A high-performance and long-lasting, rechargeable Zn-air battery requires a reliable and effective bifunctional catalyst material to facilitate the oxygen reduction and oxygen evolution reactions during the battery operation. Manganese oxide (MnO2) is a promising non-precious perspective due to its multivalency and various polymorphic structures that effectively catalyze oxygen evolution and reduction. In the present work, MnO2 nanowires (NWs) have been integrated with over-reduced graphene oxide (rGO) in various concentrations via a facile hydrothermal route. The synthesized materials, tested in lab-made zinc-air battery devices fabricated using gel polymer electrolyte, exhibit a significant enhancement in the performance and 2-3 times the cycle life compared to the bare MnO2. The ZAB device was tested for galvanostatic charge-discharge technique, and results exhibit a cycle life of 165 h (495 cycles@20 minutes per cycle) when discharged up to 1.0 V at a current density of 5.2 mA/cm2 and displayed a capacity of 731 mAh/gZn. Reduced graphene oxide acts as a support material that enhances the conductivity and surface area of the active material and also provides active sites for catalysis. This work signifies the importance of the engineering of the catalyst, support material, and additives, as slight changes may result in a significant enhancement in the cycle life. The appropriate composition of catalyst and support material and a compatible gel polymer electrolyte facilitates the fabrication of flexible zinc-air batteries for various applications.