> But I was under the impression that the main stumbling block for molten salt reactors was that high-energy corrosion resistant materials for containing / moving molten salt simply don't exist (yet).

Is this also an issue for molten salt / liquid metal batteries[1][2] that have been proposed as a grid scale energy storage solution for renewables?

The way I understand it, molten salt is used as the membrane separating the electrode and electrolyte layers. But I was under the impression that there are actual molten salt batteries prototypes with industrial scale facilities currently under construction.

Are the requirements to contain the molten salt in a battery different from a nuclear reactors? Or do they have the same challenges and are simply able to overcome economic feasibility whereas nuclear reactors aren’t?

1: https://ambri.com/

2: https://www.youtube.com/watch?v=-PL32ea0MqM