Capacitance-soaring phenomenon induced by CuO electrode reconstruction with metastable Cu(OH)₂ nanowires

Metastable Cu(OH)₂ nanowire precursors are reconstructed to interconnected CuO nanosheets through cyclic voltammetry. The capacitance retention rate of the electrode increases to 320% of its original value at a current density of 60 mA cm^-2 after 10 000 charge and discharge cycles, and a strange capacitance-soaring phenomenon occurs. Thus, it can be inferred that the structural reconstruction and phase transition of the metastable phase of the electrode during the electrochemical process may also improve the electrochemical performance, which necessitates the reconsideration of the non-stable state of the electrode. Furthermore, it should not be uniformly labeled as unacceptable.