Nonaqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery, comprising:

• a positive electrode including a positive electrode active material;
• a negative electrode including a negative electrode active material;
• and
• a separator that separates the positive electrode from the negative electrode, wherein
• the positive electrode active material contains a lithium-transition metal composite oxide represented by the general formula LiaNixCoyMzO2−b, wherein 0.95≤a≤1.05, 0.80≤x≤0.95, 0≤y≤0.20, 0≤z≤0.20, 0≤b≤0.05, x+y+z=1, and M represents at least one element selected from the group consisting of Al, Mn, Fe, Ti, Si, Nb, Mo, W, and Zn, the negative electrode active material contains a silicon material at greater than or equal to 1 mass % based on a total mass of the negative electrode active material, the separator has a substrate layer and a filler layer formed on a surface of the substrate layer,
• the filler layer faces the positive electrode, and includes a resin comprising an amide bond and includes a filler,
• the resin comprising an amide bond includes:
• a block A having a unit composed of 4,4′-diphenylsulfonylterephthalamide as a main component;
• and
• a block B having a unit composed of paraphenyleneterephthalamide as a main component,
• the unit composed of 4,4′-diphenylsulfonylterephthalamide accounts for greater than or equal to 30% and less than or equal to 70% in all units,
• a content of the filler in the filler layer is greater than or equal to 20 mass % and less than or equal to 90 mass % based on a total mass of the filler layer, and
• when 1 μl of propylene carbonate is dropped on the filler layer, a contact angle after one second is less than or equal to 10°.