Modeling interfaces between solids: Application to Li battery materials

Abstract

We present a general scheme to model an energy for analyzing interfaces between crystalline solids, quantitatively including the effects of varying configurations and lattice strain. This scheme is successfully applied to the modeling of likely interface geometries of several solid state battery materials including Li metal, Li3PO4, Li3PS4, Li2O, and Li2S. Our formalism, together with partial density of states analysis, allows us to characterize the thickness, stability, and transport properties of these interfaces. We find that all of the interfaces in this study are stable with the exception of Li3PS4/Li. For this chemically unstable interface, the partial density of states helps to identify mechanisms associated with the interface reactions. Our energetic measure of interfaces and our analysis of the band alignment between interface materials indicate multiple factors which may be predictors of interface stability, an important property of solid electrolyte systems.

First-principles study of Li-ion distribution atγ−Li3PO4/metal interfaces

“…7. The formation energies of Li vacancy and interstitial pair at Li metal and Li 3 PO 4 , respectively, were reported as the positive values of 0.82 eV ∼ 2.1 eV, using DFT calculations with atomistic models of Li(100)/β-and γ -Li 3 PO 4 interfaces [42,43]. Our results, which show the negligible amount of Li defects at the interface with Li(100), are consistent with the literatures.…”

Interfacial behaviours between lithium ion conductors and electrode materials in various battery systems

“…66 The chemical and electrochemical stabilities of solid electrolyte-electrode interfaces in ASSLIBs are also studied in detail in recent calculations. [67][68][69][70][71] Most SSEs have limited electrochemical windows from rst-principle calculations, and are thermodynamically unstable against cathode materials and Li metal. Thus the chemical reactions and decompositions of SSEs generally happen at the interfaces.…”

Kinetics‐Controlled Degradation Reactions at Crystalline LiPON/LixCoO2 and Crystalline LiPON/Li‐Metal Interfaces

“…This calculation strongly suggests that no Co-O bond with O atom sticking out of the surface survives contact with LiPON. 20…”