NOVELTY - A nonaqueous electrolyte secondary battery has an exterior component which accommodates an electrode component and an electrolyte. The electrode component is obtained by winding or laminating a positive electrode (21) and a negative electrode (22) through a separator (24). The positive electrode contains positive electrode active material (21B) covered with phosphate. The electrolyte contains electrolyte solution contains a nonaqueous solvent, an electrolytic salt, and an isocyanate compound (I), (II), (III) or (IV).    USE - Nonaqueous electrolyte secondary battery. Uses include but are not limited to camcorder, digital still camera, mobile telephone, handheld terminal and notebook-type computer.    ADVANTAGE - The nonaqueous electrolyte secondary battery has excellent swelling inhibitory effect.    DETAILED DESCRIPTION - A nonaqueous electrolyte secondary battery has an exterior component which accommodates an electrode component and an electrolyte. The electrode component is obtained by winding or laminating a positive electrode and a negative electrode through a separator. The positive electrode contains positive electrode active material covered with phosphate. The electrolyte solution contains a nonaqueous solvent, an electrolytic salt, and an isocyanate compound of formula: R1-N(=C)(=O) (I), of formula: O=C=N-R2-N=C=O (II), of formula: R3-N=C=O (III), or of formula: O=C=N-R4-N=C=O (IV).    R1,R2=1-22C linear hydrocarbyl optionally substituted by halo, oxygen, sulfur, nitrogen or silicon;and    R3,R4=3-20C cyclic hydrocarbyl optionally substituted by halo, oxygen, sulfur, nitrogen or silicon.    An INDEPENDENT CLAIM is included for manufacture of the nonaqueous electrolyte secondary battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a battery element of the nonaqueous electrolyte secondary battery. (Drawing includes non-English language text)    Battery element (20)    Positive electrode (21)    Positive electrode active material (21B)    Negative electrode (22)    Separator (24)