A lithium-ion rechargeable battery (1) including: a battery unit (50) including a metal substrate (5) and a battery part (10) formed on a surface of the substrate (5); and a shell (30) for housing the battery part (10) in the interior thereof. The shell (30) includes a laminated film (31) that includes a metal layer (313) and a thermo-adhesive resin layer (315), the metal layer (313) is connected to a negative electrode collector layer (14) of the battery part (10), the substrate (5) functions as a positive external electrode of the battery part (10), and the metal layer (313) functions as a negative external electrode of the battery part (10).