Unlocking the in situ Li plating dynamics and evolution mediated by diverse metallic substrates in all-solid-state batteries

The mechanisms of Li deposition behaviors, which overwhelmingly affect battery performances and safety, are far to be understood in solid-state batteries. Here, using in situ micro-nano electrochemical scanning electron microscopy (SEM) manipulation platform, dynamic Li plating behaviors on 10 metallic substrates have been tracked, and the underlying mechanisms for dendrite-free Li plating are elucidated. Distinct Li deposition behaviors on Cu, Ti, Ni, Bi, Cr, In, Ag, Au, Pd, and Al are revealed quantitatively in nucleation densities, growth rates, and anisotropic ratios. For Li alloyable metals, the dynamic Li alloying process before Li growth is visually captured. It is concluded that a good affinity for Li and appropriate lattice compatibility between the substrate and Li are needed to facilitate homogeneous Li plating. Our work not only uncovers the Li plating dynamics, shedding light on the design of solid-state batteries, but also provides a powerful integrated SEM platform for future in-depth investigation of solid-state batteries.