Winding device and material winding method

A material winding method, comprising:

• winding plural layers of a material around a first winding pin on a winding switching mechanism;
• laminating and compounding the plural layers of the material at a preset position;
• rotating a rotating disc of the winding switching mechanism to switch winding of the plural layers of the material to a second winding pin, a compounding region of the plural layers of the material being located between the first winding pin and the second winding pin;
• and
• breaking the material at the compounding region of the plural layers of the material.

A jelly roll, formed by winding a plurality of layers of a material, wherein

• the plurality of layers of the material are provided with a compounding portion,
• the plurality of layers of the material are laminated and compounded together at the compounding portion, and a predetermined distance exists between the compounding portion and an end portion of the material in a winding direction;
• and
• the end portion is an end of an innermost circle of the material in the winding direction, or the end portion is an end of an outermost circle of the material in the winding direction.