Defect-rich potassium amide: A new solid-state potassium ion electrolyte

One of the major obstacles to the application of potassium-ion batteries in large-scale energy storage is the lack of safe and effective electrolytes. KNH 2 , a new potassium-ion solid electrolyte has been developed in this study. Its ionic conductivity reaches 4.84 × 10 −5  S cm −1 at 150 °C and can reach 3.56 × 10 −4  S cm −1 after mechanochemical treatment. The result from electron paramagnetic resonance (EPR) measurement shows that the increment of ionic conductivity is dependent on the concentration of nitrogen defects in the KNH 2 electrolyte. To the best of our knowledge, this is the first report that adopts inorganic amide as an electrolyte for potassium-ion battery and initiates the search for a new amide-based solid electrolyte for an all-solid-state potassium-ion battery.