral move, and not as good as the best Li batteries. Also, the newer silicon anode Li-ion batteries from companies like Amprius have an energy density of up to 450Wh/kg. That is massive. They are marketing to electric planes, but plan on producing batteries for EVs soon, and other battery manufacturers will be coming out with their own silicon anode batteries. So this seems to be the future of high-end EV batteries. But they still suffer from the lithium shortage.

The CATL sodium batteries have a few other advantages. They are far less likely to catch fire that Li batteries. Also, they have a better operating temperature, maintaining 80% of their charge in up to -40 degrees and +70 degrees C. That is a great operating temperature range, and will make EVs much more viable in colder parts of the world. They also have a longer lifespan, rated at 10,000 cycles, which is far more than the lifetime of the average car. They can be fast-charged as fast ad Li batteries, and in fact can be charged faster with chargers designed to do so. And finally here is perhaps the biggest advantage – they will cost less than half as much as current Li-ion batteries. That is potentially huge, taking 5-10 thousand off the cost of the average EV.

What this likely means is that sodium batteries are likely to rapidly take over the low to mid range EV battery industry. The lower cost is just too much of an advantage. The batteries are safer and have a longer life and better temperature range to boot. We will then still have the Li-ion batteries for the high-end EV, soon to include the silicon anode batteries. So for larger vehicles or for those who want or need extreme range, Li will still be the way to go. This may change as sodium batteries improve further – we will have to see how the two competing technologies each advance.

For home energy storage and for grid storage sodium batteries are likely to completely displace lithium. Why pay a premium for lithium when specific energy and energy density does not matter that much.

This is all good news. We don’t want all our battery eggs in the same basket. This could take a lot of pressure off lithium supplies, keeping lithium for the high end uses where it is necessary (including electric planes). For most other battery uses, sodium is a cheaper and much more abundant alterative. There are also other battery options in development, many using cheap abundant materials and intended for grid storage (but not suitable for EVs). So it’s possible other battery types will come into the mix.