These lithium-cesium compounds are mind-boggling and super neat.
Probably worth noting, for anyone who visits this page, that what's going on here is that these are compounds being formed under very high pressures. High pressures (on the order of millions of atmospheres) change the electronegativity of elements, resulting in bonding behavior and electrochemical properties that seem highly unusual for those of us familiar with chemical properties at roughly 1 atmosphere.
That article links the following article which talks more about how electronegativity becomes totally wonky under high pressures: https://phys.org/news/2022-03-weird-world-high-pressure-chemistry-simple.html Sidenote: Apparently everything becomes a metal if you press it hard enough. Well, really really hard enough.
As for the superconductivity, it is currently a predicted property of these lithium-cesium compounds when they are also cooled to very low temperatures.