Metal-Free High-Voltage Cathodes for Secondary Lithium-Ion and Alkali-Ion Batteries

An alkali-ion battery is provided that includes an anhydrous alkaline salt as an active cathode material, where the alkaline salt may be, for example, a lithium sulfate salt, sodium sulfate salt or potassium sulfate salt, as the active cathode material. In some such batteries, the inter-conversion of sulfate to persulfate occurs during charging and discharging of the battery, respectively.