Selective Synthesis of Perovskite Oxyhydrides Using a High-Pressure Flux Method

Oxyhydrides with multi-anions (O2- andH(-)) are a recently developed material family andhaveattracted attention as catalysts and hydride ion conductors. High-pressureand high-temperature reactions are effective in synthesizing oxyhydrides,but the reactions sometimes result in inhomogeneous products due toinsufficient diffusion of the solid components. Here, we synthesizednew perovskite oxyhydrides SrVO2.4H0.6 and Sr3V2O6.2H0.8. We demonstratedthat the addition of SrCl2 flux promotes diffusion duringhigh-pressure and high-temperature reactions, and can be used forselective synthesis of the oxyhydride phases. We conducted in-situsynchrotron X-ray diffraction measurements to reveal the role of thisflux and reaction pathways. We also demonstrated the electronic andmagnetic properties of the newly synthesized oxyhydrides and thatthey work as anode materials for Li-ion batteries with excellent reversibilityand high-rate characteristics, the first case with an oxyhydride.Our synthesis approach would also be effective in synthesizing varioustypes of multi-component systems.

Automated summary

In this study, new perovskite oxyhydrides SrVO2.4H0.6 and Sr3V2O6.2H0.8 were successfully synthesized. The addition of SrCl2 flux was found to promote diffusion during high-pressure and high-temperature reactions, enabling the selective synthesis of oxyhydride phases. The role of this flux and reaction pathways were investigated using in-situ synchrotron X-ray diffraction measurements. The newly synthesized oxyhydrides exhibited excellent reversibility and high-rate characteristics as anode materials for Li-ion batteries, marking the first application of oxyhydrides in this context. This synthesis approach could also be applied to various types of multi-component systems.