Battery, electrode, and current collector used therefor

摘要

The present invention relates to a current collector including a base portion with a flat face, primary projections projecting from the flat face, and secondary projections projecting from the top of the primary projections. The present invention also relates to a current collector including a base portion with a flat face and primary projections projecting from the flat face, wherein the roughening rate of the top of the primary projections is 3 to 20. By using such a current collector, separation of the active material from the current collector can be inhibited when using an active material that has a high capacity but undergoes a large expansion at the time of lithium ion absorption.