Copper–silicon core–shell nanotube arrays for free-standing lithium ion battery anodes

A free-standing and binder-free ultrathin (around 10 μm) 1D structured anode was reported, which was the first time copper–silicon core–shell nanotube arrays were fabricated using silicon nanowire arrays as the template. Within this design, cone-shaped copper nanotube arrays act as both the supporter of amorphous silicon and the current collector for the electrode.