Vertically-Oriented Graphene for Supercapacitors

Energy storage devices not only are widely used in nearly all aspects of our daily lives, but also become an essential necessity for the development of renewable energy, which features intermittency. Many researchers around the world are working to improve the energy density, power density, safety, and charging speed of energy storage devices to meet the ever-increasing demands of storing electricity. In this context, extensive research has been and is being carried out on improving the performance of the two major electrochemical energy storage devices, namely batteries and supercapacitors. Traditional rechargeable batteries have shortcomings such as high cost, short life, long charging time, low power density, and potential environmental issues. On the other hand, electrochemical capacitors (i.e., the so-called supercapacitors or ultracapacitors) show great potential in energy storage because of excellent charge/discharge rates, long cycle life, and environmental friendliness. Vertically-oriented graphene (VG) has many characteristics that are ideal for building supercapacitors with improved performance and has been investigated as an electrode material for supercapacitors. In this chapter, supercapacitors using VG-based materials as electrodes are introduced and discussed.