Integrated on-chip energy storage is increasingly important in the fields of internet of things, energy harvesting, and wearables with capacitors being ideal for devices requiring higher powers, low voltages, or many thousands of cycles. This work demonstrates electrochemical capacitors fabricated using porous Si nanostructures with very high surface-to-volume ratios and an electrolyte. Stability is achieved through ALD TiN or CVD carbon coatings. The use of Si processing methods creates the potential for on-chip energy storage.