Fig. 2: Experimental and theoretical studies of Li plating mechanism at MXene interface for MXene-configured graphite electrode.

a Schematic diagram of lithium nucleation, horizontal accumulation and planar growth on MXene Ti₃C₂T_x interface. Cryo-TEM images at lithium plating levels of 0.3 (b) and 1.0 (c) mAh cm⁻² with a current density of 0.5 mA cm⁻², in which the red, blue and yellow regions represent crystalline Li metal, LiF and Li₂O nanocrystals, respectively. Insets: fast Fourier transform patterns acquired from the plated Li metal region. d Magnified image of boxed regions in blue from (c), showing well crystal structure. e Atomic-resolution TEM image of the boxed regions from (d), disclosing an interplanar spacing of 2.48 Å for the distance between (110) facets. f Lattice mismatch between (110), (200), (211) and (310) planes of lithium and the hexagonal crystal plane of MXene Ti₃C₂T_x interface. Insets: the lattice matching diagrams between the different crystal planes of Li and MXene Ti₃C₂T_x interface. g Adsorption energies of Li atoms grown along horizontal or vertical orientation at substrates of lithium, MXene Ti₃C₂T_x, graphene and copper.