Vertically Orientated TiO₂ 1D Lepidocrocite Nanoflakes as Scaffold for Enhanced Li-Metal Anodes

Lithium metal anodes have long been the ideal anode for a variety of cell chemistries owing to their high gravimetric capacity. Dendrite growth, during cycling, however, restricts their practical deployment. Here, a new class of nanomaterials TiB₂derived 1-dimensional lepidocrocite quasi two-dimensional nanoflakes (1DL) are used as basis for creating a Li scaffold, that can be used as an anode-free setup. The 2D nanoflakes comprised of 1DL nanofilaments are synthesized with a bottom-up reaction, directly from commercial 3D-bulk solids at near ambient temperatures and pressures^1,2. The morphology of the 1DL is highly tunable based on processing parameters and can be intercalated with a variety of cations^3,4. Here 1DLs are orientated vertically to guide Li-metal deposition and serve as a Li metal scaffold. This is achieved with a control freezing of an aqueous blade cast slurry. Freeze-drying results in an organized vertically oriented structure. These vertical-1DLs enable easier Li nucleation, with lower overpotentials compared with bare Cu or a normal cast slurry of 1DLs. The vertical-1DL shows an overpotential of -0.06 mA vs -0.08 mA for Cu, a 25% reduction. Leading to a more spatially uniform deposition of Li. Further, 1DL flakes can be intercalated with lithiophilic cations to further improve Li metal deposition and nucleation. Lastly, the -OH rich surface groups on the 1DL NFs surfaces help improve the formation of a uniform solid-electrolyte interphase. These properties enable 1DL nanoflakes that are orientated vertically to serve as a Li-scaffold in an anode-free setup.