  Recently, electrides have received increasing attention due to their
multifunctional properties as superconducting, catalytic, insulating, and
electrode materials, with potential to offer other performance and possess
novel physical states. This work uncovers that Li$_5$N as an electride possess
four novel physical states simultaneously: electride state, super-coordinated
state, superconducting state, and superionic state. By obtaining high-pressure
phase diagrams of the Li-N system at 150-350 GPa using a crystal structure
search algorithm, we find that Li$_5$N can remain stable as P6/mmm structure
and has a 14-fold super-coordination number, as verified by Bader charge and
electron localization function analysis. Aditionally, we find that its
superconducting transition temperature decreases continuously with increasing
pressure, contrary to the behavior of most high-pressure superconducting
materials. Its superconducting transition temperature reaches the highest among
all known electride at 150 GPa (Tc = 48.97 K). Besides, Li$_5$N exhibits the
superionic state at 3000 K, in which N atoms act like solid, while some Li
atoms flow like liquid. The above results are further verified at a macroscopic
level by using deep learning potential molecular dynamics simulations.
