Multi-color materials NiMn LDH loaded on activated carbon as electrode for electrochemical performance investigation

Layered Double Hydroxide (LDH), as a typical two-dimensional electrochemical storage material, has shown great potential in the field of supercapacitors. Herein, three-dimensional (3D) multicolour NiMn LDH nanoparticles were prepared without substrate using a one-step formula using different levels of Mn and various N sources to assist the hydrothermal reaction. The appearance of the designed materials expressing different colors is owing to the Mn content of the reference playing an important role, where the electrochemical performance and structural stability also become more prominent. Adding a suitable Mn content to the G-NiMn LDH maintains the structural integrity and ultra-flake-like structure, revealing a uniform size of 2 μm compared with B-NiMn LDH. It provides abundant redox sites, enabling the green LDH to exhibit excellent electrochemical performance in appearance (1108F g−1@1 A g−1 in G-NiMn LDH). Furthermore, the in-situ growth of G-NiMn LDH nanomaterials (denoted as G-NiMn LDH/F-AC) on F-doped activated carbon material (F-AC) brought increased active sites, effectively inhibited the accumulation of nanosheets, revealing a good rate capability (78 %@15 A g−1). Moreover, the asymmetric supercapacitor's positive and negative electrodes are G-NiMn LDH/F-AC and biomass carbon, up to 73F g−1. This study methodology offers a novel viewpoint on the manufacture and discussion of LDH for understanding electrode materials' structural and surface chemical characteristics.