摘要
A nickel-based compound layer was prepared on a nickel plate by anodization in a 75 wt% H3PO4 solution containing NH4F. This layer was then treated by galvanostatic charge/discharge （GCD） until a black outer layer was detached, leaving behind a film on the nickel plate as a binder-free electrode material for supercapacitors. The microstructural characterization shows that the film consists of Ni（OH）2 and NiO, and no fluoride is found in the as-obtained film. Electrochemical tests demonstrate that this fluoride-free film electrode exhibits a high capacitance of 954 F·g^-1 at 7.5 A·g^-1, excellent rate capability （a 19.5 % capacitance reduction with the current density increasing to 120 A.g-1） and cycling stability. Within 3500 cycles, the specific capacitance does not decrease, but rather increases from 840 F·g^-1 to approximately 1092 F·g^-1 in the first 100 cycles at 60 A·g^-1, and remains stable until the aforementioned layer is detached.
A nickel-based compound layer was prepared on a nickel plate by anodization in a 75 wt% H3PO4 solution containing NH4F. This layer was then treated by galvanostatic charge/discharge （GCD） until a black outer layer was detached, leaving behind a film on the nickel plate as a binder-free electrode material for supercapacitors. The microstructural characterization shows that the film consists of Ni（OH）2 and NiO, and no fluoride is found in the as-obtained film. Electrochemical tests demonstrate that this fluoride-free film electrode exhibits a high capacitance of 954 F·g^-1 at 7.5 A·g^-1, excellent rate capability （a 19.5 % capacitance reduction with the current density increasing to 120 A.g-1） and cycling stability. Within 3500 cycles, the specific capacitance does not decrease, but rather increases from 840 F·g^-1 to approximately 1092 F·g^-1 in the first 100 cycles at 60 A·g^-1, and remains stable until the aforementioned layer is detached.
基金
financially supported by the Natural Science Foundation of Guangdong Province, China (No. 2015A030313559)
the Basic Research Project of Knowledge Innovation Program in Shenzhen (No. GJHS20120621155123009)
the Innovation and Cultivation Program of College Students in Science and Technology of (Climbing Program) in Guangdong Province (No. 000018)
