ENERGY STORAGE DEVICE AND METHOD FOR MANUFACTURING ENERGY STORAGE DEVICE

An aspect of the present invention is an energy storage device including an electrode assembly that has a negative electrode and a positive electrode, where the negative electrode contains a negative electrode substrate and a negative active material, and has a negative active material layer disposed in an unpressed shape along at least one surface of the negative electrode substrate, the negative active material includes solid graphite particles as a main component, and the solid graphite particles have an aspect ratio of 1 or more and 5 or less.