Manganese dioxide (MnO 2) holds significant promise for asymmetric supercapacitors (ASCs) owing to its abundant natural resources, environmental compatibility, and high theoretical specific capacity. However, its practical electrochemical performance is often substantially limited by poor intrinsic electrical conductivity, resulting in actual capacity values far below the theoretical expectations. In this work, we propose an effective strategy to address these limitations by constructing a rationally designed MnO 2 @NiMo-LDH heterostructure. The hybrid MnO 2 @NiMo-LDH electrode exhibits a remarkable specific capacity of 622.8 C g −1 at 1 A g −1 , significantly surpassing that of pristine MnO 2 (148.0 C g −1 ) and NiMo-LDH (426.4 C g −1 ). Furthermore, an asymmetric supercapacitor device assembled with MnO 2 @NiMo-LDH as the positive electrode and activated carbon (AC) as the negative electrode achieves an extended voltage window of 1.7 V and an energy density of 36.4 Wh/kg at a power density of 845.4 W/kg. Notably, the device demonstrates excellent cyclability, retaining 85.45% of its initial capacitance after 10,000 cycles at 2 A g −1 . This study not only highlights MnO 2 @NiMo-LDH as a high-performance electrode material but also provides a generalizable design strategy for developing advanced MnO 2 -based supercapacitor electrodes with enhanced electrochemical properties.
Li et al. (Sat,) studied this question.