Hierarchical Co0.6Mn0.4Se@CoMo layered double hydroxide ultra-thin nanosheet for high performance hybrid supercapacitor

Designing the novel electrode materials with compositing diverse active components and unique microstructures is an effective strategy to enhance the energy storage capacity of supercapacitors. In this work, the hierarchical composite Co0.6Mn0.4Se@CoMo-LDH, which consists of Co0.6Mn0.4Se nanosheets and CoMo-LDH, is grown directly on nickel foam by hydrothermal reaction, solvothermal selenization reaction and electrodeposition. The prepared material has unique hierarchical interconnected nanosheets, which not only increases the contact area with the electrolyte and enhances the electron transfer ability, but also enables the high capacity through the interaction between active materials. Benefiting from these advantages, the prepared material shows a high specific capacity of 1405.2 C g-1 (at current density of 1 A g-1) and an excellent capacity retention of 88.2% after 10000 cycles. Moreover, the hybrid supercapacitor assembled by Co0.6Mn0.4Se@CoMo-LDH and active carbon achieves a high energy density of 71.4 Wh kg-1 at the power density of 1.13 kW kg-1. Meanwhile, the device shows a cycle performance of 106.2% over 10000 cycles. Because of the superior electrochemical performance, Co0.6Mn0.4Se@CoMo-LDH composites electrode has a tremendous potential in upcoming energy storage technologies.