Electrochemical Synthesis and Supercapacitive Properties of ε-MnO[sub 2] with Porous/Nanoflaky Hierarchical Architectures

A facile electrochemical method involving a hydrogen coevolution cathodic electrodeposition followed by an in situ electro-oxidation progress has been developed to prepare with a porous/nanoflake hierarchical architecture. Characterizations show that the cathodic-electrodeposition process produces porous spinel , while the subsequent in situ electro-oxidation progress rapidly and completely transforms the spinel to the in nanoflakes without the destruction of the porous matrix. deposits with a porous/nanoflake hierarchical architecture have been found with a high specific capacitance of for the 1st cycle and for the 2000th cycle. The deposits convey an energy density of at a power density of . The porous manganese oxide with good and stable electrochemical performance can be the promising candidate for supercapacitors.