NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY
A non-aqueous electrolyte secondary battery is obtained by encasing, inside an outer casing formed of a laminate film, a power generating element containing a positive electrode obtained by forming, on the surface of a positive electrode current collector, a positive electrode active substance layer containing a positive electrode active substance, a negative electrode obtained by forming, on the surface of a negative electrode current collector, a negative electrode active substance layer containing a negative electrode active substance, and a separator, wherein the positive electrode active substance is made to contain a spinel type lithium manganese composite oxide and a lithium nickel-based composite oxide and the mixing ratio of the lithium nickel-based composite oxide is 30 to 70% by weight relative to the total 100% by weight of the spinel type lithium manganese composite oxide and the lithium nickel-based composite oxide.
1 . A non-aqueous electrolyte secondary battery obtained by encasing, inside an outer casing formed of a laminate film, a power generating element comprising:
a positive electrode obtained by forming, on the surface of a positive electrode current collector, a positive electrode active substance layer containing a positive electrode active substance;
a negative electrode obtained by forming, on the surface of a negative electrode current collector, a negative electrode active substance layer containing a negative electrode active substance; and
a separator, wherein
the positive electrode active substance contains LiMn 2 O 4 and a lithium-nickel-manganese-cobalt composite oxide, the mixing ratio of the lithium-nickel-manganese-cobalt composite oxide is 30 to 70% by weight relative to the total 100% by weight of LiMn 2 O 4 and the lithium-nickel-manganese-cobalt composite oxide, the ratio of the total amount of LiMn 2 O 4 and the lithium-nickel-manganese-cobalt composite oxide in 100% by weight of whole amount of the positive electrode active substance contained in the positive electrode active substance layer is 50% by weight or more, and the weight per unit area (single surface coating amount) of the negative electrode active substance layer is 7.4 to 9.2 mg/cm 2 and the thickness of the positive electrode active substance layer is 2 to 100 μm.
2 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein
the lithium-nickel-manganese-cobalt composite oxide has a composition represented by General Formula: Li a Ni b M c Co d O 2 (with the proviso that, in the formula, a, b, c, and d satisfy 0.9≦a≦1.2, 0<b<1, 0<c≦0.5, 0<d≦0.5, and b+c+d=1. M represents at least one selected from the group consisting of Mn, Ti, Zr, Nb, W, P, Al, Mg, V, Ca, Sr, and Cr).
3 . The non-aqueous electrolyte secondary battery according to claim 2 , wherein b, c and d are as follows: 0.44≦b≦0.51, 0.27≦c≦0.31, and 0.19≦d≦0.26.
4 . (canceled)
5 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the separator is a separator having a heat resistant insulating layer.
6 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the ratio value of a battery area (projected area of a battery including a battery outer casing) to rated capacity is 5 cm 2 /Ah or more and the rated capacity is 3 Ah or more.
7 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the aspect ratio of an electrode defined as a longitudinal/transversal ratio of a rectangular positive electrode active substance layer is 1 to 3.
8 . The non-aqueous electrolyte secondary battery according to claim 1 , wherein the laminate film is a laminate film containing aluminum.