▎ 摘　　要

NOVELTY - The power storage device has a negative electrode and a positive electrode. The negative electrode includes a current collector and an active material layer. The active material layer includes active material particles (121) and a graphene compound (123) and a binder (122) that cover the active material particles. Each space (124,125) is present between the active material particle, and the graphene compound and the binder. The particles comprise silicon. The binder comprises polyimide. USE - Power storage device for electronic device (claimed). Uses include but are not limited to, e.g., portable information terminals such as mobile phones, smartphones, and laptop computers, portable music players, and digital cameras, medical equipment, as well as next-generation clean energy vehicles such as hybrid electric vehicles (HEVs), electric vehicles (EVs), and plug-in hybrid electric vehicles (PHEVs). ADVANTAGE - Increased lifetime of a storage battery can reduce the frequency of battery changes and improve the convenience of a device provided with the storage battery. A conductive graphene compound has excellent electrical characteristics of high conductivity and excellent physical properties of high flexibility and high mechanical strength. The positive temperature coefficient (PTC) element, which serves as a thermally sensitive resistor whose resistance increases as temperature rises, limits the amount of current by increasing the resistance, in order to prevent abnormal heat generation. The power storage device itself can be made more compact and lightweight as a result of improved characteristics, such as high capacity and high energy density. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for an electronic device. DESCRIPTION OF DRAWING(S) - The drawing shows the cross-sectional view of an electrode. Active material particles (121) Binder (122) Graphene compound (123) Spaces (124,125)