Embodiments described herein generally relate to methods and apparatus for forming an electrode structure used in an energy storage device. More particularly, embodiments described herein relate to methods and apparatus for characterizing nanomaterials used in forming high capacity electrode structures for energy storage devices. In one embodiment a process for forming an electrode structure for an energy storage device is provided. The process comprises depositing a columnar metal structure over a substrate at a first current density by a diffusion limited deposition process, measuring a capacitance of the columnar metal structure to determine a surface area of the columnar metal structure, and depositing three dimensional porous metal structures over the columnar metal structure at a second current density greater than the first current density.