NOVELTY - A nonaqueous electrolyte secondary battery consists of a stacked electrode assembly (15) formed by stacking layers of a positive electrode plate (1) and layers of a negative electrode plate (2) with separators (30,32) interposed in between, and an outer component accommodating the stacked electrode assembly and a nonaqueous electrolyte. The outer component is formed using a laminated film. The nonaqueous electrolyte contains lithium bis(oxalato)borate and/or a boron-containing substance derived from lithium bis(oxalato)borate.    USE - Nonaqueous electrolyte secondary battery e.g. lithium ion secondary battery, is used for electric vehicles and hybrid electric vehicles.    ADVANTAGE - The nonaqueous electrolyte secondary battery is environmentally-friendly, has excellent charging/discharging characteristics, and improves driving performance, such as accelerating performance and hill-climbing performance. Degradation of driving performance even in severe environment (usage in very cold areas and very hot areas) is prevented.    DETAILED DESCRIPTION - A nonaqueous electrolyte secondary battery consists of a stacked electrode assembly formed by stacking layers of a positive electrode plate and layers of a negative electrode plate with a separator interposed in between, and an outer component accommodating the stacked electrode assembly and a nonaqueous electrolyte. The outer component is formed using a laminated film. The nonaqueous electrolyte contains lithium bis(oxalato)borate and/or a boron-containing substance derived from lithium bis(oxalato)borate. Each of the positive electrode plate and the negative electrode plate having an area of 100 cm2 or more. The stacked electrode assembly has a thickness in the stacking direction of 10 mm or less.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the stacked electrode assembly.    Positive electrode plate (1)    Negative electrode plate (2)    Stacked electrode assembly (15)    Separators (30,32)    Electrode plates (40a,40b)