Method and device for manufacturing lithium-ion secondary battery

When an insulating material from which a separator is to be formed is coated by a slit die coater on a coated electrode of a lithium-ion secondary battery, since a mixed layer is formed at the interface between an electrode material and the insulating material, failure risk due to short circuit becomes higher as the insulating material becomes thinner. Proposed is a method for manufacturing a lithium-ion secondary battery as a means for solving the above problem. In the method, an electrode sheet is manufactured in such a way that: an electrode material is coated by a slit die coater on an electrode substrate supplied at a predetermined speed; at the downstream, an insulating material is coated by a curtain coater on the electrode material layer formed on the electrode substrate; and subsequently both the electrode and insulating material layers are dried and firmly fixed in a drying furnace.