  Lithium metal batteries (LMB) are vital devices for high-energy-density
energy storage, but Li metal anode is highly reactive with electrolyte and
forms uncontrolled dendrite that can cause undesirable parasitic reactions thus
poor cycling stability and raise safety concerns. Despite remarkable progress
made to partly solve these issues, the Li metal still plate at the
electrode/electrolyte interface where the parasitic reactions and dendrite
formation invariably occur. Here we demonstrate the inward-growth plating of Li
into a metal foil while avoiding surface deposition, which is driven by the
reversible solid-solution based alloy phase change. Lithiation of the solid
solution alloy phase facilitates the freshly generated Li atoms at the surface
to sink into the foil, while the reversible alloy phase change is companied by
the dealloying reaction during delithiation, which extracts Li atoms from
inside of the foil. The yielded dendrite free Li anode produces an enhanced
Coulombic efficiency of 99.5 plus or minus 0.2% with a reversible capacity of
1660 mA h $g^{-1}$ (3.3 mA h cm$^{-2}$).
