NOVELTY - A secondary battery has a positive electrode active material having lithium, manganese, cobalt, nickel, iron, chromium and/or copper, and lithium, boron, sodium, magnesium, aluminum, titanium, silicon, phosphorus and/or calcium, and a nonaqueous electrolyte containing boron-containing compound (II) and cyclic sulfonate ester. The amount of boron-containing compound (II) in nonaqueous electrolyte is 0.1-2 %mass.    USE - Secondary battery e.g. laminated-type secondary battery (claimed). Uses include but are not limited to power supply for mobile telephone, notebook computer, electric vehicle, etc.    ADVANTAGE - The secondary battery has high charging and discharging efficiency, and high capacitance maintenance factor.    DETAILED DESCRIPTION - A secondary battery has a positive electrode active material having compositional formula: Lia(MxMn2-x-yAy)(O4-wZw) (I), and a nonaqueous electrolyte containing boron-containing compound of formula (II) and cyclic sulfonate ester. The amount of boron-containing compound (II) in nonaqueous electrolyte is 0.1-2 %mass.    x=0.4-1.2;    y=0 or more;    x+y=less than 2;    a=0-1.2;    w=0-1;    M=cobalt, nickel, iron, chromium and/or copper;    A=lithium, boron, sodium, magnesium, aluminum, titanium, silicon, phosphorus and/or calcium;    Z=F or Cl;    Z1=halo, 1-10C perfluoroalkyl, XR1 or 1-10C alkyl or 4-20C cyclic hydrocarbyl (both optionally substituted);    X=O, S or NR2;    R2=H or optionally substituted 1-10C alkyl;    R1=optionally substituted 4-20C cyclic hydrocarbyl;    A1,A2=O, S or A1 is NR3 and A2 is NR4;    R3,R4=H, halo or 1-10C alkyl, 1-10C polyfluoroalkyl or 4-20C cyclic hydrocarbyl (all optionally substituted);    R3+R4=ring;    B1,B2=carbonyl, optionally substituted alkylene or polyfluoro alkylene;    L1=methylene or single bond;    m=1 or 2;    n=0 or 2;and    2m+n=4.    An INDEPENDENT CLAIM is included for manufacture of secondary battery, which involves assembling the positive electrode active material and the nonaqueous electrolyte.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of secondary battery.    Positive electrode active material layer (1)    Negative electrode active material layer (2)    Positive electrode collector (3)    Negative electrode collector (4)    Separator (5)