Enhancing ionic conductivity in Ag3PS4 via mechanical amorphization

Amorphous conductors with high ionic conductivity are a promising candidate as electrolytes in all-solid state batteries. In this work, we prepared amorphous Ag 3 PS 4 conductor via a chemo-mechanical milling process, and then characterized its structure and electrochemical properties . The results show that Ag + conductivity of the amorphous Ag 3 PS 4 was remarkably enhanced by three orders of magnitude compared to its crystalline counterpart. Furthermore, the amorphous sample exhibits lower activation energy ( E a ) for ionic conductivity as a function of temperature. Structural characterizations indicate that the tetrahedral [PS 4 ] units were retained in amorphous Ag 3 PS 4 , but the Ag + ions became more liberated than those in the crystalline state, leading to the enhanced migration of Ag + ions, thereby, the ionic conductivity in amorphous Ag 3 PS 4 is drastically increased. This work provides insight into the crucial role of the disorder in raising the ionic conductivity of amorphized chalcogenide materials containing mobile ions.