Carbon nano-onions (CNO) have many attractive properties for energy storage, such as high conductivity, high surface area, and exceptionally fast charge-discharge rates. At Drexel University, CNO is synthesized by annealing of a nanodiamond precursor, which can be easily scaled up to kilogram quantities for industrial applications. CNO has gained significant attention in the last five years for energy storage applications, specifically for electrochemical capacitors (ECs). While ECs are ideal for high power applications, CNO ECs show more than 10x the power density of activated carbon, which is the industry standard. The exceptional performance stems from their non-porous structure, allowing ions to adsorb and desorb 1000x faster than activated carbon. We have also shown an increased performance for CNO compared to carbon black as a conductive additive to activated carbon electrodes. Similar performance could be seen for battery electrodes as well.