The battery of the future was constructed out of sodium half a century ago. This is why salty seas exist. One of the electrons in sodium is lost when it ionizes. These ions travel back and forth between plates that are oppositely charged, creating a current. This seemed like a promising way of powering a house or car. The party was halted by lithium, the upstairs neighbor of sodium on the periodic table. Sony released the first rechargeable lithium-ion batteries in 1991. They were small enough to be carried around with them and could power their handheld cameras. Because lithium was lighter than sodium and more easy to use, a whole industry grew around it. Research labs and companies raced to squeeze more energy into a smaller space. Sodium was left behind.
It was therefore surprising that China's CATL (one of the largest battery manufacturers in the world) announced this summer that sodium would play an important role in electrifying the future. Like its competitors, CATL is a lithium-based company. It will start putting sodium cells in the batteries that power electric cars starting in 2023. Why? One reason is that sodium is more affordable than lithium and it performs better in colder weather. It was also hedge against an issue that was hard to see in 1991. The world will run out of raw materials for batteries by the end this decade. This includes lithium and metals like nickel, cobalt, and others. It's time for diversification now that electrification has begun to happen on a large scale. WIRED was told by a spokesperson for CATL that the company began thinking about sodium in 2010
Shirley Meng, a University of California, San Diego battery scientist who has extensive experience working with both sodium and calcium, said that CATL's announcement "really instilled new energy in the people who work on it." Meng began working with sodium as a young professor because she wanted to find a niche that would make her stand out, but also because she believed it had the potential. Meng says that the biggest obstacle to sodium's success was lithium's success.
It is not uncommon to find lithium. However, deposits can be found in areas that are difficult to mine. CATL and other companies compete for a share of the limited supply of mines located mostly in Australia and the Andes. The US is concerned about the security and integrity of supply chains because North American reserves are being impacted by environmental disputes. Nickel is the most in-demand metal, and Elon Musk calls it the "biggest concern" regarding the future of EV batteries. This is due to supply and price constraints. Cobalt is also in high demand, with 70 percent of its resources being dug up by the Democratic Republic of the Congo.
Meng states that there will be more lithium available to power the world's cars as more mines are opened. However, this doesn't take into account all the other things that could be electrified. These include the batteries that manage the load in microgrids and keep the lights on at night even if the rooftop solar panels go dark. Meng was thinking of these kinds of applications when she started researching sodium. She says, "I thought everyone would have a refrigerator to store electrons in their home in the same manner you have a fridge for food." "I believe that's the vision for grid storage."