Secondary battery, method and device for testing the negative electrode, and method and device for producing negative electrode thereof

摘要

In a method for testing a negative electrode of a secondary battery, light is irradiate to an active material layer formed on a current collector having a plurality of projections at least on one side thereof, the active material layer including first columnar bodies of active material grown obliquely from the projections. The angle is measured between the reflected light from the active material layer and a normal line parallel to the thickness direction of the current collector.