Mesoporous Ni-P@NiCo2O4 composite materials for high performance aqueous asymmetric supercapacitors

Abstract

Mesoporous Ni-P@NiCo2O4 composite materials have been fabricated via a facile strategy including solvothermal synthesis of Ni-P and subsequent chemical deposition of NiCo2O4. Due to the synergistic effect between Ni-P and NiCo2O4, the Ni-P@NiCo2O4 composite materials exhibit an enhanced performance (1240Fg−1 at 1Ag−1, 668Fg−1 at 16Ag−1) compared with the bare Ni-P materials (717Fg−1 at 1Ag−1, 106Fg−1 at 16Ag−1) and NiCo2O4 materials (741Fg−1 at 1Ag−1, 457Fg−1 at 16Ag−1). Furthermore, the AC//Ni-P@NiCo2O4 asymmetric capacitor exhibits superior energy/power densities (13.3 Wh kg−1/5.7kWkg−1) and cycling behavior (78.3% retention after 10,000 cycles at 4Ag−1) than the AC//Ni-P asymmetric capacitor (7.4 Wh kg−1/5.7kWkg−1, 63.4% retention after 10,000 cycles at 4Ag−1) and AC//NiCo2O4 asymmetric capacitor (10.4Wh kg−1/5.6kWkg−1, 32.4% retention after 10,000 cycles at 4Ag−1). The high performance makes the mesoporous Ni-P@NiCo2O4 composite materials promising electrode materials for supercapacitors.