The answer seems to be that it is a misnomer or at least bad choice of name. They talk about (lithium) ionic superconductors at each occurence of the term super

The answer seems to be that it is a misnomer or at least bad choice of name. They talk about (lithium) ionic superconductors at each occurence of the term superconductor which makes me think that they actually mean materials that only let lithium ions through but not others (because this is how their device actually works). https://www.sciencedirect.com/science/article/pii/S0011916414006560 https://www.sciencedirect.com/science/article/pii/S001191641... (Open Access)