Dual-Seed Strategy for High-Performance Anode-Less All-Solid-State Batteries

Abstract

Interest in all-solid-state batteries (ASSBs), particularly the anode-less type, has grown alongside the expansion of the electric vehicle (EV) market, because they offer advantages in terms of their energy density and manufacturing cost. However, in most anode-less ASSBs, the anode is covered by a protective layer to ensure stable lithium (Li) deposition, thus requiring high temperatures to ensure adequate Li ion diffusion kinetics through the protective layer. This study proposes a dual-seed protective layer consisting of silver (Ag) and zinc oxide (ZnO) nanoparticles for sulfide-based anode-less ASSBs. This dual-seed-based protective layer not only facilitates Li diffusion via multiple lithiation pathways over a wide range of potentials, but also enhances the mechanical stability of the anode interface through the in situ formation of a Ag-Zn alloy with high ductility. The capacity retention during full-cell evaluation is 80.8% for 100 cycles when cycled at 1 mA cm-2 with 3 mAh cm-2 at room temperature. The dual-seed approach provides useful insights into the design of multi-seed concepts in which, from a mechanochemical perspective, various lithiophilic materials synergistically impact upon the anode-less interface. The anode-less all-solid-state battery system reported here operates at room temperature by employing dual seeds in the anode protection layer. Lithiophilic silver (Ag) and zinc oxide (ZnO) nanoparticles promote multistep lithiation for high lithium diffusivity during charge and yield Ag-Zn alloy with high ductility during discharge, both of which contribute to stabilizing the anode|solid electrolyte interface for extended cycle life. image