Fig. 3: Morphological and electrochemical performance of MnO quantum dots well-inlaid carbon nanotubes (MnO@CNTs) anode.
From: Ampere-hour-scale soft-package potassium-ion hybrid capacitors enabling 6-minute fast-charging
a The schematic illustration of MnO@CNTs synthesis procedure and the mechanism for K+ storage. b The optical images of MnO@CNTs film (i), the Cs-corrected STEM image of the MnO QDs (ii) and the SEM image of. MnO@CNTs film (iii). c CV curves of MnO@CNTs electrode at various scan rates of 0.1 to 20 mV s−1. d Contribution ratios of the capacitance (pink) and diffusion (green) in the MnO@CNTs-rGO electrode at different scan rates. e Comparison of the rate performances of MnO@CNTs-rGO with those of carbon-based anode material for PIBs recently reported. f Rate capacities of MnO@CNTs (red) and MWCNTs (green) half-cell at current densities of 0.2, 0.5, 2, 5, 10, 20, and 40 A g–1. g Long cycle performance of MnO@CNTs at 20 A g–1. h Adsorption energies and energy barriers for K+ ion on graphite and MnO@graphite based on DFT calculations.
