▎ 摘　　要

NOVELTY - A graphene comprises 90-98 atomic% carbon atoms and 2-10 atomic% oxygen atoms, when measured using X-ray photoelectron spectroscopy. The content of sp2-bonded carbon atoms in the carbon atoms of graphene is 50-80%, when measured using X-ray photoelectron spectroscopy. USE - Graphene is used for forming electrode used in manufacture of power storage device (all claimed) e.g. lithium primary battery, lithium-ion secondary battery, and lithium-ion capacitor. Can also be used for display device, light-emitting device, field-effect transistor, sensor, and solar cell. ADVANTAGE - The graphene has high conductivity and mobility, and provides power storage device with excellent reliability, durability, and charge and discharge characteristics. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) electrode, which consists of a current collector and an active material layer containing graphene and active material particles; (2) power storage device, which consists of the electrode as positive electrode or negative electrode; (3) formation of graphene, which involves forming (S131) slurry containing graphene oxide, forming (S132) a layer containing graphene oxide using the slurry, performing (S134) chemical reduction process as primary reduction treatment with respect to graphene oxide in the layer, and performing (S137) thermal reduction process as secondary reduction treatment with respect to graphene oxide in the layer; (4) formation of electrode, which involves forming slurry containing graphene oxide and active material particles, forming a layer containing graphene oxide and active material particles on current collector using the slurry, performing chemical reduction process with respect to graphene oxide in the layer, and performing thermal reduction process with respect to graphene oxide in the layer; and (5) manufacture of power storage device, which involves forming the electrode. DESCRIPTION OF DRAWING(S) - The drawing shows the flowchart for formation of graphene-containing layer. Formation of slurry (S131) Formation of layer containing graphene oxide (S132) Evaporation process (S133) Chemical reduction process (S134) Thermal reduction process (S137)