Abstract: The present invention is a secondary battery comprising the package shell, secondary battery core component and electrolyte. The package shell is made of the print circuit board (PCB) material and encloses the secondary battery core component. The electrolyte is filled inside the enclosed space of package shell. The secondary battery core component comprises the positive electrode, isolation membrane and negative electrode, all laminated in sequence from top to down. The positive electrode comprises at least the first substrate which is respectively covered by the first thin metal layers on both the top side and bottom side. The negative electrode comprises at least the second substrate which is respectively covered by the second thin metal layers on the top side and bottom side.