Patent ID: 7238449

Claim:
A nonaqueous electrolyte secondary battery having an electrode assembly which is arranged, together with a nonaqueous electrolyte containing a lithium salt, in a sealed container, said electrode assembly being composed of a positive electrode and a negative electrode which are laminated one over another with a separator interposed between them, said positive electrode being formed into a sheet from a positive electrode mix prepared mainly from a boronized graphitic material containing boron or a boron compound such that the content of boron therein is 0.05-11 wt %, the boronized graphitic material being involved in charging-discharging reaction, said negative electrode being formed into a sheet from a negative electrode mix prepared mainly from a carbonaceous material capable of occluding and releasing lithium, wherein the positive electrode and the negative electrode are arranged, with a separator interposed between them, in such a way that the periphery of the plane of the negative electrode facing to the positive electrode, said plane being projected to the plane of the positive electrode facing to the negative electrode, is surrounded by the periphery of the plane of the positive electrode facing to the negative electrode.