Computational Study on the Li Metal Negative Electrode and Inorganic Solid Electrolyte Interface

Garnet-type Li7La3Zr2O12 (LLZ) is expected to be used as a high-capacity all-solid-state battery with metallic Li as the negative electrode due to its high lithium ion conductivity as well as its non-reactivity with metallic Li. To understand the interface formed by the metal Li and LLZ phases and its stability, we applied first-principles calculations and molecular dynamics methods with neural network potentials to evaluate the interface structure at the atomic and electronic levels. As a result, it was found that a space-charge layer is formed at the interface such that there is an excess of Li in the LLZ phase, while electrons are present in the Li metal phase.