In order to provide amenities and infrastructure to current and future generations a sustainable energy sources are essential.For the development of these amenities and infrastructure renewable energy plays a significant role.In this 21st century,the development of science,technology and innovation has helped to accomplish a substantial increment in the portion of renewable energy by replacing the use of fossil fuels which is associated with the pollution.To mitigate the energy crisis many industrial countries are mainly focused on the research and production of energy storage technologies.Electrochemical energy storage devices such as zinc air batteries and alkaline fuel cells are on a growth trajectory which cost less to operate.For the improvement of a number of renewable energy technologies,including solar fuels production and metal–air batteries improved catalyst for the OER should be created.In the past decades creating durable,proficient and inexpensive electro-catalyst for OER has been major challenge.In the field of metal air batteries ORR plays a vital role in the process of energy conversion.A key element in this search is the development of reliable and cost-effective catalysts for use in electrochemical energy conversion processes such as the oxygen evolution reaction（OER）and the oxygen reduction reaction（ORR）,both of which are critical to the efficiency of direct-solar and electrolytic water-splitting systems,fuel cells and metal-air batteries.Of all metal oxide cobalt-based spinel metal oxides are the most stable and active catalyst towards both the OER and ORR.It is important to develop stable electro-catalyst that helps to increase the efficiencies of both OER and ORR.The main objectives of this thesis are as follows;1)To study the preparation and modification of MnCo2O4 and MnCo2O4/MWCNT spinel electro-catalyst for oxygen evolution reaction and oxygen reduction reaction using hydrothermal and electrospinning technique2)To study the basics of metal-air batteries and its virtues to the modern need of energy consumption.In this research,MWCNT was distributed through an ultrasonic process that is used as a nanocomposite preparation technique to provide the dispersion and stabilization of MWCNT in solvent or composite materials in a normal setting.The results of this research demonstrated1)The surface morphology of the catalyst powders prepared by these two methods weresignificantly different.From the SEM and BET test results,the product MnCo2O4/MWCNT electrospinning method is a typical fibrous morphology with a thickness of approximately 1μm and a specific surface area of 67.85 m~2/g,which is significantly larger than that of H-MnCo2O4（51.93 m~2/g）which is amorphous agglomerated particles.A greater specific surface area means more active catalytic sites,a larger effective contact area with electrolyte solution and oxygen molecules,which can naturally increase the catalytic activity of the catalyst.After the introduction of MWCNT,the lattice oxygen or highly oxidative oxygen species in the core oxygen spectrum has been improved.The concentration of oxygen vacancy was amplified by the introduction of MWCNT,which increased 17.81 per cent and 6.31 per cent respectively for H-MnCo2O4 and E-MnCo2O4.Compared to manufacturing methods,E-MnCo2O4/MWCNT shows a higher lattice oxygen/high-valent oxygen ion pair than H-MnCo2O4/MWCNT by3.23 per cent.Lattice oxygen/high-valent oxygen ion pairs(O2-or O2-/O-)play an important role in the oxygen precipitation reaction of the water decomposition process.Hence,MWCNT introduced into the H-MnCo2O4 and E-MnCo2O4 electro-catalysts can improve the bi-functional electrochemical activities for OER and ORR.2)Also,EIS,ECSA and the long-term stability was slightly improved after bringing MWCNT up to catalysts.Besides,the electro-catalysts prepared by the electrospinning method presented a more specific surface area（2020 cm）~2.The electrochemical properties of catalysts prepared by the electrospinning method display better performance than the hydrothermal fabricated one.The onset potential of E-MnCo2O4/MWCNT was observed to the significantly lower（～1.53 V）than H-MnCo2O4/MWCNT（～1.55 V）,E-MnCo2O4（～1.56 V）,and H-MnCo2O4（～1.57 V）.Meanwhile the potential at 10 m A s-1,E-MnCo2O4/MWCNT exhibited significantly lower（～1.759）than E-MnCo2O4（～1.766 V）,H-MnCo2O4/MWCNT（～1.775V）,and H-MnCo2O4（～1.798 V）.Tafel slopes of E-MnCo2O4/MWCNT（114.97 m V/dec）and E-MnCo2O4（117.49 m V/dec）indicated lower than those samples prepared by the hydrothermal method,i.e.H-MnCo2O4/MWCNT（119.87 m V/dec）and H-MnCo2O4（140.19m V/dec）.These Tafel results show the same direction with LSV and BET results which consider the electrocatalytic activity of E-MnCo2O4/MWCNT over other samples.Electro-catalyst MnCo2O4 prepared by hydrothermal and electrospinning methods has been compared to the morphology that affects the bi-functional electrochemical performance of both OER and ORR.Based on the experimental results of the study,we can suggest that MWCNT decoration is an important element to improve a better electrochemical activity of MnCo2O4 catalysts.Also,the electrospinning method is a better way to prepared MnCo2O4 electro-catalysts,comparing to the hydrothermal method.Among all as-prepared electro-catalysts,the E-MnCo2O4 with MWCNT decorating presents the beneficial morphology and best electrochemical properties.As a cheap fabrication way and efficient bi-functional electroactivity of E-MnCo2O4/MWCNT electro-catalysts are one of great significance for the application of oxygen energy storage and conversion devices.