Lithium and Sodium are closely related alkali metals in the periodic table of elements and, therefore, have similar properties and uses. One of the main differences is their weight; sodium molecules are heavier than lithium molecules.
The reason I am writing a blog about these elements it that the worldwide scarcity of Lithium, is raising a supply issue, as the demand for lithium batteries skyrockets. The fact that the best lithium batteries require layered-oxide cathodes and they, in turn, require cobalt and nickel, both also in short supply worldwide, also makes the supply problem worse. Cobalt is particularly difficult because the biggest deposit discovered so far, is in the Democratic Republic of Congo, where politics, human rights, and many other complicating factors abound. Also playing into the supply problem mix, on the political side, is the fact that China processes over 75% of the world’s lithium.
Enter Sodium. Sodium is plentiful through the world. It makes up most of the salt in the oceans, for example. In addition, layered-oxide cathodes which use sodium can get by without cobalt and nickel, unlike lithium. It almost begs the question of why the battery industry didn’t use sodium in the first place. The answer to that question is weight. A sodium battery delivering the same electrical capacity will be bigger and heavier than its lithium equivalent.
Weight and size matter in cell phone batteries, electric car batteries, and electric aircraft design, which is the reason those industries have emphasized lithium batteries over sodium ones, despite the significant cost advantage of sodium units. However, other large industries don’t have to worry so much about weight and size; examples would be electrical grid storage, home electrical storage, and heavy forms of transport, such as trucks and ships. These are areas not dramatically affected by battery weight and size.
The result is that, as the demand for batteries grows, and it is growing exponentially, scientists and companies are racing to develop sodium batteries for non-weight/non-size critical applications. Potentially, sodium batteries will be much cheaper, since the raw materials that go into them are abundant, which is another incentive to develop them.
Battery technologies are notorious for taking time to develop. They always seem to be way behind the demand for the entities they power; electric cars could have been built years ago, but the batteries would have been so heavy, those cars would hardly have been able to move. So, sodium batteries are not going to take over from lithium batteries any time soon. However, they represent a viable alternative in certain industries and applications. Sodium battery development industries are popping up in China, Sweden and in several other parts of the world. Some of these industries are subsidiaries of lithium battery industries, which raises a concern as to motivation: the world is full of companies buying competition in order to kill it. However, the sky-rocketing demand for battery power, and the scarcity of lithium battery components, probably makes that unlikely.
I would think that, if you are looking at a long-term investment, sodium battery companies might be a good, but risky, bet. Many will fall by the wayside as different engineering applications of the theory play out. Also, there is the possibility that the earth contains a lot more lithium, cobalt and nickel than we presently know about. A major discovery in that direction could completely scupper the concept of a sodium battery…….we’ll just have to watch this space.
In the meantime, sodium batteries are a fascinating idea those time might have come. Further, it represents a concept that is all too unusual in human technological development, and that’s balance. We tend to use something until it’s exhausted………and then think about replacing it. Developing lithium and sodium batteries together is a far more efficient way of using earth’s resources than purely “immediate-profit-driven” considerations.