Mo掺杂NiMnSe2的制备及其超级电容器性能

成分和结构是影响多元过渡金属硒化物电化学活性的关键因素。适当掺杂其他金属元素可以有效提高电极材料的电化学性能。通过简单的一步水热法，在泡沫镍上制备出了一种无黏结剂的Mo掺杂NiMnSe₂(记作Ni_0.8Mo_0.2MnSe₂)。Mo的少量掺杂为电极材料提供了丰富的反应活性位点，大大提高了NiMnSe₂的电化学性能。在1 A·g^-1时，Ni_0.8Mo_0.2MnSe₂的比容量达到1 404.0 F·g^-1。掺杂Mo显著降低了NiMnSe₂的电荷转移电阻和扩散电阻。组装的混合超级电容器Ni_0.8Mo_0.2MnSe₂//AC (活性炭)比容量达到81.6 F·g^-1，且倍率性能优异。在2 A·g^-1下连续充放电10 000周，容量保持率为95.8%，表现出超高的循环稳定性。混合超级电容器Ni_0.8Mo_0.2MnSe₂//AC在376.6 W·kg^-1的功率密度下，能量密度达25.5 Wh·kg^-1，高于NiMnSe₂//AC (17.3 Wh·kg^-1)。

Preparation and supercapacitor performance of Mo-doped NiMnSe2

In this work, we applied a simple hydrothermal method to grow a Mo-doped NiMnSe₂ without binding reagent on the foam nickel (noted as Ni_0.8Mo_0.2MnSe₂). Small amount of Mo substitution for Ni can provide rich reactive sites and therefore greatly enhances the electrochemical performance of NiMnSe₂. The specific capacity of Ni_0.8Mo_0.2MnSe₂ at 1 A·g^-1 reached 1 404.0 F·g^-1. Mo substitution can also decrease the charge transfer resistance and diffusion resistance as well as improve the stability of the material structure. The Ni_0.8Mo_0.2MnSe₂//AC (activated carbon) hybrid supercapacitor (HSC) delivered capacity of 81.6 F·g^-1 and exhibited excellent rate performance. After 10 000 cycles at 2 A·g^-1, the Ni_0.8Mo_0.2MnSe₂//AC HSC maintained 95.8% of the capacity, indicating a high cycling stability. Under the power density of 376.6 W·kg^-1, the Ni_0.8Mo_0.2MnSe₂//AC HSC showed an energy density of 25.5 Wh·kg^-1, higher than those of other similar supercapacitor, implying a high energy storage ability.