Nonaqueous electrolyte secondary battery

Abstract

The present invention provides a nonaqueous electrolyte secondary battery having high safety to reliably prevent the progress of successive heat generation when battery temperature rises caused by abnormalities such as internal short-circuits. The nonaqueous electrolyte secondary battery disclosed herein is provided with an electrode body 20 in which a sheet-shaped positive electrode 50 and a sheet-shaped negative electrode 60 oppose each other across separators 70. In the nonaqueous electrolyte secondary battery disclosed herein, the peel strength of a boundary A between each separator 70 and a positive electrode mix layer 54 is greater than the peel strength of a boundary B between the positive electrode mix layer 54 and a positive electrode collector 52. As a result, the progress of successive heat generation derived from an increase in reaction heat can be prevented by causing the positive electrode mix layer 54 to peel off the positive electrode collector 52 accompanying thermal deformation of the separators 70 when battery temperature rises for instance due to an internal short-circuit.

Dependencies are inferred from the claim text.