SUPERCONDUCTING SOLID STATE ELECTROLYTES WITH LOW ACTIVATION ENERGY

An electrochemical cell includes electrolyte includes a cathode, an anode, and an inorganic boron cluster solid state electrolyte that has a metal cation selected from the group consisting of Li, Na, K, Mg, Ca, Zn, and Al, a composite salt mixture includes between 0.975 and 0.05 mole fraction of a first boron cluster salt and between 0.025 and 0.95 mole fraction of a second boron cluster salt. In some variations the composite salt mixture includes a third boron cluster salt and can have an activation energy less than 0.65 eV at one or more temperatures above -30C. The electrochemical cell can also include a catholyte, an anolyte, and/or a separator, and the catholyte, the anolyte, and/or the separator can include the inorganic boron cluster solid state electrolyte.