Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the str...Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the structure and electrochemical properties of electrode materials were studied in detail.The results show that the controlled synthesis requires a synergy between KMnO_(4),MnCl_(2)and AlCl_(3),and that Al^(3+)plays an important role.Compared with the pure phase MnO_(2),the crystallinity of Al-doped MnO_(2)decreases and the specific surface area increases,which provides more active sites for the electrode material.When 3 mmol Al^(3+)is added,the prepared MnO_(2)-3 has the largest specific capacitance and the highest rate performance.The energy density of the asymmetric supercapacitor(ASC)with MnO_(2)-3 as the positive electrode and activated carbon(AC)as the negative electrode can reach 18.4 W·h/kg at the power density of 400 W/kg,and the capacity can maintain 90%of the initial value after 20000 cycles,indicating that Al-doped MnO_(2)has certain practical application value.This study provides favorable guidance for MnO_(2)as a high performance electrode material.展开更多
基金Project(202203021221138)supported by the Collaborative Innovation Center for Shanxi Advanced Permanent Materials and Technologythe 1331 Engineering of Shanxi ProvinceFundamental Research Program of Shanxi Province,China。
文摘Al-doped manganese dioxide(MnO_(2))was synthesized by simple hydrothermal method,and a controllable phase transition of the MnO_(2)crystal phase fromβtoδwas achieved.The effects of Al doping concentration on the structure and electrochemical properties of electrode materials were studied in detail.The results show that the controlled synthesis requires a synergy between KMnO_(4),MnCl_(2)and AlCl_(3),and that Al^(3+)plays an important role.Compared with the pure phase MnO_(2),the crystallinity of Al-doped MnO_(2)decreases and the specific surface area increases,which provides more active sites for the electrode material.When 3 mmol Al^(3+)is added,the prepared MnO_(2)-3 has the largest specific capacitance and the highest rate performance.The energy density of the asymmetric supercapacitor(ASC)with MnO_(2)-3 as the positive electrode and activated carbon(AC)as the negative electrode can reach 18.4 W·h/kg at the power density of 400 W/kg,and the capacity can maintain 90%of the initial value after 20000 cycles,indicating that Al-doped MnO_(2)has certain practical application value.This study provides favorable guidance for MnO_(2)as a high performance electrode material.
