▎ 摘　　要

NOVELTY - Electrode (210) comprises an active material and a graphene compound comprising a graphene layer (213) and an optionally substituted chain group, where the graphene layer is bonded to the chain group through a substituent containing silicon, the active material is in particle form, and the graphene compound comprises a region (230) in contact with the active material. USE - The electrode is useful in a power storage device (claimed) including a secondary battery e.g. a lithium ion battery, an electrochemical capacitor e.g. an electric double-layer capacitor or a redox capacitor, an air battery, and a fuel battery. ADVANTAGE - The electrode: exhibits less deterioration and a high capacity; provides the power storage device which exhibits a long-life, less deterioration, high energy density and highly reliability; provides lithium ion secondary battery having a high operating voltage; and utilizes graphene which is formed by using graphite which exhibits a relatively high capacity per unit volume and relatively small volume expansion, is low in cost, and exhibits higher level of safety than that of a lithium metal. DETAILED DESCRIPTION - Electrode (210) comprises an active material and a graphene compound comprising a graphene layer (213) and an optionally substituted chain group, where the graphene layer is bonded to the chain group through a substituent containing silicon, the active material is in particle form, the graphene compound comprises a region (230) in contact with the active material, the active material comprises an element A1 and an element M1, the element A1 is at least one element comprising elements belonging to Group 1 or elements belonging to Group 2, the element M1 is at least one element comprising manganese or nickel, the chain group comprises at least one group comprising a carbonyl group, an ester group, a carboxy group, an ether group or an epoxy group. An INDEPENDENT CLAIM is also included for a power storage device comprising the electrode as a positive electrode, an exterior, an electrolyte solution, a separator and a negative electrode. DESCRIPTION OF DRAWING(S) - The figure shows a cross section of an electrode. Electrode (210) Current collector (211) Active material layer (212) Layer over the active material layer (213) Region (230)