Patent ID: 9698414
Date: 2017-07-04
CPC Classifications: H01M,Y02E,Y02P

Claim:
1. A non-aqueous electrolyte secondary battery, comprising: a positive electrode composite material layer containing a ratio of said second positive electrode active material particles in a total mass of said first positive electrode active material particles and said second positive electrode active material particles being not lower than 5 mass % and not higher than 20 mass %, and an average of a standard deviation σ of 10 different square measurement regions (MR) chosen at random satisfies a condition of 0.28≦σ≦0.52, wherein the standard deviation of each square MR is calculated in the following expression (1): when a distribution of an iron element is determined by extracting a square measurement region of which one side has a length 0.95 times as large as a thickness of said positive electrode composite material layer from a cross-section of said positive electrode composite material layer in parallel to a direction of thickness of said positive electrode composite material layer and conducting area analysis with an electron probe microanalyzer in said measurement region, where z