Nonaqueous electrolyte secondary battery
Provided is a nonaqueous electrolyte secondary battery that includes a laminate film exterior container housing an electrode body and an electrolyte solution. In the nonaqueous electrolyte secondary battery, the electrode body includes a positive electrode, a negative electrode, and a separator. The positive electrode includes a positive electrode active material layer formed on a positive electrode current collector. The negative electrode includes a negative electrode active material layer formed on a negative electrode current collector. The positive electrode active material layer includes secondary particles of a lithium nickel cobalt manganese composite oxide. The secondary particle includes a group of primary particles of a lithium nickel cobalt manganese composite oxide with a layered crystal structure. The primary particle has a cross-sectional area of 1.50 μm 2 or less. The layered crystal structure has a lattice constant “c” of 14.240 Å or less.
1. A nonaqueous electrolyte secondary battery comprising:
an electrode body;
an electrolyte solution; and
a laminate film package container housing the electrode body and the electrolyte solution, wherein
the laminate film package comprises a metal layer, a heat-seal layer, and a protective layer;
the electrode body includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode,
the positive electrode includes a positive electrode current collector, and a positive electrode active material layer formed on the positive electrode current collector,
the negative electrode includes a negative electrode current collector, and a negative electrode active material layer formed on the negative electrode current collector,
the positive electrode active material layer includes secondary particles of a lithium nickel cobalt manganese composite oxide,
the secondary particle includes a group of primary particles of a lithium nickel cobalt manganese composite oxide with a layered crystal structure,
the primary particle has an average cross-sectional area of 0.80 μm 2 or greater and 1.20 μm 2 or less,
the layered crystal structure has a lattice constant “c” of 14.240 Å or less, and
the lithium nickel cobalt manganese composite oxide is represented by the following Formula (1):
Li 1-x Ni a Co b Mn c O 2 (1)
wherein “x” satisfies 0≤x≤1, “a” satisfies 0.4≤a≤0.8, “b” satisfies 0.1≤b≤0.4, and “c” satisfies 0.1≤c≤0.5.
2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the layered crystal structure has a lattice constant “c” of 14.226 Å or more.
3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the layered crystal structure has a unit lattice volume of 101.60 Å 3 or less.
4. The nonaqueous electrolyte secondary battery according to claim 3 , wherein the layered crystal structure has a unit lattice volume of 101.20 Å 3 or more.
5. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the electrode body includes a positive electrode flat plate as the positive electrode and a negative electrode flat plate as the negative electrode.