Surface functionalization of the terraced surface-based current collector for a supercapacitor with an improved energy storage performance

Due to its high electrical conductivity and excellent chemical/physical durability, the nickel (Ni) foam is conventionally used as the current collector of supercapacitors that are characterised by high power density, rapid charge/discharge cycles, and long lifespan. However, the limitation of the current collector is its flat surface, which leads to a low rate performance and cycling stability. Therefore, a rational design of the current collector and the electrode material is an essential interfacial engineering technology to be developed to improve the electrochemical performance of the collector. In the present study, applying the surface functionalization of the Ni current collector with the nano-sized stairs of the terraced surface resulted in the electrochemical performance of a remarkable capacitance (210 F g ⁻¹ at the current density of 0.5 A g ⁻¹ ), excellent rate performance of 83%, and outstanding cycling stability of 89% after 10,000 cycles. The proposed design has obvious advantages in terms of the high contact area between the current collector and electrode material, on the one hand, and the uneven surface, one the other hand, leading to an excellent rate performance and an outstanding cycling stability. This remarkable capability demonstrates that the surface functionalization of the current collector is a promising technology for high-performance supercapacitors.