<p>βLiFe₅O₈/C, synthesized by a one-step phase conversion from P4₃32 space group α-LiFe₅O₈, exhibited Fd-3&#xa0;m space group and demonstrated an extraordinary capacity of 516 mAh g^− 1 with a Coulombic efficiency exceeding 99% following 1800 cycles at 1&#xa0;A g^− 1. The calculated diffusion coefficient of β-LiFe₅O₈/C was within the range of approximately 10^− 10 to 10^− 12 cm² s^− 1. The conversion mechanism was further extended based on the preceding research of α-LiFe₅O₈ during the discharge process. It was postulated that during the initial discharge of the material, with one mole of lithium ion intercalation in the unit formulation, β-LiFe₅O₈ underwent decomposition into LiFeO₂ and Fe₃O₄. Subsequent discharge was the conversion of LiFeO₂ and Fe₃O₄ to the metal Fe and Li₂O. The formation of Fe₃O₄ during charging was detected by using ex-situ Transmission Electron Microscope. Therefore, the system underwent a cycle between the fully charged state of Fe₃O₄ and the fully discharged state of metallic Fe and Li₂O thereafter.</p> Graphical Abstract <p></p>