Enhanced charge-storage electrochemical double layer capacitors with nanoscale electrolyte confinement tunability, and a method for production thereof to obtain axi-symmetric, high surface area electrode growth

Abstract

An enhanced energy storage device such as double layer capacitor or battery is made starting with a substrate capable of conducting stored energy. The substrate material is one in which ordered pores can be formed, creating a template of densely arrayed pores. An electrode comprised of high density carbon nanotubes within the template is grown from and oriented substantially perpendicular to the substrate to constitute an axi-symmetric, ultra-high surface area electrode, and then the template is then selectively and only partially etched. An electrolyte is structurally confined anisotropically around the nanotubes by a remaining portion of the selectively and partially etched template so that substantially enhanced energy storage is obtained. The optimal structural confinement, which causes optimal charge storage, depends upon the amount of partial etching of the template which is defined by the electrolyte selected.