Tailoring the supercapacitance of Mn2O3 nanofibers by nanocompositing with spinel-ZnMn2O4

Abstract

Mn2O3 is a pseudocapacitive material and a valuable member of the MnOx family with a theoretical specific capacitance of ~600Fg−1. Despite its good material properties, low electronic conductivity (10−5Scm−1) limits their usage in supercapacitor industries especially in high rate applications. To improve the material properties, Mn2O3 (NFs) composited with ZnMn2O4 (ZMO) were synthesised using a cost-effective electrospinning method and the resultant nanofibers were characterised by larger surface active reaction sites and enhanced charge-transfer kinetics. Phase fraction of ZMO in Mn2O3 NFs, for getting maximum specific capacitance was optimised as 1wt%. About 98% of the capacitance (82Fg−1) was retained after 3000cycles at a higher current density of 20Ag−1. Mn2O3 NFs and their composites are susceptible to electrochemical activation during charge-discharge cycles and cycling-protocol for maximum specific capacitance was found out. Nanofibers and their composites synthesised via electrospinning gives substantial hope in fiber based supercapacitor technology.