Ferrate is considered to be a potential cathode material for high-energy batteries, due to its high capacity based on three-electron transfer in electrochemical reactions. In this work, high-purity potassium ferrate (K2FeO4) was synthesized by a direct hypochlorite oxidation method. X-ray diffraction (XRD) and a charge-coupled device (CCD) were used to characterize the structure of the K2FeO4 as well as the channels for intercalation–deintercalation of Li ions. The one-dimension channel was observed in the direction of the a and b axes in the unit cell, with a radius 0.93Å, which is beneficial for Li ion (radius=0.76Å) intercalation and deintercalation in K2FeO4. The experimental super-iron Li ion battery was assembled with 1M LiPF6 organic electrolyte (PC:EC:DMC=1:3:6, v/v), a K2FeO4 cathode, and a metal lithium anode. The electrochemical performance of the K2FeO4 cathode was evaluated by a galvanostatic method and cyclic voltammetry (CV) in the potential range of 4.3–0.5V at room temperature. It was demonstrated that one Li ion intercalates into the lattice of the K2FeO4 cathode along the channels of the a and b axes of the K2FeO4 unit cell, followed by a two-Li ion intercalation of isotropy in the initial discharge process. Amorphization of the K2FeO4 cathode is the main cause of its electrochemical performance decay.