Non-aqueous electrolyte secondary battery

摘要

To improve high temperature storage characteristic of a non-aqueous electrolyte secondary battery suitable for high input/output application, the structure of a positive electrode active material is optimized. The non-aqueous electrolyte secondary battery includes a positive electrode; a negative electrode; a separator interposed between the positive and negative electrodes; and a non-aqueous electrolyte. The positive electrode active material includes secondary particles, each formed of an aggregate of primary particles. A value (VPr) defined by the formula: VPr=(1−C/D)/(A2×B3) is not less than 0.0005 and not greater than 0.04, where an average particle size of the primary particles is A μm, an average particle size of the positive electrode active material is B μm, a tap density of the positive electrode active material is C g/ml, and a true specific gravity of the positive electrode active material is D g/ml.

主权项

1. 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; a separator interposed between said positive electrode and said negative electrode; and a non-aqueous electrolyte, wherein said positive electrode active material comprises secondary particles, each comprising an aggregate of primary particles, said primary particles comprising a transition metal-containing composite oxide capable of intercalating and deintercalating lithium ions, and wherein a value (VPr) defined by the formula:VPr=(1−C/D)/(A2×B3), is not less than 0.0005 and not greater than 0.04,
where an average particle size of said primary particles is A μm, an average particle size of said positive electrode active material is B μm, a tap density of said positive electrode active material is C g/ml, and a true density of said positive electrode active material is D g/ml, provided that C is from 2.4 to 2.6, wherein, said composite oxide is represented by the formula: LixNi1-(y+z)CoyMzO2, where 1.01≦x≦1.05, 0.1≦y≦0.2, and 0.02≦z≦0.1, and said element M represents Al.