Fabrication of Ni(OH)2 coated ZnO array for high-rate pseudocapacitive energy storage

The present communication reports on the first electrodeposition of Ni(OH)2 on ZnO array supported on Ni foam. When applied as a binder-free electrode material for pseudocapacitive energy storage, the resulting ZnO@Ni(OH)2 array exhibits a high specific capacitance of 2028 F g−1 at a current density of 10 A g−1 with good cycling stability. Meanwhile, the array exhibits a superb rate capability. Even at an extremely high current density of 100 A g−1, the array still shows a very high specific capacitance of 1059 F g−1.