【摘要】 采用简单的水热法合成了Al掺杂二氧化锰（MnO₂），并且这一过程实现了MnO₂晶相从β到δ型的可控相变。详细研究了Al掺杂浓度对电极结构和电化学性能的影响。结果表明晶相的可控合成需要KMnO₄、MnCl₂和AlCl₃之间的协同作用，并且Al³⁺起到了重要作用。与纯相MnO₂相比，Al掺杂MnO₂的结晶度降低，比表面积增大，这为电极材料提供了更多的活性位点。当Al³⁺的添加量为3 mmol时，制备的MnO₂-3具有最大的比电容和最高的速率性能。以MnO₂-3为正极，活性炭（AC）为负极组装的不对称超级电容器在400 W/kg功率密度下，能量密度可达18.4 W·h/kg，并且循环2万次后容量仍能保持初始值的90%，表明Al掺杂MnO₂具有一定的实际应用价值。该研究为MnO₂作为高性能的电极材料提供了科学指导。更多还原

【Abstract】 Al-doped manganese dioxide（MnO₂） was synthesized by simple hydrothermal method, and a controllable phase transition of the MnO₂ crystal phase from β to δ was 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 KMnO₄, MnCl₂ and AlCl₃, and that Al³⁺ plays an important role. Compared with the pure phase MnO₂, the crystallinity of Al-doped MnO₂ decreases and the specific surface area increases, which provides more active sites for the electrode material. When 3 mmol Al³⁺ is added, the prepared MnO₂-3 has the largest specific capacitance and the highest rate performance. The energy density of the asymmetric supercapacitor（ASC） with MnO₂-3 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 MnO₂ has certain practical application value. This study provides favorable guidance for MnO₂ as a high performance electrode material.更多还原