Controllable Preparation of Activated Asphalt-Based Carbon-MnO Composites and Its Application in Asymmetric Supercapacitors
A pitch-based activated carbon/MnO composite material suitable for supercapacitors is presented.The MnO-loaded pitch-based activated carbon composite materials(PAC@MnO)were prepared via a combination of compression molding and one-step activation method using petroleum pitch as the source of carbon and manganese acetate as the source of manganese.The PAC@MnO composite materials had a high specific surface area,and their pores were mainly composed of micro-mesoporous pores.As an electrode material for supercapacitors,the effect of different MnO loading amounts on the performance of PAC@MnO composite electrodes was studied in a three-electrode system.Among them,the PAC@MnO-0.3 electrode exhibited a specific capacitance of 344.5 F/g at the current density of 0.5 A/g.A high capacitance of 190 F/g could still be afforded by it even at a high current density of 20.0 A/g,demonstrating an excellent rate performance.The asymmetric supercapacitor configured with PAC@MnO-0.3 anode and PAC@MnO-0 cathode delivered a capacitance retention of 87.24%at a high current density of 5.0 A/g after 3 000 cycles,reflecting a good cycling stability.The uniform combination of MnO nanoparticles and PAC significantly improves the electrical conductivity of MnO and suppresses its volume expansion during the charging and discharging processes,contributing to the excellent electrochemical properties of PAC@MnO composite materials.In addition,the abundant hierarchical pore structure of PAC provides many active sites for the storage of electrolyte ions and channels for the rapid transport of electrolyte ions.
万方数据
维普
