Conventional energy storage devices have relied upon the ability of the electrochemically active materials to store the charge in the wide potential region with high Coulombic efficiency. Transition metal oxides are considered as ideal electrode materials in various energy storage devices, owing to their unique features, namely, high theoretical specific capacity; pseudocapacitive nature and ability to deliver large energy and power density. However, it suffers from many drawbacks, such as, low electronic conductivity and capacity fading with number of cycles. To address these shortfalls metal oxides are, usually, embedded within a conductive carbon-based matrix (for example graphene). The use of graphene would afford easy pathway for electron movement and increases the surface area for higher interaction of active electrode materials with electrolyte. Subsequently, graphene based transition metal oxides composites have attracted active research pursuits in synthesizing the low cost effective electrode materials for energy storage devices. In this work, we report a facile and economic approach to produce manganese oxide nanorods amalgamated on the graphene sheets (MnO2@G) powders with an aim to achieve improved electrochemical activity. This electrochemical exfoliation strategy demonstrates a synthesis scheme from the graphite sheets at a constant voltage of 10 V in the MnSO4 bath solution, the outcome of which are the black shinny flaky powders. The crystallinity MnO2@G powders' was confirmed by XRD analysis. The TEM reveals the incorporation of MnO2 nanorods on the exfoliated few layers of graphene nanosheets. The physiochemical and electrochemical properties were tuned by varying concentrations of MnSO4 solutions. Interestingly, it was found that the yield of graphene as well as the performance of MnO2@G governed by the concentrations of salt solution. The degree of graphitisation in the as prepared materials was investigated by depth analysis in the Raman spectroscopy. Further, the electrochemical performances of MnO2@G were examined by cyclic voltammetric, charge-discharge and electrochemical impedance spectroscopy studies in a three electrode set-up. It was discovered that the MnO2@G composite prepared using 0.1 M MnSO4 solution has a delivered better electrochemical performance. To realise the practical applicability of the MnO2@G composite, flexible light-weight solid-state prototype asymmetric supercapacitor was fabricated using MnO2@G as positive and graphene as negative electrode. The fabricated devices exhibited ample storage capacity along with high energy density and powder density which were capable of powering consumer electronics applications. Thus, in the present work we have developed a cheap and effective electrochemical preparation of exfoliated MnO2@G composites in high yield. This scheme could serve as precedent to the development of potential electrode materials for energy storage devices.