Construction of NiTe/NiSe Composites on Ni Foam for High-Performance Asymmetric Supercapacitor

Graphical Foam support : A NiTe/NiSe composite electrode supported on a Ni foam is synthesized by using a two-step process involving a hydrothermal method and cyclic voltammetry electrodeposition. The NiTe/NiSe composite electrode exhibits excellent electrochemical performance with a specific capacitance of 1868 F g −1 (5.60 F cm −2 ) at 1 A g −1 and remarkable cycling stability. The asymmetric supercapacitor based on a NiTe/NiSe positive electrode has a high specific capacitance of 94.9 F g −1 as well as a maximum energy density of 33.7 Wh kg −1 and power density of 4000 W kg −1 . NiTe/NiSe composites grown in situ on Ni foam are successfully developed as a binder-free electrode for supercapacitors. The as-obtained NiTe/NiSe composite electrode exhibits excellent electrochemical properties with a higher specific capacitance of 1868 F g −1 (5.60 F cm −2 ) at a current density of 1 A g −1 . In addition, an asymmetric supercapacitor is fabricated with NiTe/NiSe as the positive material and active carbon (AC) as the negative material. The resulting NiTe/NiSe//AC device exhibits a high energy density of 33.7 Wh kg −1 at a power density of 800 W kg −1 , providing good cycling performance that retained 86.2 % of the initial capacitance at 2 A g −1 after 5000 cycles. All of the results illustrate that the NiTe/NiSe electrode is promising for potential application in supercapacitors and other fields.