Controllable synthesis of aluminum doped peony-like α-Ni(OH)₂ with ultrahigh rate capability for asymmetric supercapacitors.

ABSTRACT: Ion substitution and micromorphology control are two efficient strategies to ameliorate the electrochemical performance of supercapacitors electrode materials. Here, Al³⁺ doped α-Ni(OH)₂ with peony-like morphology and porous structure has been successfully synthesized through a facile one-pot hydrothermal process. The Al³⁺ doped α-Ni(OH)₂ electrode shows an ultrahigh specific capacitance of 1750 F g^-1 at 1 A g^-1, and an outstanding electrochemical stability of 72% after running 2000 cycles. In addition, the Al³⁺ doped α-Ni(OH)₂ electrode demonstrates an excellent rate capability (92% retention at 10 A g^-1). Furthermore, by using this unique Al³⁺ doped α-Ni(OH)₂ as the positive electrode and a hierarchical porous carbon (HPC) as the negative electrode, the assembled asymmetric supercapacitor can demonstrate a high energy/power density (49.6 W h kg^-1 and 14 kW kg^-1). This work proves that synthesizing an Al³⁺ doped structure is an effective means to improve the electrochemical properties of α-Ni(OH)₂. This scheme could be extended to other transition metal hydroxides to enhance their electrochemical performance.

SUBMITTER: Wei J 

PROVIDER: S-EPMC9062355 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature