Facile Cyclic Voltammetric-Induced Trimetallic Oxides with Shear-Wall Structure Exhibiting Advanced Performance in an Asymmetric Pseudocapacitor

Recently, a multicomponent system in the electrochemical energy-storage field exhibits advantages of both electrochemical activity and electronic conductivity due to its synergistic effects. Herein, a trimetallic oxide thin film of Ni−Mn−Fe is obtained through a facile cyclic voltammetric electrodeposition method. The obtained thin film is grown vertically on Ni substrate to form a unique nanosheet morphology with shear-wall structure. This less crystalline structure is beneficial for the observed faster kinetics due to the rational transport channels, avoiding sluggish charge diffusion. This trioxide thin film displays a maximum capacitance of 3950 F g −1 at a current density of 1 A g −1 , with 1250 F g −1 being obtained at a higher current density of 25 A g −1 and maintaining a capacitance of 865 F g −1 after 10 000 cycles. In addition, by paring this film as a cathode with activated carbon, it delivers a considerable energy density of 194.2 Wh kg −1 at a power density of 0.75 kW kg −1 and still outputs an energy density of 33.2 Wh kg −1 at its highest power density of 19 kW kg −1 . When applied to a practical condition, the cell lights up three red light-emitting diodes (LEDs).