Here we report on the tunable supercapacitance of the Mn 3 O 4 beaded chains synthesized by a simple and low cost electro-spinning process. Tuning is achieved by controlled phase transformation of surface spinel Mn 3 O 4 beaded chains to layered-birnessite MnO 2 nanoflakes through galvanostatic charge-discharge cycling. Phase transformation rate is optimized to get maximum capacitance by controlling the parameters such as applied specific current value, number of galvanostatic charge-discharge cycles, micro-structure of working electrode material and the selection of potential range. A maximum specific capacitance of ∼445 F g −1 and areal capacitance of ∼495 mF cm −2 are obtained at current densities of 0.5 A g −1 and 0.125 mA cm −2 respectively. The superior performance in case of layered-spinel composites among similar nanostructures is due to high surface to volume ratio of the MnO 2 nanoflakes formed from the Mn 3 O 4 beaded chains which in turn give rise to large number of surface active sites for the redox reaction to take place. About 100% of capacity retention and coulombic efficiency are observed for ∼1000 cycles even at a higher current density of 7 A g −1 . Morphological dependence of the phase transformation rate is investigated by preparing two different morphologies of Mn 3 O 4 viz., octahedrons and spherical nanoparticles. © 2017