NEGATIVE ELECTRODE ACTIVE MATERIAL AND USE OF SAME

This invention relates to an anode active material comprising at least one iron oxide selected from the group consisting of amorphous iron oxides, ferrihydrite, and lepidocrocite. The invention also relates to a lithium ion secondary battery anode material comprising the anode active material as a constituent component, a lithium ion secondary battery anode comprising the lithium ion secondary battery anode material, and a lithium ion secondary battery comprising the lithium ion secondary battery anode.