This study presents high-entropy spinel oxide ferrites (HESO) as promising conversion anode materials for lithium-ion batteries (LIBs). Four different HESO compositions, each containing five or six metals, were synthesized via a rapid combustion method and evaluated in lithium half-cells. These materials exhibited significantly superior electrochemical performance compared to conventional spinel ferrites like Fe₃O₄ and MgFe₂O₄, maintaining capacities above 600 mAh g⁻¹ for 150 cycles. X-ray absorption spectroscopy (XAS) revealed that Fe, Co, Ni, and Cu were reduced to the elemental state during lithiation, while Mn was only slightly reduced. Upon delithiation, Fe was reoxidized to an average oxidation state of about 2.6+, while Co, Ni, and Cu remained in the metallic state. The high capacity of these materials is attributed to the ability of Fe to be oxidized beyond 2+ and the presence of metallic elements that provide an electronically conductive network. The HESOs were synthesized using a solution combustion method, resulting in highly crystalline materials with a cubic inverse spinel structure. Structural characterization using synchrotron X-ray diffraction and XAS confirmed the high crystallinity and composition of the materials. The electrochemical performance of the HESOs was evaluated through galvanostatic cycling, showing high reversible capacity, stable capacity retention, and rapid rate capability. The XAS analysis of the pristine, discharged, and charged electrodes revealed the oxidation states of the metals, with Fe, Co, Ni, and Cu being reduced to the elemental state during lithiation and reoxidized upon delithiation. The Mn oxidation state was determined to be around 2.0. The results indicate that the redox activity of Fe centers is responsible for the high capacity of the HESOs, while the presence of metallic components contributes to the overall electrochemical performance. The study highlights the potential of HESOs as high-performance conversion anode materials for LIBs due to their superior electrochemical properties and ability to oxidize Fe beyond 2+.This study presents high-entropy spinel oxide ferrites (HESO) as promising conversion anode materials for lithium-ion batteries (LIBs). Four different HESO compositions, each containing five or six metals, were synthesized via a rapid combustion method and evaluated in lithium half-cells. These materials exhibited significantly superior electrochemical performance compared to conventional spinel ferrites like Fe₃O₄ and MgFe₂O₄, maintaining capacities above 600 mAh g⁻¹ for 150 cycles. X-ray absorption spectroscopy (XAS) revealed that Fe, Co, Ni, and Cu were reduced to the elemental state during lithiation, while Mn was only slightly reduced. Upon delithiation, Fe was reoxidized to an average oxidation state of about 2.6+, while Co, Ni, and Cu remained in the metallic state. The high capacity of these materials is attributed to the ability of Fe to be oxidized beyond 2+ and the presence of metallic elements that provide an electronically conductive network. The HESOs were synthesized using a solution combustion method, resulting in highly crystalline materials with a cubic inverse spinel structure. Structural characterization using synchrotron X-ray diffraction and XAS confirmed the high crystallinity and composition of the materials. The electrochemical performance of the HESOs was evaluated through galvanostatic cycling, showing high reversible capacity, stable capacity retention, and rapid rate capability. The XAS analysis of the pristine, discharged, and charged electrodes revealed the oxidation states of the metals, with Fe, Co, Ni, and Cu being reduced to the elemental state during lithiation and reoxidized upon delithiation. The Mn oxidation state was determined to be around 2.0. The results indicate that the redox activity of Fe centers is responsible for the high capacity of the HESOs, while the presence of metallic components contributes to the overall electrochemical performance. The study highlights the potential of HESOs as high-performance conversion anode materials for LIBs due to their superior electrochemical properties and ability to oxidize Fe beyond 2+.