Electrodes with novel hierarchical nanoarchitectures can offer many opportunities for achieving the enhanced performance in energy storage. Herein, we have designed and synthesized 3D hierarchical structures of CoAl LDH@Ni(OH)₂ nanosheet arrays (NSAs) by a facile two-step route. Compared with the pristine CoAl LDH NSAs, the hierarchical CoAl LDH@Ni(OH)₂ NSAs represents much better capacitive behaviors. Specifically, under the same test conditions, CoAl LDH@Ni(OH)₂ electrode exhibits the maximum specific capacitance of 1528 F g^_1 (by galvanostatic discharge at the current density of 5 mA cm^_2 in 2 M KOH, based on the total mass; that for CoAl LDH NSAs is only 738 F g^_1) and excellent cycling performance (retaining 92% of its original capacitance after 1300 times of cycling). Such enhanced supercapacitor performances can be attributed to the novel 3D architectures, which can benefit the full contact of the Ni(OH)₂ layer with OH^_ in the electrolyte.