This paper is about a leading technology in the manufacture of electric vehicles (EVs), and the title technology, a rapidly developing competitor. If you know anything about EVs, you’ve immediately guessed that the above “…leading technology…” is lithium-ion batteries, and you are correct. However, electric vehicles are not the only market that that uses these batteries, and one of them offers the first step up a ladder that may lead the new-comer to an entry-point into the EV market. Furthermore lithium-ion battery technology has some vulnerabilities, one of them very recent, very large, particularly with respect to sodium-ion batteries.