Electrode for non-aqueous electrolyte secondary battery and production method thereof

Abstract

An electrode in sheet form includes a current collector and an electrode mixture layer carried on each side thereof. The electrode is bent in the longitudinal direction thereof, to cause a large number of cracks in at least the electrode mixture layer to be positioned on the inner side of the current collector when wound, such that the cracks extend from the surface of the electrode mixture layer to the current collector in the direction intersecting with the longitudinal direction of the electrode. This bending process includes the steps of: bending the electrode at a curvature that is smaller than that of the winding core at least once; and thereafter bending the electrode at a curvature that is equal to or larger than that of the winding core. For example, this process is performed by arranging rollers such that their diameters decrease gradually and pressing the electrode against these rollers. This invention provides an electrode that does not break when wound to form an electrode assembly.

1 . An electrode for a non-aqueous electrolyte secondary battery, comprising: a current collector; and an electrode mixture layer carried on each side of said current collector,
 said electrode being in sheet form and designed to be spirally wound onto a winding core together with an electrode of opposite polarity and a separator,   wherein at least the electrode mixture layer on the winding core side has a large number of cracks that extend from the surface of the electrode mixture layer to the current collector in the direction intersecting with the longitudinal direction of the electrode.   
   
   
       2 - 4 . (canceled) 
   
   
       5 . A non-aqueous electrolyte secondary battery comprising an electrode assembly, said electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, which are wound onto a winding core, wherein at least one of the positive electrode and the negative electrode is the electrode of  claim 1 .