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