Supercapacitors have garnered substantial attention in recent years due to their ultra-fast charge and discharge rate, excellent stability, long cycle life, and very high power density; for future applications including electric vehicles and portable electronics. I will first talk about supecapacitors based on pillared graphene nanostructures (PGN) grown on Ni foil/foam substrates conformally decorated with transition metal oxide nanoribbons and nanoparticles. The three dimensional electrode architectures of graphene floors with carbon nanotube pillars demonstrate long cycle electrochemical stability; and its integration with the pseudocapacitive transition metal oxides including MnO2 and RuO2 provides superior gravimetric capacitance; exceptionally high energy density and power density. Next, I will talk about PGN supercapacitors with large operational voltage window and ultrafast cycling achieved using organic tetraethyl ammonium tetrafluoroborate electrolyte. Then, I will discuss supercapacitor architectures based on Ni nanodendrites synthesized on Ni foil/foam substrates followed by conformal decoration with RuO2 nanoparticles as a low temperature process, indicating long cycle life, high specific capacitance and high energy denisty. Finally, I will describe equivalent circuit design/analysis for supercapacitors connected in series and in parallel via electrochemical impedance spectroscopy, which are important for practical applications.