Li₂S-based anode-free full batteries with modified Cu current collector

It is considered that anode-free Li-metal batteries are one of the promising constructions for achieving extremely high energy density, but they still suffer from low Coulombic efficiency, rapid capacity fading and dendrite growth issues. Here, we demonstrate an anode-free full cell with Li₂S as cathode and Au-modified Cu foil as the vacant anodic current collector for achieving a very high energy density up to 626 ​Wh kg⁻¹. The Au-modification (0.168 ​mg ​cm⁻², $ ~0.008 ​cm⁻²) will transform to Li_xAu alloy and solid solution, which can successfully lower the nucleation barrier of Li deposition and induce the dendrite-free Li morphology. As a result, the anode-free Li₂S||Au/Cu full cell exhibits a greatly improved initial Coulombic efficiency of 69% and a stable cyclability over 150 cycles. Our work provides a new route to realize the truly Li-limited Li–S full batteries with much higher overall energy density and greatly stabilized interfacial chemistry.