Ultrafine beta-Ni(OH)2 nanosheets with an average diameter of about 14.5 nm have been fabricated by immersing Na(HCO3) 2 nanoparticles into 6 M KOH solution. The multilayer nickel foam system was introduced to improve the cycling stability of ultrafine b-Ni(OH) 2 nanosheets without using acetylene black. The results demonstrated that the specific discharge capacity of the b-Ni(OH) 2 electrode was up to 524.5Cg(-1) at 5Ag(-1) and retained 83.8% after 1000 cycles, which was better than those of other beta-Ni (OH)(2) electrodes obtained using acetylene black as conductors (retained 59.1% after 1000 cycles). Even after 5000 cycles, the specific capacity also maintained 80.8%. In addition, a hybrid supercapacitor was successfully fabricated based on ultrafine beta-Ni(OH)(2) nanosheets and active carbon, the corresponding energy density and power density at 0.1 Ag-1 were calculated to be 20.45 Wh kg(-1) and 75 W kg(-1), respectively. What's more, the hybrid supercapacitor could light up a set of low-voltage light-emitting diodes. (C) 2016 Elsevier Ltd. All rights reserved.