Stable Lithium Plating in “Lithium Metal-Free” Solid-State Batteries Enabled by Seeded Lithium Nucleation

Abstract

In the “Li ⁰-free” architecture, cells are manufactured with a bare anode current collector and the Li metal anode is plated in situ during the first charging step. While this architecture has many attractive qualities from manufacturing and energy density perspectives, stable Li plating in solid-state “Li ⁰-free” cells can be challenging. It is generally accepted that the Li overpotential affects Li homogeneity in “Li ⁰-free” cells. We demonstrate that the nucleation overpotential for Li plating in solid-state “Li ⁰-free” cells using commercial current collectors can be eliminated by introducing metal clusters that guide Li nucleation. Au is used as model alloying metal cluster. Here, we demonstrate stable Li plating with thickness 16.5 μm (3.3 mAh cm ⁻²) in oxide solid-state electrolyte “Li ⁰-free” cells enabled by Au metal clusters. It is shown that 97% of the in situ plated Li can be reversibly stripped at 60 °C and 2.5 MPa. Conversely, Au interlayers which are flat and continuous instead of clustered in morphology consistently showed short-circuiting during in situ Li plating, limiting Li electrodeposition to <0.1 mAh cm ⁻². These results can help guide future studies of Li nucleation and growth at solid/solid interfaces, as well as offer alternative manufacturing pathways for “Li ⁰-free” solid-state batteries.