NOVELTY - A lithium ion secondary battery (20) has battery element (17) including positive electrode, electrolyte layer (13), negative electrode and cell layer (16). The positive electrode has positive electrode active material layer (12) containing active material, provided on surface of collector. The electrolyte layer contains electrolyte which consists of solution including lithium and cation of metallic element dissolved in organic solvent. The negative electrode active material contains group-XIII or group-XV elements doped with silicon.    USE - Lithium ion secondary battery is used as power supply for vehicle (claimed) e.g. car. Can also be used in electric vehicle, hybrid electric vehicle, mobile telephone and personal computer.    ADVANTAGE - The lithium secondary battery has reduced generation of shrinkage of active material during charging and discharging.    DETAILED DESCRIPTION - A lithium ion secondary battery has battery element including positive electrode, electrolyte layer negative electrode, and cell layer. The positive electrode has positive electrode active material layer containing active material, provided on surface of collector. The electrolyte layer contains electrolyte. The negative electrode has negative electrode active material layer (15) containing active material, provided on surface of collector. The cell layer is sequentially laminated with positive electrode active material layer, electrolyte layer and negative electrode active material layer, such that positive electrode active material layer and negative electrode active material layer are opposite to each other. The electrolyte contains solution including lithium, and cation of metallic element dissolved in organic solvent. The negative electrode active material contains group-XIII or group-XV elements doped with silicon.    DESCRIPTION OF DRAWING(S) - The drawing shows cross-sectional view of lithium ion secondary battery.    Lithium ion secondary battery (10)    Positive electrode active material layer (12)    Electrolyte layer (13)    Negative electrode active material layer (15)    Cell layer (16)    Battery element (17)