High energy density matters a lot for electric vehicles but very little for stationary grid-tied storage, so many more chemistries are potentially viable for grid tied storage. The really interesting question is whether one or more of them will reach sufficient volume to overcome the head start of lithium ion.
A lot of thin film solar PV companies were quite sure that their costs would be lower than the incumbent, crystalline silicon, once the manufacturing volume got high enough. Most went bankrupt because their manufacturing volume never grew fast enough for their designs' advantages to overcome the handicap of smaller scale production. Tesla's chemistry uses cobalt, which is expensive, but I don't know if low raw material costs alone are enough for (e.g.) sodium ion batteries to win over something like lithium iron phosphate batteries.
I'd imagine there's all types of companies trying to solve this in different ways.