| abstract |
A current collector substrate and an undercoat layer formed on at least one surface of the current collector substrate, the undercoat layer includes carbon nanotubes, and a basis weight per surface of the current collector substrate is: An undercoat foil for an energy storage device electrode of 0.1 g / m 2 or less. Since this undercoat foil can be efficiently ultrasonically welded, the use of this undercoat foil can provide a low-resistance energy storage device and a simple and efficient manufacturing method thereof. |