Silicon grass based nano functional electrodes for MEMS supercapacitors of improved energy density

Nano-structure functional electrodes for high energy density MEMS supercapacitors have been fabricated by combining atomic layer deposition (ALD) and cyclic deep reactive ion etch (C-DRIE) in MEMS technology. The electrodes were structured with C-DRIE organized silicon grass (Si-g) as the scaffold for conformal coating with ALD nano-layer TiN as the current collector, and electrochemical loading pseudo-capacitive active material. As obtained Si-g/TiN/MnOx on-chip electrode results in large surface gain scaffold with one dimensional ionic diffusion, high conductivity and electrochemical stability current collector, high effective number of redox centers per volume, which enable largely improved energy density.