Morphology reconstruction of Nikel Cobalt layered double hydroxides induced by electrolyte concentrations triggers high performance of supercapacitive storage

Nikel Cobalt layered double hydroxides (NiCo LDHs) have emerged as ideal electrode materials for supercapacitor due to their high specific surface area and excellent cycling stability. Morphology control plays a unique role in regulating the performance of NiCo LDHs, but there are rare reports to regulate the morphology during energy storage. Herein, the morphology of NiCo-LDHs electrode is optimized for enhancing energy storage by simple activation process with different t concentrations of the electrolyte. During the activation process, electrochemical morphology reconstructed occurs on the electrode surface. With2 M KOH electrolyte the NiCo-LDH electrode transforms from nanosheets to nanoflower, which aids in reducing the distance of ion transport. The reconstructed NiCo-LDH (NiCo-LDH-2) exhibits an ultra-high specific capacitance of 5428 F g-1 at a current density of 1 A g-1, outperforming most of NiCo LDHs. Even at a high current density of 10 A g-1, the capacitance retention rate remains above 77.6% after 1000 charge-discharge cycles. The strategy proposed in the study, which involves concentration-controlled morphology optimization for energy storage enhancement, holds great practical significance for the field of supercapacitors.