ENERGY STORAGE DEVICE AND METHOD OF PRODUCING THE SAME

摘要

When manufacturing an energy storage device of a lithium ion battery or the like, the present invention provides an energy storage device which can solve a problem of modification or insulation that can be occurred in a separator, and has excellent durability and reliability. The energy storage device (100) comprises: a positive electrode (10) having a positive composite layer (12) including a positive electrode active material; a negative electrode (20) having a negative electrode composite layer (22) including a negative electrode active material; and a separator (30) for separating the positive electrode (10) and the negative electrode (20). The separator (30) includes: a sheet substrate (31) uniaxially elongated; and a cladding layer (32) for cladding any one surface of the substrate (31). The cladding layer (32) has an anisotropic structure aligned in a direction different from an elongation direction of the substrate (31).