Sparse MnO2 nanowires clusters for high-performance supercapacitors

MnO2 nanowires clusters are electrodeposited onto Ni foam by a cyclic voltammetric technique. MnO2 nanowires, about 20 nm in diameter and up to 200 nm in length, present a sparse grass clusters structure. As cathode material for supercapacitors, MnO2 nanowires clusters exhibit superior pseudocapacitance performances with high specific capacitances (1080 F g− 1 at 4 A g− 1 and 415 F g− 1 at 30 A g− 1) as well as excellent large-current cycling stability, making it suitable for high-performance supercapacitor application. The improved pseudocapacitance performances are attributed to small size, large surface area and high dispersion degree of MnO2 NWs, as well as 3-Dimension structure of Ni foam, which provide faster ion and electron transfer, larger reaction surface area, higher electrochemical activity, leading to faster reaction kinetics and higher material utilization ratio.

► Sparse MnO2 nanowires clusters on Ni foam.
► The pseudocapacitance is up to 1080 F g− 1, and the large-current cycling performance is excellent.
► Characteristics: small size, large dispersion degree of nanowire cluster, 3D structure of Ni foam.